Research Report GCISC-RR-Ol

Climate Profile and Past Climate Changes in Pakistan

M. Munir Sheikh, Naeem Manzoor, Muhammad Adnan, Javeria Ashraf Arshad M. Khan

June 2009

Global Change Impact Studies Centre Islamabad, Pakistan

Published by: Global Change Impact Studies Centre (GCISC) National Centre for Physics (NCP) Complex Quaid-i-Azam University Campus P.O. Box 3022 Islamabad-44000 Pakistan

ISBN: 978-969-9395-04-8

@GCISC

Copyright. This Report, or any part of it, may not be used for resale or any other commercial or gainful purpose without prior permission of Global Change Impact studies Centre, Islamabad, Pakistan. For educational or non-profit use, however, any part of the Report may be reproduced with appropriate acknowledgement.

Published in: June 2009

This Report may be cited as follows: Sheikh, M.M., N. Manzoor, M. Adnan, 1. Ashraf and Arshad M. Khan, (2009), Climate Profile and Past Climate Changes in Pakistan, GCISC-RR-Ol, Global Change Impact Studies Centre (GCISC), Islamabad, Pakistan.

FOREWORD

Global change Impact Studies Centre (GCISC ) was established in 2002 as a dedicated research centre for climate change and other global change related studies , at the initiative of Dr. Ishfaq Ahmad, NI, HI, Sf, thc then pecial Advisor to the Chief Executive of Pakistan. The entre ha since been engaged in research on past and projected climate change in different sub regions of Pakistan' corresponding impacts on the country's key sectors; in particular, Water and Agriculture' and adaptation m asurcs to counter the negative impacts.

The work described in this report was carried out at GCISC and 'was supported in part by APN (Asia Pacific etwork for Global hange Research), Kobe, Japan, through it CAPaBLE Programme under a 3-year capacity enhancement cum research Project titled "Enhancement of National Capacities in the Application of Simulation Models for the Assessment of Climate Change and its Impacts on Water Resources, and Food and Agricultural Production", awarded to GClSC in 2003 in collaboration with Pakistan Meteorological Department (PMD).

It is hoped that the report will provide us ful information to national planners and policy rnakcrs as well as to academic and research organizations in the country on issues related to impacts of climate change on Pakistan.

The keen interest and support by Dr. Ishfaq Ahmad, Advisor (S & T) to the Planning Commission and useful technical advice by Dr. Amir Muhammed Rector, National University for Computer and Emerging Sciences and Member, Scientific Planning Group, APN, throughout tile course of this is work arc gratefully acknowledged.

Dr. Arshad M. Khan Executive Director,

GCISC

PREFACE

The earth's climate system has demonstrably changed on both global and regional scales since the pre-industrial era (1860) (IPCC, 2001). There is now a new and stronger evidence that most of the warming observed over the last 50 years is attributed to human activities. The concentration of the main greenhouse gas, 02, which stood at a level of 280 ppm for the period 1000-1750, increased to 379 ppm in 2005 (35% increase). The global surface temperature increased during the 20th century by 0.6° while the 100 year linear trend increased to 0.74°C during 1906-2005. The second half of the last century saw the temperature changes as 0.128 °C per decade from 1955-2005 and 0.177 °C per decade from 1980-2005 with 1990s a the warmest decade in. the instrumental record since 1860 (TPCC AR4 2007).

Such a situation called for the past climate changes in Pakistan to be assessed using the mo. t appropriate statistical techniques to serve as the baseline patterns to help get an insight into how vulnerable or resilient arc different sectors. For this the metrological data of some 54 stations for the period 1951-2000 (or for the period data is available) are analyzed as de. cribed in this report. The details of different chapters are as follows:

Chapter 1 is on the General Climate Profile. Pertinent geographic, physiographic and climatic details of the country are included in thi chapter. Different climate zones and' their details hill torrents in the country and the demographic and agrarian aspects arc further added in this chapter. Chapter 2 on the Climate Data Monitoring System in Pakistan. The facilities available in this connection with Pakistan Meteorological (PMD) and the type of data used in this report are outlined in this chapter. Chapter 3 is on the Temperature Regime over Paki tan. The chapter, studded with necessary tables and figures, highlights the spatial temperature distribution over the country and in different climatic zones. This is based on the 30-year normal data for the period 1961-1990 and the monthly temperature data for the period 1951-2000 or for the period data is actually available. Chapter 4 is on the Rainfall Distribution over Pakistan and contains details almost in line with the details given for temperature. Chapter 5 is on the Past Climate Changes in Paki tan. Changes using the trend analysis arc worked out for the climate parameters of Temperature (Mean, Maximum and Minimum) and Precipitation On annual and sea. onal basis for all the stations and for different zone. These changes are presented in the contour and map form and results arc extracted. The chapter also includes the extreme trend analysis carried out on monthly basis on temperature and precipitation and number of stations showing increasing or decreasing trend for each zone. Chapter 6 is on the Climate Variability and Change in the Mountainous North of Pakistan. The region comprises parts of Karakoram, Hindukush and Himalayan Ranges. Chapter 7 is on the Analysis of Driest Periods and Drought Vulnerable Areas in Pakistan. Driest periods based on the 30-ycar normal period (1961-90) and their percentages are worked out for each station and for each season. Areas remaining dry for more than 50% of the time arc treated as drought vulnerable areas. The vulnerable areas in different part. in different

II

seasons are then discussed in the context of likely rainfall during the subsequent seasons. Chapter 8, the last chapter, is on the ENSO and NAO influences over the Weather of Pakistan. The natural forcing phenomena like El-Nino Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) developing occasionally in the Equatorial Pacific Ocean and North Atlantic Ocean respectively have been studied in the context of their influence 0ver the weather of Pakistan by analyzing the historical data of rainfall for the period 1951-2000 supplemented by the re-analysis CEP pressure and RU TS 2.0 precipitation data.

List of Acronyms

Most of the Acronyms and abbreviation, wherevcr they appear in text, are defined.

IX

Chapter 1

General Climate Profile

1.1 Geographic and Physiographic Features

Pakistan is a country within South Asia and located approximately within the latitude. 24°N to 37° N

and longitudes 61°E to 76°E. It i. bordered on the west by Iran, on the west and northwest by

Afghanistan on the north and northeast by hina, on the east and southeast by India, and on the outh by

the Arabian Sea. The country has an area of 796,09.6 sq. km or 307 375 sq. miles, excluding the ection

of Kashmir under its control. Its republic consist') of the province of Punjab, orth West Frontier

(NWFP) indh and Balochistan. In addition, some areas are administered directly by the federal

Government, as are the high altitude Northern Areas A), the tribal areas along the border with A

fghanistan and Azad Jammu & Kashmir CAlK). Physically it is the vast valley of mighty Indus River

and its tributaries, running through the whole country as its bloodlines. Northern Pakistan inherits one

of the highest lands of the world. The three great mountain range: Himalaya, Karakorams and the

Hindukush meet in a very complex system of mountains, separated by narrow gorges of the rivers.

South of the northern highlands and west of the Indus River plain are the Safcd Koh Range along the

Afghanistan border and the Sulaiman Range and Kirthar Range, which define the western extent of the

province of indh and reach almost to the southern coast. The lower reaches are far more arid than those

in the north, and they branch into ranges that run generally to the outhwest across the province of

Balochistan. Several large passes cut the ranges along the border with Afghanistan. Among them are

the KJ10jak Pass, about eighty kilometers northwe. t of Quetta in Balochistan: the Khyber Pas s, forty

kilometers west of Peshawar leading to Kabul in Afghanistan; and the Baroghil Pas: in. the far north,

providing access to the Wakhan Corridor. r css than a one-fifth of Pakistan's laud area ha the potential

for intensive agricultural usc. r early all of the arable land i actively cultivated but outputs arc Jow by

world standards.

Some areas below 300 N also constitute the desert areas. In the sub-tropic: there is a relatively

continuous series of deserts extending from the Arabian Desert, which abuts the Sahara, to the Thar

Desert of Pakistan. and India. The Thar Desert span the border betwc n India and Pakistan, with the two

countries sometimes applying local names to their parts of the Thar. I.n Pakistan, the south em part is known as Sindh desert and the northern part is known as Cholistan Desert. A small area to the

northwest of the 1 har in Pakistan is known

1

1.

as Thai Desert. This desert is a transition zone between precipitation producing mechanism. The

semi-permanent thermal low over the deserts in the pre-monsoon period con titutes among other a

predictor for the monsoon rains from Arabian Sea in Pakistan.

Some of the main physiographic features of Pakistan are shown in Fig. 1.1

ourcc: http://www.magazinc.com.[lk/travelfPakigClIl/maps!

Fig. 1.1: Physical Map of Pakistan

1.2 Climatological Features of Pakistan

Pakistan lies in sub-tropic and party in the temperate region, A large part of Pakistan is arid to erni-arid

with some areas a hyper-arid in the lower southern half of the country. The coastal climate i confined

to a narrow strip along the coast in the south and south east and a humid belt along the sub-montane

regions of Himalaya. The Aridity Index Map of Pakistan based on C.W. Thornthwaitc (1931), PE

(Potential Evapotranspiration) Index (1) is shown in Fig. 1.2. Formula used for calculating the PE

Index is as follows:

The index (I) follows the criteria: 31 < 1 a Humid, 16 < J < 31 a Semi arid, 10 < I as arid and I < 10 as

Hyper arid.

2

2. 3. Potential Evapotranspiration or PE is a measure of the ability of th atmosphere to remove

water from the surface through the process of evaporation and tran piration assuming no control over

water supply. Potential Evapotranspiration requires energy for the evaporation process and major ource of this energy i from the sun.

32

Z8

36

3-4

30

26 LEGEND 31<1 1e<'.< a1 10<1 < 16

1<10

62 64 66 S8 70

Fig. 1.2: Aridity Index Map of Pakistan (1951-2000)

1.3 Climatic Seasons in Pakistan

There are four distinct climate seasons in the country:

Monsoon (June to eptember)

The all Pakistan Monsoon Season in the country is from June to September and has it rainfall

sources both from the Arabian Sea and the Bay of Bengal. The mon oon rains from the Arabian

Sea commenc earlier anytime during June wherea the onset of the monsoon season from the Bay or Bengal is July 1 on the average. The area weighted precipitation during the men oon eason

stand around 55% of the total annual rainfall over Pakistan.

3

Winter (December to March) Region above 30° generally receive winter rains due to the pas ing western disturbances. These

disturbance and other circulation system, mostly active in the winter and in the transition period of

the pre-monsoon, arc the main sources of precipitation over the western part . In the far north, the

western disturbances are active more or less throughout the year. Greater Himalayan region above

35°N receives the winter precipitation mostly in the form of now and ice. The snow and glacier

melt keeps the Indus Basin River (Indus, Jhelum and Chenab) perennial throughout the year. The

area weighted precipitation during the season stands around 30% of the total rainfall over Paki tan.

Pre-monsoon ( April-May) The period pril to May and even part of June or at times whole of June is extremely hot and dry. In

these months, a semi-permanent thermal low develops over parts of Balochistan province and

adjoining parts of Sindh and outhern Punjab which plays a vital role during the monsoon season in

facilitating the flow of maritime air masses from the Arabian Sea to flow uninterrupted to the

sub-montane regions or to other parts of the country depending upon the prevalent weather

conditions. The area weighted rainfall during this ea 'on is around 12% of the total annual

rainfall.

Post-monsoon (October- Novcmber) The season is usually very dry and constitutes the transition zone between the monsoon and winter

rainfall seasons. The rainfall at the most remains around 4% of the total area weighted rainfall of

Pakistan.

1.4 General Climate Zoning of Pakistan Based on the phy iographic and climatic feature of the country, we divided the geographical area of

Pakistan into six major zones as are shown in Table l.1 and Fig. 1.3.

4

4.

Regions Meteorological stations in the Regions

Zone I(a): Greater Himalayas Astor, Bunji, Chilns, Chjtral, Dir Dro h, Gilgit, (Winter dominated) Gupis, Skardu Zone I(b): Sub-montane region and Balakot, Garhi Dupatta, Islamabad, Jhelum, Kakul, Monsoon dominated Kotli, Lahore, Murrcc, Muzaffarabad, Saidu harif

Sialkot Zone II: Western Highlands Cherat, D.l. Khan Kohat Parachinar Pe hawar,

Risalnur Zone 11I: Central & Southern Punjab Bahawalnagar, Bahawalpur, Faisalabad, Khanpur,

Mianwali, Multan, Raffiquc, Sargodha Zone IV: Lower Indu Plains Chhor, Hyderabad, Jacobabad, Nawabshah, Padidan,

Rohri Zone V(a) : Balochistan Plateau Barkhan Kalat, Khuzdar, Lasbela, Quetta Sibbi, (Northern) Zhob (Sulaiman & Kirthar Ranges) Zone V(b): Balochistan Plateau Dalbandin, okkundi, Panjgur I (Western) Zone VI: Coastal Belt Badin, Jiwani, Karachi, Pasni

;""

Fig. 1.3: Climate Zone of Pakistan

5

Table 1.1: Climatic Zone of Pakistan

1.5 Details of the Zones

1.5.1 Zone I (a): Greater Himalaya (winter rain dominated) Stretching in the north, from east (0 west, are a series of high mountain rang which separate Pakistan

from China, Russia and Afghanistan. They include the Himalayan, the Karakoram and the Hindukush

Ranges. With the assemblage of 35 giant peaks 24,000 ft (7 315 m) high, the region i the climber's

paradise. M any peaks arc higher than 26 000 ft. K2, th world’s second highest peak in the Karakoram

Range tops at 28,250 ft. The region abounds in glaciers with sizable ones in the Karakoram Range.

Summary of glaciers so far identified in this zone is shown in able 1.2.

Table 1.2: Summary of glacier inventory

Pakistan has more glaciers than any other land outside the 01tl1 and South Poles. Paki tan's glacial area

covers some 13,680 sq. km. which reprc sents an average of 13 per cent of mountain region of the

upper Indu Ba in. Paki tan's glaciers can rightly claim to posse the greatest rnass and collection of

glaciated pace on the face of earth. III fact, in the lap of the Karakoram of Pakistan, alone there are

glaciers whose total area would add up to above 6,160 sq. km. To put it more precisely, as high as 37

per cent of the Karakoram area is under its glaciers against Himalayas' 17 per cent and European Alps'

22 per cent. The Karakorarns have one more claim to proclaim; its southern flank (east and west of the

enormous Biafo glacier) has a concentration of glaciers which works out to 59 per cent of its area

Bes ides these peaks and glacier the region abound in large lakes the green valley, numerou treams and

rivulets, fore ts of pine and junipers, and a vast variety of fauna and flora. South of the high mountains

the ranees lose their height gradually and ettle down

6

5.

finaJly In the Margalla Hill (2,000-3 000 ft) in the vicinity of Islamsbad Different mountain ranges in orthern PakIstan are shown ln Plg. 1.4.

Source: ICIMOD, Nepal Fig. 1.4: Northem ountain Ranges in Pakistan

1.5.2 Zone I (b): Sub-montane Region (Monsoon rain dominated) The region is located on the southern slope of the Himalayan Mountains within about 33° to 35° .

Elevation mostly range from 600 to around 2000 meters. This is a monsoon dominated region and

practically extends up to "'1.5 ON and includes also the stations such as Jhclum, Sialkot and Lahore

with elevations ranging from two hundred to six hundred meters.

1.5.3 Zone II: Western Highlands Th region spreads from the Swat and Chitral bills in the north-south direction, and covers a large

portion of the North- West Frontier Province North of the river Kabul their altitude ranges from 5

000 to 6,000 feet in Mohmand and Malakand hill. . South of the river Kabul spreads the

Koh-e-Sufaid Range with a g acral height of 10,000 ft. Its highest peak,

7

Skaram, is 15,620 It high. South of Koh-e-Sufaid are the} chat and Waziristan hills (5,000 ft.) which

are traversed by the Kurrum and Tochi rivers and are bounded on south by Gomal River. South of the

ornal River, run the Sulaiman Mountains for a di tance of about 483 km in a north-south direction.

Takht-e-Sulaiman is the highest peak in this zone with top at 11,295 ft (3 423 meters). The region lies

on the path of passing western disturbances carrying moisture laden winds from the Mediterranean ea

and give the region a due share of their moisture in winter.

1.5.4 Zone III: The Punjab Plains (Central and Southern Punjab) The Punjab plains also termed as pper Indus Plain comprise mai.nly the province of Punjab. The region

comprises the fertile land of river Indus and its five tributaries viz. Jhclum Chcnab, Ravi Sutlej and

Beas. A belt of thick and fertile alluvium ha been formed by the Indus Basin rivers. Almost whole of

the Province of Punjab is covered by these alluvial deposits in a contiguous strip. These flood plains

are characterized by flat land Iorrn criss-cro ed by a network of irrigation canals. The area is gently

sloping from orth-East to South-We t with levations of about 984 ft (300 Ill) in the extreme north to

about 290 ft (8 rn) in its extreme .outh. The Potohar Upland commonly called the Potohar Plateau, lies

to the south of northern mountains and is flanked in the we t by River Indus and in the east by River

Jhelum. In this plateau, there are a few outlying spurs of Salt Range in the outh, and those of Khair

Murad and Kala Chitta ranges in the north. The importance of the Sal Range lies in the large deposits

of pure alt at Khewra and Kalabagh and the large seams of coal at Dandot and Makerwal.

1.5.5 Zone IV: Lower Indus Plains The lower Indu Plains carry down the water of all the tributaries of Indus River down to the Arabian

Sea. Like the Punjab province, th se are also largely made up of fertile alluvium thousands of feet thick,

transported and depo ited by pre-historic river systern . The Indus plains, in all including Punjab Plain,

arc about 16,000 km (1000 mile ') in length, In Punjab, the broade t portion of the plain is about 320 km

(200 miles) and the narrowest portion is about 12 km (80 miles) wide with deserts on one side and

ulaiman mountains OIl the other. This is actually the divide line of the Punjab and Sindh Provinces. It

i sometimes called the Indus corridor. The area on the up trearn ide is called the ppcr lndus Plain and

below this as the Lower Indus Plains.

8

1.5.6 Zone (a & b) The Balochistan Plateau

The Balochistan Plateau lies in the east of Suliman Range. The altitude is around 2,000 ft (610

meters). The phy ical features of the plateau drastically vary but mountain and basins

pre-dominate the scene. The mountains arc carved off by numerous channel and hill torrents,

which get water only after rains. Important rivers located in this plateau are Zhob, Bolan and

Mulla in the north eastern portion of Balochistan. Kalat is the most important plateau at

7,000-8,000 ft (2135-2440 meters) located in the centre of Balochistan. The largest desert i found

in Balochistan, the largest of which is Hamun-c Mashkhel which is 87 krn long and 35 km wide.

The Dasht and Kharan desrts of Balochi tan lie towards the western border of Pakistan with Iran.

Average annual rainfall in this area i less than 100 mm. It has a mixed land form compri ing eroded

soft sedimentary rocks, vast tracks of sandy/gravelly wastelands with patches of loamy soils

formed by the hill torrents transporting the sediments from the upper catchment areas.

1.5.7 Zone VI: Coastal Belt The coastline of Pakistan is around 990 km. long; 270 km. belonging to the province of Sindh and

720 km. to the Balochistan. The entire coastline of Sindh is studded with dense forests of

mangroves, whereas the coastal belt of Balochistan is barren except for a few spots. Most of the

Makran coast was earlier underdeveloped with deserted beaches and only a few fishing villages.

Coastal highway now built and completed during 2005 from Karachi to Gwadar and the

construction of Gwadar Deep ea Port will boost up economic activities in the coastal region.

1.6 Major Hill-Torrents of Pakistan The whole of Pakistan, except major part of upper and lower Indus Plains, has numerous hill

torrent which arc shown in Fig. 1.5.

9

6.

,

•..•

ARABIA •• Sf A

Source: Master Feasibility Srudies for Flood Management of Hill-Torrents of Pakistan. NESPAK, November 1998

Fig. 1.5: Major Hill-Torrent. of Pakistan

1.7 Demographic Features In 1947 32.5 million people lived in Pakistan. According to the first census in 1951, the population of

Pakistan stood at 33.7 million. This ro e to 133.61 million in the census conducted during 1998.

According to National Institute of Population Studies, Islamabad. in 2005, the population of Pakistan

was 153.45 million. The Province-wise population, land area, percentage distribution and population

den ity, based on 2005 are shown in Table 1.3.

10

Table 13: Population in thousands

Source: Ministry of Po pula lion Welfare, Govt. of Pakistan (Census: 2005)

(*): Federally Administered Tribal Area

Punjab, NWFP and Sindh are the most thickly populated provinces. The province of Balochistan,

though constitutes around 44 % of the total area of Pakistan, has the lowest population density.

1.8 Agriculture in Pakistan

Pakistan is an agro-based country where agriculture contributes around 24 percent of GOP generates

about 50 percent of employment and is a major source of livelihood for more than 60 percent of people

living in the rural areas. The total geographical area of Pakistan is 79.6 million hectares but only about

59 million hectares arc reported as utilized. Out of thi total reported area, 37% was cultivated and the

rest was reported as either not available for cultivation (above 40%) or culrurable waste (15%) or forest

area (6%).

Most part of the country is classified as arid to semi-arid where rainfall is not sufficient for crop

cultivation. As such irrigated cultivation is the most prominent feature of our agriculture. Ten years

average stati tics (1990/91-1999/2000) indicate that out of the total cultivated area of 21.60 million

hectare, 80% (17.28 million hectares) is irrigated area, while the remaining 20% relics on rainfall.

Wheat, rice, cotton, sugarcane and maize are the major irrigated crops of Pakistan. Over the period

from 2001-2007, the cultivated area under the major food grainslcrop have increased by around 9%.

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Province Area Total Area Population Population Population Density 1

Sq. Km (%) (2005) (%) Sq.Km

Pakistan 796095 100.0 153,450 100.00 193

NWFP 74521 9.4 20,930 13.64 281 Punjab 205344 25.8 84,810 55.27 413

Sindh 140914 17.7 35,260 22.98 250 Balochistan 347190 43.6 7,820 5.10 23 FATA* 27220 3.4 3,550 2.31 130 Islamabad 906 0.1 1,080 0.70 1192

Table 1.4: Area of Important Crops (Thousand Hectares)

Table 1.5: Production of Important Crops (Thousand Tonnes)

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Table 1.6: Yield / Hectare of Major Crops (Kg/Hectares)

Crops 2002-03 2003-04 2004-05 2005-06 2006-07

Wheat 2,388 2,373 2,586 2,519 2,716

Rice 2,013 1,970 1,994 2,116 2,107

Bajra 542 508 563 501 472

Jowar 598 606 604 602 616

Maize 1,856 2,003 2,848 2,985 3,036

Barely 926 961 989 978 989

Gram 701 622 793 466 797

Sugarcane * 47.3 49.7 48.9 49.2 53.2

Rapeseed, Mustard & Canola 8361 850 840 797 831

Cotton 622 572 760 714 711 Potatoes * 16.8 17.6 18.1 13.3 19.4

Onion* 13.2 13.3 13.8 13.8 13.9

Chillies 1,737 1,714 1,837 1,892 1,489 Tobacco 1,872 1,870 1,989 2,018 2,020

* = Yield in tonnes per hectare.

Note: (i) 1 hectare = 2.4711 acres (ii) One cotton bale = 375 lbs or 170.09 kgs.

Source: Federal Bureau of Statistics, 2008.

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Chapter 2

Climate Data Monitoring System in Pakistan 2.1 Agency Responsible for Weather and Climate Data Monitoring

Pakistan Meteorological Department (PMD) is the main agency responsible for monitoring the

weather and climate related activities in the country. PMD is both a scientific and a service

department. It is responsible for providing meteorological services throughout Pakistan to a wide

variety of users. Besides routine meteorological services such as data collection, its processing,

archiving and day to day weather forecasts and their dissemination, the department also deals with

fields like Agro-meteorology, Hydro-meteorology (flood forecasting), Astronomy and

Astrophysics, Seismology, Geomagnetism, Ozone Monitoring, Weather Modification, Drought

Monitoring etc. All types of meteorological disasters (tropical storms, severe cyclonic storms,

heavy rains, thunderstorms and tornadoes etc.), hydro-meteorological disasters (floods, droughts

etc.) and geophysical disasters (earthquakes, ozone depletion, ionospheric disturbances, magnetic

storms etc.) are monitored by PMD. Climatic Normals of Pakistan for the three 30-year periods:

1931-60, 1961-90 and 1971-2000 are available with the department in the published form.

Monthly data of all the meteorological stations are also available with the department in the

digitized form. Hourly and daily data, yet to be fully digitized, are also available in the archives

ofPMD.

2.2 Network of Meteorological Stations

The network of Meteorological stations is shown in Fig 2.1. The network, according to WMO

requirements, is not adequate and needs to be further augmented, particularly in the mountainous

north and in the southern half of the country. However, the department is actively on way to

strengthening the present network by establishing additional stations. In addition, a network of

agro-meteorological observatories is also functional where soil temperature, soil moisture, solar

radiation, wind speed & direction in crop atmospheres are recorded in addition to other

meteorological parameters. Agromet network of Pakistan is shown in Fig. 2.2.

14

7. Network of Meteorological Stations in Pakistan

Source: Pakistan Meteorological Department

Fig 2.1: Network of Meteorological Stations in Pakistan

15

8. 9.

Fig. 2.2: Agromet Network of Pakistan

2.3 Meteorological Parameters Recorded

Meteorological parameters recorded at different meteorological stations are: Air Pressure (Station

level and pressure reduced to mean sea level), Ambient Air Temperature (Dry Bulb, Wet Bulb, Dew

Point, Maximum and Minimum), Precipitation (Daily and monthly totals, Mean number of rainy days,

Heaviest falls in 24 hours, Wettest and Driest precipitation amounts), Wind speed & direction,

Sunshine hours, Visibility, Cloud type and amount, atmospheric phenomena like haze, fog, dust

storm, snow, thunderstorms etc. These are usually recorded at all synoptic hours usually at one or three

hourly intervals as set by the World Meteorological Organization (WMO) standards fixed for the type

of station established. Solar

16

radiation is also recorded at six stations namely, Peshawar, Islamabad, Lahore, Multan, Quetta and

Karachi. The network of solar radiation stations falls within the technical control of Geophysical Centre, Quetta.

2.4 Inventory of Meteorological Stations The list of Meteorological stations used for this report, with their WMO Index numbers, geographical

coordinates, elevations in meters and the period for which climate data is available are listed

alphabetically in Table 2.1 and shown in Appendix I.

2.5 Global Climate Observing System (GCOS)

Pakistan contributes the data of its six stations at Parachinar, Lahore, Dalbandin, Hyderabad, Pasni,

Zhob to GCOS (Global Climate Observing System) surface and upper-air networks:

GSN (Global Surface Network) and GUAN (Global Upper Air Network) established in 1992 to ensure

that the observations and information needed to address climate-related issues are obtained and made

available to all potential users. GCOS is co-sponsored by World Meteorological Organization (WMO),

the Intergovernmental Oceanographic Commission (lOC), the United Nations Environmental

Programme (UNEP) and the International Council of UNESCO (lCU).

2.6 Climatic Normals published by PMD Following the criteria of World Meteorological Organization (WMO), PMD has so far published three

Climatic Normals for the 30-year periods 1931-60, 1961-90 & 1971-2000:

2.6.1 1931-1960

The publication comprises the normals (i.e. means and extremes) for the period 1931-1960 for 61

Meteorological stations distributed throughout the country. Practically these are spread over 54 sites as

some sites has more than one station. The data is scanty and is characterized by a number of missing

values.

2.6.2 1961-1990

Eighteen stations were closed during the period 1931-60 and some fifteen new stations were added

during the period 1961-90. Quality and quantity of data, when compared to the 1931-60

17

normal period, is much better. Frequency of missing value' is less. The list of the network stations during J

931-60 and 1961·90 is shown in able 2.2 placed in Appendix II.

2.6.3 1971-2000

This is the updated version of the 30-year normal data of 1961-90 where the first lO·year data is replaced by

(he last Iu-years data of 1991 to 2000. Stations are the same.

2.7 Newly Established Meteorological Stations

With the enhanced aviational, agricultural, flood and drought management requirement. some new

meteorological stations have, over the recent years, been established. Establishment of new meteorological

stations is a continued process and PMD is actively engaged in the further strengthening of its network. The

pace of work has tremendously enhanced in the recent years, The newly added stations include: Babusar,

Chakwal D.I, Khan Jhang, Kalam Malam Jabba and Mandi Bahauddin,

2.8 Adequacys of Network Stations

An exercise was carried out to see whether the number of network stations with regard to precipitation is

adequate or otherwise, Analysis of 1961-90 normal precipitation data revealed that some 60 more stations

were additionally required to make it hare adequate.

2.9 Additional Data Generating Sources in the Department

Pakistan Meteorological Department has some other data information ources. These arc mentioned in the

subsequent paragraphs:

2.9.1 RADAR etwork

"

Upper catchments of the Indus River and its tributaries mostly lie across the border in India and Indian held

Kashmir, where ground based rainfall measuring stations arc neither available nor can have their

installation po sible, The radar network serves as the only mainstay for the real time observation of weather

sy tems and quantification of the rainfall mea urements in the se catchments for the purpose of weather and

flood forecasting. PMD has established a network of four 5.7 em wavelength weather radars at Islamabad,

D.l. Khan, Rahim Yar Khan and Karachi.

18

All these four radars are inter-connected through fibre optic and data is communicated to all airports and

weather forecasting centres on five to thirty minutes intervals.

In addition, three weather radars one of 5.7 em wavelength and the other two of 10 em wavelength are

located rc pectivcly at Sialkot, Lahore and angla (Recently installed in 2008) to measure quantitatively

the rainfall in the upper catchments of rivers up to Jhelurn. TIle data is used mainly for flood forecasting at

the rim stations of the rivers and for their downstream routing. The radar data i also helpful in the

forecasting of urban storm flooding to help reduce their adverse effect in the cities. The weather radar

network is shown in Fig. 2.3

Sourcc: Pakistan Meteorological Depertmenr

RADAR NETWORK OF PMD

Area covered by Doppler radar at Lahore

Fig. 2.3: The Weather Radar Network in Pakistan

19

10.

2.9.2 Satellite Ground Receiving Stations HRPT (High Resolution Picture Transmission) systems are installed at Islamabad and Quetta. These

receive satellite images from the polar orbiting and geo-stationary satellites and are linked to the PMD

website.

2.9.3 Wind Power Potential Survey in Pakistan Paki tan Meteorological Department (PMD) ha for the last few years, been working on a research

project titled: "Wind Power Potential Survey in Pakistan". More than two years wind data has been

collected and analyzed at about 45 locations along the Sindh-Balochistan Coast. Detailed reports

containing data collected at these stations and analysis are available in the published form. Parameters

recorded at these stations include wind speed at 10 and 30 meter heights and extrapolated wind speed at

50 meter height. As a second phase of the project sorn 42 wind mapping stations have been installed in

the northern Pakistan, in particular ill the northern mountainous areas since early 2007. The network of

wind-mapping stations is hown in Figs. 2.4 2.5 & 2.6.

Arabian Sea

Source : Pakistan Meteorological Department Fig. 2.4: Wind-mapping station along Balochistan Coast

20

11.

Arabian Sea

b7° Sourcc: Paki Ian tctccrologicat Department

Fig. 2.5: Wind-mapping station along Sindh Coast

21

Sorce: Pakistan Meteorological Department

Fig. 2.6: Wind-mapping stations in orthern Pakistan

The stations located along Balochistan and Sindh Coasts include:

Aghore, Basol, Bella, Gaddani Gawadar Hoshab Hub Chowki, Jiwani, Liari, Makela, Managi Mand,

asirabad, Nelunt, Ormara, OthaJ, Pasni, Phore, Pishukhan Ramra Turnp Turbat Winder Badin Baghan,

Chuhar, Jarnali, Gharo, Golarchi Hawks Bay, Hyderabad, Jati,

22

Kadhan, Karachi, Kati Bandar, Matli Mirpur Sakro, Nooriabad Sajawal, Shah Bandar Talhar, Thanu

Bula Khan.

The stations located in the orthem areas of the country include:

Astore, Aliabad (Hunza), Ayune, Bahrain, Bamborait (Kalash), Barapayan (Khaplu), Besharn Qila

Bunji, Chila • Chitral city, Danakool Chakcsir, Dargai, Dir, Drosh Fatehpur (Madyan Road), Garam

Chashma (Chitral), GilGJt, Gupis, Kaghozi ( hitral), Kalam Khawazakhaila (Swat) Khudabad (Sost)

Khungi payan (Dir), Lempiapatian Sheed (AJK) , Lorrarniana (Jhyber Agency), Malamjabba Mastuj,

Mirkhani (Chitral), oorti Pabari, Nizampur (Nowshchra) Passu (Hunza), Pedar, Bagh (AJK), Reshan

(Chitral), Ramatkoore, Mitai (Mohmand Agency) Sermik (Skardu) Shaghore (Chitral), Shahida Sir

Batarra (Buneer), Shigar ( orthem Area), Tarbela (Haripur), arsak (peshawar).

2.9.4 Drought/Environment Monitoring and Early Warning Centre National Centre for "Drought/Environment Monitoring and Early Warning" has been set-up very

recently in Islamabad. The basic intention is to identify the drought vulnerable areas within the country

issue early warnings for these areas and study their likely impacts on different socio-economic sectors

and advise concerned authorities for appropriate adaptation measures.

Under this project a number of data acquisition equipments are being installed in different parts of the

country. These include 50 Automatic Weather Stations, 500 rain gauge stations and 20 soil moisture

and under ground water level monitoring probes. Drought monitoring network is shown in Fig. 2.7.

23

12. Sourcc: Pakistan Meteorological Department

Fig. 2.7: Drought/Environment Monitoring & Early Warning C ntrcs

24

Chapter 3

Temperature Regime over Pakistan

3.1 Introduction

Temperature is an independent variable among the climatic elements. Variations in temperature cause

corresponding changes in the pres ure distribution and consequently in wind direction and its intensity

which in turn control atmospheric humidity, formation of clouds and condensation proces es etc.

Directly or indirectly, temperature governs all other weather elements in this way. Among the climatic

elements, there is none of such vital importance to biosphere as temperature and there is none which

exercises so profound a control over human distributions.

Temperature thus holds a key position in the climatic studies and requires, as a fir t step, the drawl of a

picture for the spatial distribution of temperature over the country.

3.2 Topics covered The chapter covers the following topics:

3.2.1 Station-wise monthly temperature (Mean, Maximum and Minimum) variations

during the periods: 1961-1990 and 1951-2000.

3.2.2 Station-wise easonal temperature variations (1961-90)

3.2.3 Annual range oftemperatures Extreme Maximum and dinimum Temperatures 3.2.4 Annual

and seasonal temperature (Mean, Maximum and Minimum) distribution.

3.2.1 Station-wise Monthly Temperature Variations Some 48 climatological stations are used to study the actual temperature conditions for all the months

(January to December). Consequently a set of 48 composite bars for all the stations have been prepared

usi.ng the normal data of 1961-90 and of 1951-2000 or for the period data is available. June is usually

the wannest month except in the Greater Himalayan region where all the nine (09) stations show July

as the warmest month. Some other station in the Balochistan Plateau have the wannest month as July.

Besides that Saidu Sharif, Parachinar and Quetta are also warmest in July. The month of January is the

coldest month all over Pakistan.

25

Pakistan has a latitudinal extension from 24° to 37°C. On June 21 or 22 the vertical sun rays strike 23.5°

(Tropic of Cancer), June 21 or 22 the surnrner solstice is thus the first official day of summer in

Pakistan. June and Ju1y thus constitute the warmest months over Pakistan. On the other hand Dec 21 or

22 is the first official day of winter at the Tropic of Cancer and the month of January constitute the

coldest month over Pakistan Monthly temperature values in the bar [ann for the two periods 1961-)

990 and 1951-2000 are shown in Figures 3.1 to 3.48 along with their temperature values. Figs. 3.3 to

3.48 are placed in Appendix III.

Station-wise Monthly Temperature Variations in °C

Fig. 3.1: Monthly Temperature Variation at Astor

Fig 3.2: Monthly Temperature Variation at Badin

26

3.2.2 Station-wise Temperature (Mean, Max and Min) Variations Using the 30-year normal value of 1961-90, the temperature (mean maximum and minimum)

value on annual and seasonal bar are shown in (he form of bar graph in Fig . 3.49 to 3.57 along

with their tabulated values in Tables 3.1 to 3.9.

Table 3.1 Fig. 3.49

27

13. Table 3.2

Table 3.3

Fig. 3.50

Fig. 3.51

28

14. Table 3.4

Table 3.5

Fig. 3.52

Fig. 3.53

29

30

3.2.3 Conclusions

Temperature (mean, maximum & minimum) are highest in the southern parts of the country in

the Sindh Province and the adjoining areas of Balochistan and outhern Punjab. west

temperatures usually center around Astore in the Greater Himalayan region in both the season .

• ean maximum monsoon temperature are a high as 425.˚C around Sibbi and mean minimum winter

temperatures are as Iow as -4.6°C around A lore.

3.3 Annual Range of Temperature

The annual range of temperature for a given location is calculated from the difference between the

average temperature of the warrne t and the coldest month. These are hown in Table 3.10 and Fig. 3.58.

The extreme maximum and minimum temperatures based on (he 3D-year normal period (1961-1990)

are shown in Figs. 3.59 and 3.60.

32

33

3.3.1 Extreme Temperatures (Maximum & Minimum) during 1961 ~90 are shown graphically in Figs. 3.59 and 3.60

Fig. 3.59: Extreme Maximum Temperatures (1961-1990)

Fig. 3.60: Extreme Minimum Temperatures (1961-1990)

3.3.2 Conclusions

1. The annual temperature ranges vary from about 12 to 27°C. 2. The annual range of temperature is minimum in the coastal areas along the Arabian

Sea and maximum in the mountainous north in the Greater Himalayan and in the

desert regions.

34

3. The extreme minimum temperature went a low as -21°C at Astor on Feb 9, 1974.

4. 52°C is the highest maximum temperature recorded at Sibbi on 12 June, 1979. 53°C.

however, remains as the highest maximum temperature recorded at Jacobabad on 12

June, 1919.

3.4 Temperature Distribution (1951-2000)

Temperature distribution using the monthly data for 1951-2000 on annual and easonal basis for

mean, maximum and minimum temperatur js shown in contour form in Figs. 3.6J to 3.75 and in

tabular form in Tables 3.14 - 3.16 (Appendix. IV). ean values of temperature (mean, maximum &

minimum) for different zone are hown in Tables 3.11, 3.12 and 3.13. The purpose is to provide the

base line patterns for the climate changes worked out over the above period (chapter 5).

Spatial Mean Temperature Distribution

24

35

34

32

30

28

26

Fig. 3.61:M ean Annual Temperature in °C (1951-2000)

35

15. Fig. 3.62: Mean Monsoon Temperature in ˚C (1951-2000)

Fig. 3.63: Mean Winter Temperature in °C (19-1-2000)

36

16. 17.

30

26

36

32

28

24

62

64

86

68

70

72

74

76

Fig. 3.64: Mean (Apr-May) Temperature in °C (1951-2000)

3o

28

36

34

32

62

64

66

6tl 70

7d

Fig. 3.65: lean (Oct-N ov) Temperature in °C (1951-2000)

37

Table 3.11: Summary of Zone-wise Annual & easonal Mean Temperature (˚C) (1951-2000)

Annual Monsoon Winter Apr- Oct-Nov

Region Average Average Average May Average

Average

l.Zone- 1(a) 15.2 25.1 5.3 17.2 12.9

Greater Himalayas Zone-l(b) Sub-montane Region 20.1 27.4 11.8 23.5 18.4

and monsoon dominated Zone-II 20.8 29.0 11.8 24.0 19.0 Western Highlands

Zone-III 24.8 32.7 15.7 29.4 22.7

Central and Southern Punjab Zone-IV 26.8 33.0 18.9 31.9 25.2

Lower Indus Plain Zone V(a) : Balochi. tan Plateau

(Northern) (Sulairnan & 20.9 29.0 12.2 24.7 18.6 Kirthar Ranges)

Zone V(b): Balochistan Plateau 23.1 31.9 13.7 27.1 19.9 (Western)

Zone-VI Coa tal Belt 26.0 29.9 20.7 29.4 25.8

38

18. 19. Spatial Mean Maximum Temperature Distribution

6,2 64

66

68

70 72 74 76

Fig. 3.66: Annual Mean aximum Temperature in °C (1951-~OOO)

32

28

36

34

30

2~

62 66

68 70

12

74

76

Fig. 3.67: Mean 1aximum Mon oon Temperature in °C (l951-2000)

39

20. 21.

Fig. 3.68: Mean Maximum Winter Temperature in °C (1951-2000)

22.

56

32

30

28

26

24

62

66 68

70 72 71t. 76

Fig. 3.70: Mean Maximum (Oct- ov) Temperature in °C (195 1-2000)

Table 3.12: Summary of Zone-wi e Annual & Seasonal Mean Maximum Temperature ˚C) (1951-2000)

Annual Monsoon Winter Apr- Oct-Nov

Region Average Average Average May Average Averaze

Zone-l(a) 21.7 32.4 10.7 23.8 20.4

Greater Himalaya Zone-l(b)

Sub-montane Region 26.4 33.1 18.0 30.5 25.9 and monsoon dominated

Zone-II 27.2 35.0 18.1 30.8 26.1

'Western Highlands I

Zone-III 32.2 38.7 23.5 37.5 31.2

Central and Southern Punjab Zone-IV

34.6 39.3 27.3 40.7 33.8 Lower Indus Plains

Zone-V (a) : Balochistan Plateau ( Northern) (Sulaiman & 28.5 36.2 19.6 32.4 27.3

Kirthar Ranees) Zone V(b): Balochistan Plateau

31.2 40.0 21.3 35.1 28.8 Western)

Zone-VI Coastal Belt 31.6 33.5 27.5 35.3 32.6

41

23. Spatial Mean Minimum Temperature Distribution (1951-2000)

36

32

30

20

26

24

Fig. 3.71: Annual Mean Minimum Temperature in ˚C (1951-2000)

Fig. 3.72: Mean Minimum Mon. con Temperature in "C (1951-2000)

42

30

36

34

32

28

26

24

Fig. 3.73: Mean Minimum Winter Temperature in °C (1951-2000)

26

36

34

32

30

28

24

62

64

66

68

70 72 74 76

Fig. 3.74: Mean Minimum (Apr-May) Temperature in °C (1951-2000)

43

Fig. 3.75: Mean Minimum (Oct- ov) Temperature in °C (1951-2000)

Table 3.13: Summary of Zone-wi e Annual & Seasonal Mean Minimum Temperature (˚C) (1951-2000)

Region Annual Monsoon Winter Apl'.:May Oct--Nov

Average Average Average Average Average

Zone-lea) 8.6 17.9 -0.2 10.6 5.6 Greater Himalaya

Zone-l(b) Sub-montane Region 13.7 21.6 5.5 16.6 11.0

and monsoon dominated Zone-II

14.4 23.2 -.5 17.3 12.0 Wcstern Highlands

Zone-III 17.5 26.8 7.9 21.3 14.3

Central and Southern Punjab Zone-IV

19.0 26.7 10.4 23.1 16.6 Lower Indus Plain

Zone V(a) : Balochistan Plateau Northem) (Sulaiman & 13.3 21.8 4.8 17.0 9.9

Kirthar Ranges) Zone V(b): Balochistan Plateau 15.0 23.8 6.1 19.0 11.0

(Western)

Zone- VI Coastal Belt 20.4 26.3 13.9 23.4 18.9

3.5 Conclusions

The normal picture drawn from the the tabular value and grapb show at the lower Indus plains, the

Sindh Province and adjoining Southem Punjab and coastal areas are the warmest and temperature'

remain around 25°C and above during different seasons except during winter when these are

usually below 20°C. Contrary to the above, stations in the orthern Mountain region show mueh

lower temperatures in all the seasons except during the monsoon period when these exceed 25°C.

The temperature range in the e two extremes is around 18°C. Average temperatures during the

men oon period remain above 25°C in all the zones with highest in the Lower Indus Plain.

45

Chapter 4

Rainfall Distribution over Pakistan

4.1 Introduction

Next to temperature, rainfall occupie: an important position in the list of climatic elements. It has an

exten ive use in tile water related studies such as water resource and their management, water related

disasters and their mitigation, water balance studies and the studies related to the usc of water for

agricultural production and power generation etc. The rainfall distribution and consequently the water

generated due to this i a pre-requisite need for the prosperity of a country more 0 for Pakistan which is

basically an agrarian country.

Pakistan is generally an arid to semi arid country with a humid hell along the nib-moutane regions on the

southern slopes of Himalayan Mountains where the annual total rainfall can be as high as 70 inche: (-

1800 mrn) at Murree and a. Iowa 1.5 inches (- 35mm) around Nokkundi in the hyper arid regions of

Balochi tan Province. Maximum rainfall over the country occurs during the monsoon period (June to

September). The monsoonal systems penetrate the country either from the Arabian Sea or from the Bay

of Bengal. The monsoonal current developing as tropical depressions in the Bay of Bengal, moving ill a

west, northwesterly direction across the Gangetic Plains over India, at times reach the Indus Plains. By

the time they reach there, their intensity decreases considerably. However, at times, these depressions

juxtapose with the strong we stern disturbances or get accentuated due the outhwesterly currents from

the Arabian Sea and cause heavy rain in the .ubmontane region' and other part of the country depending

upon the synoptic conditions. Similarly monsoon ystcms/depressions are facilitated to flow

uninterrupted to the submontane region by the strong pres: tire gradient between the sea and the

adjoining continental area. A semi permanent thermal low develop over .ome parts of Baloehi tan and

adjoining Sindh and southern Punjab during the summer months (Apr-Jun) which provide the necessary

pressure gradient force between the Arabian sea and these adjoining land masses. Winter rain are

brought by the western di turbance and while crossing the country as primary waves/disturbances within

the latitude 30-60° shed out their moisture in the upper parts of the country. At limes, they develop their

secondarie and penetrate deep into lower latitudes and get accentuated by the moi ture from the Arabian

Sea and bring rains in most parts of the country. The rainfall distribution pattern are discus .ed in the

subsequent paragraph. :

46

4.2 Station-wise Monthly Precipibltion Patterns (1961-90 & 1951-2000) Monthly

values of total precipitation for the 30-year normal period 1961-90 and for the period 1951-2000

(or for the period data is available) are plotted as bar graphs and shown in Figs. 4.1 to 4.48. Figures

4.3-4.48 are placed in Appendix. The rainfall is maximum either in the monsoon (June to

Septernber) or in the winter season (December to March) depending upon the location. November

seen to be the month of minimum precipitation allover Pakistan. October then comes next. Winter

ea on u sually extend up to April or even up to May in the rnountainou: north particularly in the

Greater Himalayan region above 35°N. The weighted monsoon (June to September) precipitation

over the country, as a whole, is almost twice as high as the winter (December to March)

precipitation. However, in the Punjab Province, the upper part of which i mostly mon oon

dominated, the weighted monsoon ram compared to winter rain' are around three times higher.

Station-wise Rainfall Patterns

Fig. 4.1: Rainfall pattern at Astor

Fig. 4.2: Rainfall pattern at Badin

4.3 Wcighted Precipitation over the Country

Estimated Weighted Precipitation (mm) using Theissan polygon method over Pakistan and its

Province'based on the 30 year normal value of 1961-90 is given in Table 4.1 and graphically rcprc

cnted in Fig 4.49.

Table 4.1: Estimared Weighted Precipitation (mm)

Months Pakistan Balochistan NWFP Punjab Sindh Jan 17.0 17.8 39.5 15.0 1.9

Feb 22.5 18.6 61.0 22.4 4.6 Mar 31.0 22.0 95.3 32.0 5.1 Apr 19.7 11.9 66.7 20.7 3.1 May 13.2 8.2 39.8 15.8 2.4 Jun 14.0 5.4 27.7 24.6 10.0

Jul 62.5 28.6 95.4 108.4 56.9 Aug 55.4 23.0 94.0 93.6 52.4 Sep 19.5 7.2 35.8 33.7 18.2 Oct 5.7 2.1 21.1 6.4 2.4

Nov 4.9 2.7 16.6 4.9 2.0 Dec 12.4 10.9 33.0 11.7 2.6 Sum 277.8 158.4 625.9 389.2 161.6 Mean 23.2 13.2 52.2 32.4 13.5

Source: Pakistan Meteorological Deparrment

Fig. 4.49: E timated Weighted Precipitation over Pakistan and it. Provinces (1961 -90)

48

4.4 Station-wise Total Annual and Seasonal Precipitation (1961-90)

These are shown in Figs. 4.50-4.52 and in Table' 4.2 lO 4.4. On annual basis Murree, a place in the

sub-montane region, gets the highest rainfall where as okkundi, a station in the deserts of Western

Balochistan receives the minimum amount of precipitation. Sununer monsoons again bring highest

rainmfall over Murree and lowest over Nokkundi. The winter rain' are highest in Dir, a station in the

Greater Himalayan region and lowest over Moenjo Dam, a station in the lower Indus Plains.

Table 4.2

49

4.4.1 Heaviest Rainfall in 24 Hours (1961-1990)

This is shown in Fig. 4.53. These are ignificantly high in the monsoon dominated region and in the

upper and lower Indus Plain whereas insignificantly low in the Greater Himalayan region and in

the desert areas of Balochistan, Occurrence of such falls is highly variable. Islamabad, the Capital

of Pakistan received, 620 mm rainfall in just 10 hours on 23 July> 2001.

Fig. 4.53: Heaviest Rainfall in 24 Hours (1961-90)

4.5 Station-wise Annual and Seasonal Precipitation Patterns (1951-2000) These are

presented in Table 4.5 (Appendix) and show the mean totals of precipitation (mm) on annual and

seasonal basis for all stations in. different zones.

4.5.1 Zone-wise Annual & Seasonal Average Precipitation (1951-2000)

These are consolidated for differ nt zones in Table 4.6. Annual and seasonal precipitation totals

in millimeters are shown in contour form in Figs. 4.54 to 4.58. ."

51

24.

Table 4.6: Summary of the Zone-wise annual & seasonal Average Precipitation (mm) (1951-2000)

Region Annual Moonsoon Winter Apr-May Oct-Nov

Average Average Average Average Average

Zone-l(a) 436.3 99.7 185.1 l16.6 36.5 Greater Himalayas

Zone-l (b) Sub-montane Region 1272.9 710.4 352.2 146.1 68.2

and monsoon dominated Zone-II 571.1 238.6 201.5 97.8 34.5

Western Highlands Zone-III 286.9 189.1 54.7 32.1 10.8

Central and Southern Punjab Zone-IV 148.7 120.4 15.1 6.3 5.0

Lower Indus Plain Zone-V (a)

Balochistan Plateau (Northern) 246.0 112.5 92.2 32.2 9.6 (Sulaiman & Kirthar Ranges)

V(b) 74.6 13.4 50.5 8.1 3.1 Balochistan Plateau (Western)

Zone- V Coastal Belt 155.7 89.3 55.9 4.9 5.9

Spatial Annual & Seasonal Precipitation (mm) Distribution (1951-2000)

52

25.

Fig 4.54: Annual Total Precipitation (mm)

Fig 4.55: Mon oon Total Precipiraticn (mm)

Fig 4.56: Winter" Total Precipitation (mm)

53

26. 27.

54

4.6 Conclusions

Rains compared to other region are highest in the sub-montane region in all the seasons and lowest in

the Balochisian Plateau in Zone V (b). Western Highland then come next to the sub-montane region

receiving significant rain. These are brought both by the monsoon and winter y terns. All the zones

receive minimum rains during Oct- nov, the Post monsoon sea on in Pakistan. The Upper Indu: Plains

(Zone III) receive comparatively more rains than Lower Indus Plain. (Zone IV).

55

Chapter 5

Past Climate Changes in Pakistan

5.1 Introduction

The chapter focuses on the assessment of past climate changes in monthly Temperature (Mean Maximum &

Minimum) and Precipitation using tile data of 54 stations for a maximum period of 50 years (1951-2000) or as

available in Table 2.1 (Chapter 2).

5.2 Data and Methodology

Trend analy is-u ing the least quare method has been done and changes have been worked out on annual and

sea 'onal basis. Their ignificance at 90, 95 & 99% confidence levels arc also worked out. Changes over the

previous century (1901-2000) have also been worked out for mean annual temperature and total annual

precipitation using RU TS 2.0 observed data available at 0.5 degree grids for Pakistan.

The chapter al 0 includes the Extreme Trend analysis carried out on monthly basis in temperature and

precipitation and number of tations showing increasing or decreasing trend for each zone are then computed

and results drawn. The methodology employed in computing the extreme values followed the following

steps:

(a) Extreme values in the Temperature (maximum & minimum) and Precipitation falling above and below 1

standard deviation and for precipitation falling above 90tl) percentile are worked out for all the

tations and for all the months eparately over the entire 50 year period.

(b) Values falling above 1 standard deviation (0) in case of maximum temperature and below 1 standard

deviation (<1) in case of minimum temperature for all months are then added up to find yearly totals

for each station and time series data are then generated for all stations. Similarly time series data for

all stations are generated for precipitation falling above 90th percentile.

(c) Trend analysis is then carried out and number of stations showing increasing or decreasing trend for both

the hot and cold ca es in case of temperature and wet and dry cases in case of precipitation are

identified.

56

5.3 Trend graphs showing significant changes in Mean Temperature (1951-2000)

Some Sample Trend Graphs showing significant changes at 90, 95 & 99 % are shown in Figs 5.1 (a-h)

57

28. 29. 30.

31. 5.3.1 Mean Temperature Trends (1951-2000)

Mean temperature trend change. for the period 1951-2000 on annual and seasonal basis for individual stations are shown in Tables 5.1 to 5.5 (Appendix VII)

5.3.2 Mean temperature trends (1951-2000) are presented in contour form in Fig .. 5.2 (a-c). The purpose is to help interpolate the changes for other locations.

62 64 76

Fig. 5.2 a: Annual Mean Temperature Trends (˚C)

Fig. 5.2 b: Monsoon Mean Temperature Trends (˚C)

32.

Fig. 5.2 c: Winter Mean Temperature Trends (˚C)

Fig. 5.2 d: (Apr-May) Mean Temperature Trends (˚C)

60

33.

36

3d

32

30

28

26

62 64 66 68 70 72 74

Fig. 5.2 c: (Oct-Nov) Mean Temperature Trends (˚C)

61

34. 35. 36. 5.3.3 Graphical Presentation of Zone-wise lean Temperature Trends (1951-2000)

Mean temperature trend changes are shown for djfferent zone :Fig 5.3(a-e)

JIN~-------r---------~-:::::;

lIN

'<~tk'~'-------::EH-:::f------::6&::---'----:C7:l'-f ----~71<::--' 1.17 OM

.g. 5.3 a: Annual Mean Temperature Trend in ˚C (1951-2000)

3tN

JIll'

Fig. 5.3 b: Monsoon Mean Temperature Trend in ˚C (1951-2000)

62

37. 38.

Fig. 5.3 d: Winter Mean Temperature Trend in °C (1951-2000)

63

39.

21N

'5N

2ml------~----- WE

o.;~

Fig. 5.3 e: (Oct-Nov) Mean Temperature Trend ill °C (1951-2000)

64

2m

5.3.4 Summary of Zone-wise Mean Temperature Trends (1951-2000)

Table 5.6: Zone-wise Summary of Mean Temperature Trends (˚C) (1951-2000)

5.4 Mean Temperature Trend 190'1-2000 for Pakistan with CRU Data

The CRU (Climatic Re earch nit, UK) data developed by Dr. Tim Mitchell

(http://www.em.uea.ac.uk/~timm/index.html) for the whole globe on country basis has been

extracted for Pakistan and the trend is worked out (Fig. 5.4). The CRU data is an assimilation of the

observational data from meteorological stations onto 0.5° latitude by 0.5° longitude covering the land

surface of the earth (New et, al; 1999-2000). In the new data-set, the gridded data arc transformed into

'country' averages by calculating the weighted mean of the constituent grid boxes of eaeh country. The

change of O.6°C over Pakistan is in accordance with the inerea e in the global surface temperature by

0.6° over the previous century.

65

Fig. 5.4: CRU data: Mean Temperature (˚C) Trend 1901-2000 for Pakistan

5.5 Discussion on Mean Temperature Trend Changes

All the zones how decreasing trend during the monsoon period except Zone v(a) & v(b): Balochistan Plateau where there is an increasing trend.

Out of 54 stations 35 have shown decreasing trend during Monsoon. This trend is significant at 23 stations at 90 95 & 99 % levels.

Winter temperatures show an increasing trend in Greater Himalayan region and the summer (Apr-May) temperatures show increasing trend in all the regions.

• Balochistan Plateau shows warming trend in all the seasons.

• Coastal areas show increasing trend in all seasons except during the monsoon season.

Temperatures have fallen over West em Highlands and lower Indus Plains during winter, elsewhere there is an increa ing trend.

Temperatures during winter show higher trends in the desert regions and coastal regions except around Pasni and Ormara.

Out of 54 stations, 41 have shown increasing trend during Apr-May. Out of these 13 stations show increasing trends at 90 95 & 99 % significance level.

Temperatures show increa ing trend in all the regions except in the Greater imalayas and Western Highland during Oct-Nov.

The temperature change over the last century (1901-2000) over Pakistan using the CRU (Climate Research unit, UK) is found out to be O.6°C. This tallies with the global rise in temperature over the-previous century.

66

40. 41. 42. 43. 44.

5.6: Trend graphs showing significant changes in Mean Maximum Temperature (1951-2000)

Some Sample Trend Graphs showing significant changes at 90, 95 & 99% are shown in Figs. 5.5 (a-h).

45. 5.6.1 Mean Maximum Temperature Trends (1951-2000)

Trend changes in mean maximum temperature on annual and seasonal basis are shown for individual stations ill Tables 5.7 to 5.11 in Appendix VITI.

5.6.2 Mean maximum temperature trends for 1951-2000 are presented in contour form in Figs. 5.6(a-e). The purpose is to help interpolate the changes for other locations.

Fig. 5.6 a: Annual Mean Maximum Temperature Trends (˚C)

Fig. 5.6 b: Monsoon Mean Maximum temperature Trend (˚C)

69

Fig. 5.6 c: Winter Mean Maximum Temperature Trends (˚C)

Fig. 5.6 d: (Apr-May) Mean Maximum Temperature Trends (˚C)

70

46. Fig~. 5.6 c: (Oct- Nov) Mean Maximum Temperature Trends (˚C)

5.6.3 Graphical Presentation of Zone-wise Mean Temperature Trends (1951-2000) Mean

maximum temperature trend changes are shown for different zones in Figs. 5.7 (a-e).

Fig. 5.7 a: Annual Mean Maximum Temperature Trend °C (1951-2000)

71

47. 48.

Fig. 5.7 b: Monsoon Mean Iaximum Temperature Trend °C (l951-2000)

0.10

Fig. 5.7 c: Winter Mean Maximum Temperature Trend ˚C (1951-2000)

72

49. 50.

Fig. 5.7 d: (Apr-May) Mean Maximum Temperature Trend °C (1951-2000)

73

5.6.4 Summary of Zone-wise Mean Maximum Temperature Trends

Table 5.12: Zone-wise Summary of Mean Maximum Temperature Trend. (°C) (1951-2000)

Monsoon Winter Apr-May Oct-Nov Regions/Seasons Annual (Jun-Sep) (Dec-Mar) Zone 1(a): Greater Himalayas

0.63 -0.16 0.73 1.91 0.98 (Winter dominated) Zone I(b): I Sub-montane Region and 0.04 -0.46 0.08 0.55 0.29 I Monsoon dominated

ZoneII: -0.42 -1.10 -0.55 0.78 -0.25

Western Highlands ZoneIII:

-0.54 0.78 -0.06 Central & Southern Punjab -0.14 -0.20

Zone IV: -0.02 -0.17 -0.33 0.63 0.08

Lower Indus Plains Zone V(a): Balochistan Province 0.54 0.36 0.53 0.86 0.59 (Sulaiman & Klrthar Ranges) Zone V(b):

0.83 1.23 0.10 1.97 1.17 Balochistan Plateau (Western) Zone VI:

-0.08 -0.08 -0.20 -0.25 0.43 Coastal Belt

5.7 Discussion on Maximum Temperature Trends

Greater Himalayan region shows a warming trend on annual basis and in all season except during the monsoon (Jun-Sep) season.

•

Monsoon temperatures have dropped in zones I to JV except in the Balochistan Plateau.

•

Summer (Apr-May) temperatures have significantly increased in all the regions.

Balochistan Plateau has become warmer in all the seasons.

•

Coastal areas show a cooling trend on annual basis and in all seasons except for the postmonsoon period (Oct- ov).

Oct- Nov period has become warmer in all the zones except in zones II & III.

74

51. 52. 53. 54.

5.8 Trend graphs showing significant changes in Mean Minimum Temperature (1951-2000)

Some Sample Trend Graphs showing significant changes at 90, 95 & 99% arc shown in Figs 5.8 (a-h

5.8.1 Mean Minimum Temperature Trends (1951-2000)

Trend changes in mean minimum temperature on annual and seasonal basis shown for individual station in Tables 5.13 to 5. J 7 in Appendix IX

5.8.2 Mean minimum temperature trends for the period (1951-2000) are presented in contour form in Figs. 5.9(a-e). The purpose is to help interpolate the changes for other locations

Fig. 5.9 a: Annual Mean Minimum Temperature Trends (˚C)

77

78

55.

79

56. 5.8.3 Graphical Presentation of Zone-wise Mean Temperature Trends (1951-2000)

Mean minimum temperature trend changes are shown for different zones in Figs. 5.10 (a-e).

80

57. 58.

.lOtI

l2N

z,u

76N

Fig. 5.10 c: Winter Mean Minimum Temperature Trend 0 (1951-2000)

Fig. 5.10 d: (Apr-May) Mean Minimum Temperature Trend °C (1951-2000)

81

59.

Fig. 5.10 e: (OCt- Nov) Mean Minimum Temperature Trend ˚C (1951-2000)

82

5.8.4 Summary of Zone-wise Mean Minimum Temperature Trend (1951-2000)

Table 5.18: Zone-wise Summary of Mean Minimum Ternperatur Trends (˚C) (J 951-2000)

Regions/Seasons Annual Monsoon (Jun-Sep)

Winter (Dec-Mar) Apr-May Oct-

Nov

Zone l(a): Greater Himalayas (Winter dominated) -0.80 -1.58 -0.23 -0.10 -1.23

Zone l(b): Sub-montane Region and Monsoon dominated

-0.32 -0.68 -0.14 -0.19 -0.08

Zone II: Western Highlands - J A5 -1.82 -1.10 -0.60 -0.78

Zone III:Central & Southern Punjab

0.77 0.76 0.99

0.41 -0.35

Zone IV: Lower Indus Plains -0.20 -1.18 0.12 -0.02 0.00

Zone V(a): Balochistan Province (Sulairnan & Kirthar Ranges)

0.36 0.10 0.27 0.53 0.96

Zone V(b): Balochistan Plateau (Western) 1.33 lAO 0.67 2.20 2.50

Zone VI: Coastal Belt 0.l3 -0.23 0.25 0.43 0.23

5.8.5 Discussion on Minimum Temperature Trend

•

Mean minimum temperature have dropped in the Greater Himalayan region in all the seasons. When compared to the maximum temperature trend changes, these reflect enhanced diurnal temperature variations. Days have become wanner and night colder.

•

Balochi tan Plateau has become warmer in all the easons.

•

Summer (Apr-May) nights have become colder in the mountainous regions and in the Western Highlands.

•

Central and Southern Punjab has become warmer in all the seasons except during the monsoon season.

•

We tern highlands have beedme colder in all the seasons.

•

Coastal areas show warming trend except during the monsoon season.

83

5.9 Per-Year Percentage nnual Precipitation Trends (1951-2000)

Per year pcrccntaic precipitation trend change on annual and seasonal basis shown for individual tations in Tables 5.19 10 5.23 are placed in Appendix X:

5.9.1 Per-Year Percentage Precipitation Trends (1951-2000) on annual and seasonal basis arc presented in contour form in Figs. 5.11 (a-e). The purpose is to help interpolate the changes for other locations

Fig. 5.11 a: Per-Year Percentage Annual Precipitation Trends (mm)

84

60. 61.

Fig. 5.11 b: Per-Year Percentage Monsoon Precipitation Trend (mrn)

36

32

30

28

26

Fig. 5.11 c: Per- Year Percentage Winter Precipitation Trends (rnrn)

85

62.

Fig. 5.11 d: Per-Year Percentage Apr-May Precipitation Trends (mm)

Fig. 5.11 e: Per-Year Percentage Oct-Nov Precipitation Trends (mm)

86

63. 64.

5.9.2 Zone-wise Precipitation Trend over Pakistan (1951-2000) Per-Year percentage precipitation trend changes arc hown for different zones in Fig. 5.12 (a-e).

Fig. 5.12 a: Annual Percentage Precipitation Trend' in mm (1951-2000)

Fig. 5.12 b: Monsoon Percentage Precipitation Trends in mm (1951-2000)

65. 66.

,

88

67.

Fig. 5.12 d: (Apr-May) Percentage Precipitation Trends in mm (1951-2000)

Fig. 5.12 e: (Oct- ov) Percentage Precipitation Trends in mm (1951-20000

89

5.9.3 Summary of Zone-wise Percentage Precipitation Trends (19S1-2000) (yearly basis)

Table 5.24: Zone-wise Summary of Precipitation Trend Changes (mrn) (1951-2000)

5.10 Annual Precipitation Trend 1901-2000 for Pakistan with CRU Data

The CRU (Climatic Research Unit, UK) data developed by Dr. Tim Mitchell

(http://www.eru.tlca.ac.ukl-timm/index.html) for the whole globe on country basis was extracted for

Pakistan and a trend change was worked out (Fig. 5.13). Precipitation has increased by 25% over the

previous century. A general increasing trend in precipitation is also seen by the past data (1951-2000) in

Pakistan

90

Fig. 5.13: RU data: Annual Precipitation (mm) Trend 1901·2000 for Pakistan

5.11 Discussion on Precipitation Trends

5.11.1 Precipitation Trends (Monsoon)

Monsoon precipitation has increased in the Greater Himalayan region by around 2% a year whereas winter precipitation has slightly decreased.

Monsoon precipitation has increased in all the regions except in western parts of Balochistan in Region V (b). There is a significant drop in rains in the coastal region during the monsoon period.

Winter rains have significantly increased in the ub-rnontane areas in Region l(b). A mixed trend is seen in other regions.

Rainfall has mostly increased except in the hyper-arid areas of Balochistan around Nokkundi, Dalbandin & Panjgur and areas mostly along the coastal belt (except the eastern part of Sindh province) which has shown a decreasing trend.

5.11.2Precipitation Trends (winter)

Rainfall has slightly decreased in the Greater Himalayan region but significantly increased in the sub-montane regions, central & southern Punjab and in Balochistan Province Zone V(a).

• Rainfall has dropped in the Balochi tan Plateau, Zone V (b).

5.12 Monthly Extreme Trend Analysis

Extreme monthly maximum, minimum and precipitation trends are shown in the subsequent Table (5.25 to

5.27). Methodology is available in Para 5.2.

91

68. 69.

Table 5.25: Extreme Monthly Maximum Temperature Trends in different regions (1951-2000)

Table 5.26: Extrerne Monthly Minimum Temperature Trends in different region (1951 -2000)

92

70. Table 5.27: Extrerne Monthly Precipitation Trends in different regions (1951-2000)

5.13 Findings

5.13.1 Temperature Extremes More than 75% of the stations in the Greater Himalayan region show extreme monthly maximum

temperature increased. This reflects that tbe glacier and snow melt during the iummer months would likely enhance.

Desert have become further hotter. 80% of the stations in the Balochistan Plateau have become further hot. This would likely enhance the pressure gradient force between the Arabian Sea and the adjoining continental areas during the hot monsoon months providing more pulling force for the maritime air masses from the Arabian Sea during the monsoon .eason.

• Nights have become colder at more stations in the mountainous north in particular, the Sub-montane region. Similar is the situation in the Western Iighlands (Zone-If) which lies in the path of western disturbance.

5.13.2Precipitation Extremes • Extreme monthly precipitation events have increased at more stations in the Mountainous North. Seven out of 9 tatioru in the Greater Himalayan region and eight out eleven stations in the Sub-mointane region show such a trend.

Extreme wet events have also increased over all th stations in the Balochistan Province. Rainfall distribution has thus changed over the last fifty years (1951-2000).

There is an overall increase in the wet events over the country as a whole. Forty one stations out of fifty four stations how enhanced trend.

93

Chapter 6

Climate Variability and Change in the Mountainous North of Pakistan

6.1 Introduction

Mountainous North of Pakistan comprises parts of Karakoram, Hindukush and Himalayan

ranges. This region, particularly the Karakoram Range) abounds in sizable glaciers. The melting

of these glaciers and the snowmelt help keep the Indus River and its tributaries perennial

throughout the year. Any change in climate in this region will affect both the melting of glaciers

and snow over the mountains and consequently have aJ1 impact on the water availability in the

country. The temperature and precipitation changes may also lead LO a change in the ceo-system of

this region thereby affecting different socio-economic sectors not only in the region but also in

Pakistan as a whole.

The Mountainous North Located within the latitudes 33-37° and longitudes 71-76°E, covers the

northern parts of Pakistan and comprises parallel mountain ranges intervened by narrow and deep

river valleys. East of the Indus River, the mountain range in general run from east to west and to

its west - from north to south. The region comprises the following three significant ranges:

The Himalayas The Karakorams The Hindukush

The western most parts of the Himalaya fall in Pakistan. The sub-Himalayas - the southern most

ranges arc not very high and (ange within the heights 600 to 1200 masl. The Lesser Himalayas lie

to the north of the sub-Himalayas and rise to 1,800 to 4,600 masl. The Greater Himalayas are

located north of the Lesser Himalayas. They attain snowy heights of more than 4 GOO m.

The Karakoram Ranges in the extreme north rise to an average height of 6,100 m. Mount

Goodwin Austin (K-2) - the second highest peak in the world (8)610 m) is located in the

Karakorams.

94

The Hindukush Mountains take off the western side of the Pamir Plateau located to the west of the

Karakorams. These mountains take a southerly tU111 and rise to snowy heights. Some of the peaks rise

to great heights like Trich Mir (7,690 m).

6.2 Meteorological Stations in the Mountainous orth 15 meteorological stations are picked up for tudy (Table 6.1). The three ranges are shown in Fig 6.1

Table 6.1: Meteorological Stations picked up for tudy

S.l o. Range Station Height (m) Latitude (˚N) Longitude (˚E)

1 Bunji 1372 35.67 74.63

2 Gilgit 1460 35.92 74.33

Karakoram 3 Gupis 2156 36.17 73.40

4 Skardu 2210 35.30 75.68

5 Chitral 1500 35.85 71.83

6 Dir 1370 35.20 71.85 Hindnkush 7 Drosh 1465 35.57 71.78

s Saidu Sharif 962 34.73 72.35

9 Astor 2168 35.37 74.90

10 Balakot 981 34.38 73.35

11 hilas 1251 35.42 74.10

12 Himalayas uzaffarabad 702 34.37 73.48

13 Kakul 1 "09 34.18 73.25

14 Garhi Dupatta 13 34.22 73.62

15 urree 2168 33.92 73.38

71.

Fig. 6.1: Different Ranges in the Mountainous North of Pakistan

6.3 Data and Methodology used

Normal climate data for the thirty year period 1961-90 (values averaged over the 30 year period) and

the monthly climate data for the period 1951-2000 for the two variables Temperature (Mean

Maximum and Minimum) and total Precipitation are used and analyzed on annual and seasonal basis.

Thomthwaite's Aridity Index method has been used to climatically classify the region. Climate

variability in the region is based on the 30-year normal value' whereas the climate Changes have been

worked out using the data for the period (1951-2000). Regression analysis using the least square

method makes the basis of trend analysis. Changes are also worked out at 90-99% confidence levels to

see whether these changes are significant or otherwise. Seasons used in the study are: Monsoon (June-

September); Post Monsoon October-November); Winter (December-March) and Summer

(April-May) as is the normal practice in this report.

6.4 Climate Classification and Variability (1961-90)

The climate classification of Mountainous North is shown in Fig 6.2. The state of aridity and rainfall

variability in each range is shown in Table 6.2.

96

72.

Fig 6.2: lirnate Classification of the Mountainous North of Pakistan

Table 6.2: Clirnate Classification and Rainfall variability (1961-90)

Range Classification Total Rainfall (mm)

Annual Monsoon Winter Apr-May Oct-Nov

Range: Range: Range: Range: Range: Karakoram Hyper Arid 120-205 35-49 25-100 44-55 05-15

Average: 149 Average: 43 Average: 46 Average: 49 Average: 11 Semi Arid to Range: Range: Range: Range: Range:

Hindukush 440-1415 25-440 250-615 133-255 35-105 Humid Average: 875 Average: 233 Average: 388 Average: 184 Average: 70 'Range: Range: Range: Range: Range:

Himalayas Mostly Humid 175-1790 .>5-940 60-520 60-235 15-110 Average: 1231 Average: 594 A verage: 372 Average: 182 Average: 77

Karakoram Range is highly arid. The Karakoram and the Hindukush range' are basically

winter-rain dominated ranges 'where as the Himalayan range is winter dominated for station

above 35°N and monsoon dominated below 35° N . The period Oct- Nov is the driest in all the

three ranges.

97

6.5 Spatial Temperature Variability:

The spatial patterns with regard to temperature (mean maximum and minimum) are shown in Tables

6.3 a-c for different seasons and for different ranges:

Table 6.3a: Mean Temperature Variability (1961-90)

Table 6.3b: Mean Maximum T mperature Variability (1961-90)

Table 6.3c: Mean Minimum Temperature Variability (1961-90)

98

6.6 Past Temperature Trend Changes in the Region

Using the past Climate data of Pakistan (1951- 2000), the trends in mean, maximum and minimum

temperatures have been computed for different seasons and the three mountain ranges. Changes

significant at 90, 95 or 99 % confidence level are also worked out (Tables 6.4 to 6.6),

Table 6.4: Mean Temperature Trends during Monsoon (Jun-Sep)

Table 6.5: Mean Temperature Trends during winter (Dec-Mar)

99

Table 6.6: Mean Temperature Trends during summer (Apr-May)

6.6.1 Summary of Mean Temperature Trends Monsoon season has become colder in all the three ranges reflecting decreased snow and

glacier melt during the season. Drop in temperature ill the Karakoram range is more

pronounced and statistically significant.

Winter on the average bas become warmer in the Karakoram and Hindukush ranges.

Statistically significant increase is seen at Skardu and Chitral. More stations, in the Himalayan

range also show warming trend, though slight. Only the station Kakul shows a significantly low

temperature. Precipitation as a result, may rail more as rainfall than snow in all the three ranges thus enhancing the probability of somewhat higher base flows in the Indus Basin Rivers

during winter.

• Summer(Apr-May) has significantly become warmer in all the three ranges thus reflecting enhanced

snow and glacier melt contributions. Consequently the base flows in the rivers in the

pre-monsoon period may enhance the probability of disastrous floods when superimposed by

heavy monsoon rains in the subsequent monsoon months.

6.7 Mean Maximum Temperature Trends in the Region These for different sea: ons are shown in Tables 6.7 to 6.9.

100

Table 6.7: Mean Maximum Temperature Trends during Monsoon (Jun-Scp)

Table 6.8: Mean Maximum Temperature Trends during Winter (Dec-Mar)

101

Table 6.9: Mean Maximum Temperature Trend during Summer (Apr-May)

6.7.1 Summary of Mean Maximum Temperature Trends

Mean maximum temperatures during the monsoon season show a decreasing trend ill the

Karakoram Range as well as in the Himalayas whereas an increasing trend is seen in the 1

indukush Range. The highest negative trend i. seen at Bunji with a confidence level of

99%.Skardu shows the highest warming trend at the same confidence level of 99%.

All the ranges show a warming trend during winter. 80% of the stations show an increasing

trend with 5 stations significant at 90 to 99% confidence level. Probability of winter

precipitation to fall as rainfall compared to snowfall is likely to enhance.

Maximum temperatures have significantly gone up in all the three ranges during the

summer (Apr-May) months. This is the period when snow and glacier melt practically

starts. The warming trend indicates enhanced snow and glacier melt and consequently can

contribute towards raising the likelihood of enhanced base flow in the Indus Basin rivers in

the ubscqucnt summer monsoon months and thus raising the probability of severe floods

when super-imposed by severe monsoon rains.

102

6.8 Mean Minimum Temperature Trends in the Region These for different seasons are hown in Tables 6.10 to 6.12

Table 6.10: Mean Minimum Temperature Trends during Monsoon (Jun-Sep)

Table 6.11: Mcan Minimum Temperature Trends during Winter (Dec-Mar)

103

Table 6.12: Mean Minimum Temperature Trends During Summer (Apr-May)

6.8.1 Summary of ean Minimum Temperature Trends

All the three ranges show a decreasing trend in the mean minimum temperature during

the monsoon season. Nights thus have become colder in all the three ranges. Decreasing

trend is more significant in the Karakoram Range.

Minimum temperatures have dropped in all the ranges during the winter season Nights

have thus become colder whereas days have become warmer when seen in the context of

maximum temperatures during winter.

During the summer season, negative trend is seen in the Karakoram and Hindukush

Ranges with higher temperature trend in Himalayas. Summer nights have thus become

colder in the Karakoram and Hindukush Ranges.

6.9 Past Precipitation Trends in the region

Percentage precipitation trends on yearly basis arc worked out for both the monsoon & winter

seasons. Changes significant at 90 95 or 99 % level arc also worked out (Tables 6.13 and 6.14).

104

Table 6.13; Per Year % Monsoon Precipitation Trends (1951-2000)

Table 6.14: Per Year % Winter Precipitation Trends (1951-2000)

lO5

6.9.1 Summary of Precipitation Trends

All the three ranges show an increa ing trend during the monsoon season. 75% of the stations in the

Karakoram Range show statistically significant increase. Increasing trend is seen in the Hindukush

and Himalayan Ranges during winter whereas a decreasing trend is seen in the Karakoram Range.

Murree in the Himalayan Range shows the highest increase in winter.

106

Chapter 7 Analysis of Driest Periods and Drought Vulnerable

Areas in Pakistan

7.1 Introduction

Driest precipitation periods for fifty one stations available in the thirty year climatic normals of

Pakistan (1961-1990) make the basis of thi analysis. Number of years each station remained dry that is,

it received zero precipitation during a month, is used to find the percentage of the time it remained dry

during different seasons. Thi information is then used to identify the drought vulnerable area. Drought

is a normal, recurrent manifestation of climate with its features varying from region to region. A

precise definition of drought is therefore difficult. Based however, on many definitions that appear in

the literature, it can be defines as:

1) Drought is the prolonged absence of precipitation in a pecific area.

2) There is seasonal drought at a place when it get rain half a year.

3) In Britain, drought can be a little as 15 rainless days.

In order to mark areas a drought vulnerable maps showing the regions remaining dry for more than

50% of the time during different seasons arc prepared. In the coun ry, there are two main rainy seasons

namely winter (December-March) and summer men oon (JuneSeptember) and two tran ition periods:

Pre-monsoon (April-May) and po t monsoon (October- ovember) periods when there are almost

insignificant rain in the country. In each season, there is at least one region in the country, which on the

average remains dry for more than 50% of the time and thus makes it vulnerable to drought and then

drought prone depending upon the rains in the subsequent seasons i.e. when there is prolonged

absence of precipitation in that region. Such a situation can be predicted well before time if the

monitoring and early warning system is reliable. It is here clarified that a plac remaining dry for more

than 50% of the time means that out of 30 years, the normal period of the data the place receives zero

rainfall in more than 15 years for a particular month i.e. for more than 50% of the total period.

The major parts of the southern plains of Pakistan are ba ically arid to hyper-arid as reflected by the

spatial annual precipitation (Chapter 4), the su ceptibility of different regions in this part to become

drought vulnerable in different easons is very high. To sec as to what i the rainfall situation in each

drought vulnerable region, we first see as to what is

73. the estimated rainfall di tribution over the different provinces of Pakistan worked out using the

Theissen Polygon method using the 30-year normal values (Table 7.1). The provinces of Sindh,

Balochistan and part of Southern Punjab are located in southern parts of Pakistan.

Table 7.J.: eason-wise 'Weighted Precipitation (mm) over the different Provinces of Pakistan

PERIOD NWFP PUNJAB BALOCHISTAN SIND Dec to March 228.8 81.1 69.3 14.2 June to September 252.9 260.3 64.2 137.5 April to May 106.5 36.5 20.1 5.5 October to November 37.7 11.3 4.8 4.4

Source: Pakistan Meteorological Department of Pakistan

7.2 Data and Methodology Used

Driest period are drawn from the 30-year normal period (1961-1990) and their percentages are worked

out for all rations and for different season. Table 7.2 shows some 51 places where eason-wise

percentage of the time ·tations remained dry arc given. Contour maps are then raised for all seasons

using thi data. Areas remaining dry for more than 50% of the time are then separated out as drought

vulnerable areas. The vulnerable areas in different Seasons are then discussed in the context of rainfall

activity during the subsequent season and discussed as to how a vulnerable region finally become

drought prone. The map of Pakistan with its different provinces i.e. shown in Fig. 7.1.

Fig. 7.1: Map Showing the Provinces of'Pakistan

108

7.3 Vulnerable and Drought Prone Areas Drought vulnerable areas are di cussed in the context of rainfall received during the subsequent seasons

over different region of the country and then reasons leading to different areas becoming drought prone

Are disscussed

7.3.1 Winter Rains (December-March) Western disturbances Or the low pressure, ystcms having their origin in the Mediterranean Sea or

Atlantic Ocean travel eastward aero s Iran Pakistan and India and affect the regions generally north of

300N and give rise to cloudiness and precipitation. The mountainous north, because of its topography

helps extracting the moisture from these western disturbances. At times these disturbances induce

secondaries in the lower latitudes below 30° N and get further accentuated by Moisture feeding from

the Arabian Sea and cause widespread rains in the country. But these western disturbances still rarely

reach the Sindh province, the region down in the south-eastern part of Pakistan. These areas thus get

insignificant rains during the sea on and u ually remain dry for more than 50% of the time. When there

are no winter rains in the e areas, they are vulnerable to drought (Fig. 7.2). Weighted precipitation

(Table 7.1) also confirms receipt of very low rains in the Sindh Province.

Fig 7.2: Drought Vulnerable areas during winter (1961-1990)

109

74.

7.3.2 Summer/Pre-Mon oon weighted precipitation (April- May) The province of Sindh compared to other provinces again get lowest weighted precipitation

during the period. ext i the province of Balochistan where rainfall on the average i higher

compared to the Sindh Province but there arc still some area in the province where some remain

dry by mor than 50% of the time (Fig. 7.3). Most parts of the Sindh Province and western parts of

Balochistan remain dry for more than 50% of the time and arc thus vulnerable to drought.

Fig: 7.3: Drought Vulnerable areas during Apr-May (1961-1990) In case winter rains fail in the indh Province and the subsequent months of April and May also

bring no or insignificant rain things with regard to it vulnerability to drought would further

aggravate and it may now tum out to be a drought prone region. Simultaneously parts of

Baluchistan arc now vulnerable to drought as the e areas also remain dry for more than 50% ofth

time during this season.

7.3.3 Monsoon Rains (June- eptember) The rains during the period (June-September) are brought by the monsoon y terns depressions

emerging either from the Arabian Sea as outh westerly currents or from the Bay of B ngal a south

easterlies. The e monsoonal currents rarely affect the western part of Balochistan. The weighted

precipitation during the as on is hown for different provinces in Table 7.1 Weighted precipitation

in Balochistan is the least compared to other provinces. The areas having driest periods for more

than 50% of the times arc

110

shown in Fig. 7.4. The province of Smdh 1s now likely overcome the drought situation which it

could have developed during the previous two seasons winter and summer) but it still has the

probability of remaining dry for more than 25% of the time. Tn ca e it come, to such a situation again

where it receives very little rainfall during even the monsoon season, it is sure to become a drought

prone region which would now be facing the prolonged ab 'enee of precipitation. This is however rare

in indh Province. During this season the station remaining dry for more than 50% of the time in

Balochistan seem to have increased compared to the previous period of April-May. In case of failure

of rainfall during this season, most parts of Balochistan are likely to become drought prone.

Fig. 7.4: Drought Vulnerable area during the Monsoon Season (1961-1990)

7.3.4 Post-Monsoon Season Rains (October-November) The rainfall during this season drastically drop compared to all the other three seasons (Table 7.1).

Fig. 7.5, with two minor exceptions, one around Barkhan and the other around Lasbella, show the whol

of Southern Pakistan below around 32°N, as getting dry for more than 50% of the time. These

constitute major parts of southern Punjab and the province' of Sindh and Balochistan, This period of

the year thus makes half of Paki tan as drought vulnerable and its likelihood to become drought prone

is very high if the rains in the monsoon season has already failed and winter rains also bring

insignificant rains.

III

75.

70

72

76

Fig. 7.5: Drought Vulnerable area during Oct- Nov (1961-1990)

7.3.5 Conclusion:

This is the one approach adopted for the study of drought vulnerability in Pakistan. It needs to be

studied from other angles and approaches too to make it more perfect and reliable a thi creeping

disaster is also affect the ecosystem and multitude of socioeconomic sectors.

112

113

Chapter 9

ENSO and NAO Influences over the Weather of Pakistan

8.1 Introduction

The El-Nino Southern Oscillation (EN SO) phenomenon is associated with anomalous sea-level pres ure,

surface winds and SST ncar the equatorial Pacific (Barton ct al 2004) and is caused by the sea level

pressure gradient between Darwin (Australia) and Tahiti (Wallace and Vogel, 1994). It has now been

recognized that the single most important key to earth's year-to-year climate variability is the El- Nino

Southern 0scillaiion phenomenon (Kriplani R.H. 1996). El-Nino episodes directly affect the climate of

at least half the planet and in many instances result in heavy lo s of life and resource. (ibid). Th Southern

Oscillation Index (Sal) used in the study is the air pre sure anomaly between Tahiti and Darwin

(Australia). The negative phase of the SOl represents the below normal pre ure at Tahiti and above

normal pressure at Darwin and vice versa for the po itive pha e of the SOL Prolonged periods of negative

OJ values coincide with abnormally warm ocean waters across the eastern tropical pacific (El-Nino

episodes) while the prolonged periods of positive SOl values coincide with the abnormally cold ocean

water across the tropical Pacific (La-Nina episode) (philander, 1990)

The NAO describes a large-scale meridional oscillation in the atmospheric mass between the

North Atlantic regions of the subtropical anticyclone near the Azorc and the lib polar low pressure system

near Iceland. It is a major source of seasonal to inter decadal variability in the worldwide atmospheric

circulation (Hurrell, 1995) and represents the most important "tclcconncction" of the North

Atlantic-European area (Hurrell and van Loon, 1997; Kapala ct al. 1998), where it is most pronounced in

winter. The measure of the state of NAO the North Atlantic Oscillation Index (NAOI) is widely used as a

general indicator for the strength of the we ierlics over the eastern orth Atlantic and Western Europe and

most importantly for winter climate in Europe (Hurrell and van Loon, 1997" Wanner ct al., 1997; WMO

1998). In fact, the 1 AOI is highly correlated with a large variety of atmo phere-related environmental

variables mainly during the 'winter season (Dickson et at, 2000 and Souriau and Yiou, 2001)

In this study, ENSO and NAO phenomena and their indices have been studied in relation to rainfall

departures (monsoon rains in case of ENSO and winter rains in the case of NAOI). The

114

rainfall departures arc worked out for June to September (HAS) for monsoon dominated region (Fig. 1.3)

referred to as "Monsoon Region '.

8.2 Data and Methodology Used

Greater Himalayan region within 35°N to 37° is mostly winter rain dominated whereas the region within

31.5° to 35°N located along the southern slopes of western Himalayan mountains is monsoon rain

dominated. Monsoon (June to eptember) and winter (December to March) precipitation data for a fifty

year period (1951-2000) for 20 meteorological stations, 9 located in the greater Himalayan (winter

dominated) region and 11 in the monsoon dominated sub-montane and adjoining region, are used. SOT

values differing from its mean value by more than -1σ and +1σ to have re rpectively been termed as

El-Nino and La Nina events. There i. however, no single method used to identify the El-Nino and La- ina

events. A common method in LIS is bas ed On the Nino 3.4 Index, which is the departure in monthly sea

surface temperature from its long term mean averaged over the Nino 3.4 region.In this method, an event is

identified as 1::.1 Nino if the 5 month running average of the ino 3.4 Index exceed +OAoC for at least G

consecutive months and is La Nina if the same falls below -O.4°C for at least 6 con ccutivc months. III (his

study, El Nino and La-N ina events which are common to those based on the Tahiti minus Darwin

pressure on ino 3.4 index and on the Sal values above and below) standard deviation have been

considered. The SOl values have been related to the rainfall departures from the mean of monsoon rain

over the Monsoon Region for the period 1951-2000 and to the mean precipitation of the mountainous

regions above and below 35°N Correlation coefficients are then worked out. During the El Nino years, the

pressure conditions over the South Asia region using the CEP reanalysis data have also been examined to

see as to what could be the position of pressure patterns over the region during the ENSO periods. ENSO

composites of precipitation are also developed using the CRU TS 2.0 precipitation gridded data collected

from the Climate Research Unit (CRU), SA.

Analysis is also carried out for identifying the correlation of - AOI values differing from its mean value by

more than one standard deviation, with the precipitation in the regions above and below 35°N. Dccadal

correlations between rainfall departures and NAOI in extreme NAOI years are also developed for the

regions 35° - 37°N & 31.5°N-35°N.

115

8.3 ENSO (El-Nino & La-Nina) Tele-connections

Rainfall departures of Monsoon Region of Pakistan from the corresponding long term

mean (1951-2000) during the EI Nino and La Nina years are shown in Table 8.1 (a) &

(b).

Table 8.1: Rainfall Departures from 1951-2000 mean values for EI Nino and La Nina

years

In the Monsoon Region, five out of seven EI ino events that occurred in the period

1951-2000 are found associated with deficient rainfall. Rainfall departure was positive

during the years 1994 and 1997. In case of La Nina years, four events showed excess

rainfall whereas only one (that in 1998) showed deficit rainfall.

Fig. 8.1 shows the correlations of SOl (JJAS) on annual basis with rainfall departures of

Monsoon Region for the period 1951-2000. During the monsoon period (JJAS) the

positive correlation over Monsoon Region is significant at 95% level which indicates

that more rainfall occurs in La ina years compared to the E1 ino years.

116

76.

Fig. 8.1: Variation of SOl with Rainfall Departures from the 1951-2000 mean value during June-se

Fig. 8.2 hows the annual patterns of SOl (JJAS ) with rainfall departures of Monsoon Region in case of El-

mo years.

Fig. 8.2: Variation of SOl with Rainfall Departures from the 1951-2000 mean value for Jun-Sep during EJ ino years

Fig.3 shows the annual pattern of SOl (JJAS) with rainfall departures of Monsoon Region in La- Nina

years.

117

118

Fig. 8.3: Variation of SOl with Rainfall Departures from the 1951-2000 mean value for Jun-Sep during a Nina years

8.4 Correlation of SOl Values with Decadal Rainfall Departures

Decadal correlation coefficients of OT with rainfall departures in Monsoon Region are shown in Table

8.2. In the Monsoon Region positivc correlations are seen during the decades 1951- 1960, 1961-1970,

1981-1990 and a negative correlation during 1991-2000.

Table 8.2: Variation of SOl with rainfall departures from the 1951-2000 mean values for di fferent decades (June - Sep)

Decadal Correlation Cocfficient

Decade Monsoon Region 1951-1960 0.49 1961-1970 0.79 1971-1980 0.13 1981-1990 0.79 1991-2000 -0.43

Some significant correlation during the decades 1961-1970 & 1981-1990 and a negative correlation

during 1991-2000 are shown in Fig. 8.4 (a), (b) & (c)

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8.5 Monsoon Depressions reaching Pakistan during the El-Nino Years

The available records of monsoon depression (Annual Flood Reports, Paki tan Meteorological

Department) for the period 1971-2000 approaching Pakistan from the Bay of Bengal and the Arabian

ea during the El-Nino years, show that no monsoon depression could reach Pakistan except in 1997. J n

J 997, only two depres ions could manage to enter Pakistan. No monsoonal system of the level of a

depression could develop in the Arabian Sea in any of the E1 Iino years (Table 8.3).

Table 8.3: Monsoon Depression reaching Pakistan from Bay ofBcngal and Arabian Sea during the El

Nino years

Year Depressions from Bay Depressions from Depressions reaching

of Bengal Arabian Sea Pakistan 1972 5 - Nil 1982 7 - Nil 1987 1 - Nil 1993 1 - it 199 Record not available - - 1997 6 - 2

Source: Pakistan Meteorological Department

8.6 ENSO Composite of geo-potential Heights over South Asia Region and precipitation patterns during EI Nino and La Nina Years

During the El- ino years, most of the depression dissipated over Bangladesh or over India. The

geo-potential height pattern during the El-Nino years compared to La-Nina years developed using the

NCEP pressure (850 hPa) reanalysis data (Fig 8.5) hewed that the situation was not conducive for the

uninterrupted flow of depressions from the Bay of Bengal because of increased geo-potential heights at

850 hPa over India compared to the Bay of Bengal.

-.

120

77.

Fig. 8.5: ENSO composite of gee-potential heights at 850hpa over South Asia

Using the CRU T 2.0 precipitation data set validated for Paki tan, a composite picture was developed

over South Asia for the El- Nino and La- Nina years (Fig. 8.6). Rainfall if; seen drastically dropped

over upper parts of Pakistan.

121

78.

Fig. 8.6: ENSO composite of precipitation mm/d) over South Asia

CRU based precipitation patterns during the monsoon season and winter season in Pakistan are

respectively shown in Figs. g.7 (a) & (b) for comparison. Both mon oon and , v inter rain are concentrated

in the sub-montane regions between around 32° to 35°N.

122

Fig. 8.7: CRU Precipitation in mm/d during JJAS and DJFM over Pakistan

8.7 Rainfall Extremes versus ENSO Episodes

Rainfall events in the Mon oon Region that remained above 1 Standard Deviation (0) from the 1951-2000

mean value during different years are examined in the context of ENSO episodes mentioned against each.

(Table 8.4)

Table 8.4: Rainfall Extremes above 1σ versu: ENSO Episodes

(C-), weak La-Nina; (W-), weak EI-Nino; (W), moderate EI- Nino; (W+), strong El-Nino; (N), neutral:

Source: NOAAfNational Weather Service, USA

123

Extreme rainfall events occurred during either the weak El- ina or La-Nina years or during the

neutral years except during 1994 & 1997 which had have respectively the moderate and strong EI-Ninos.

In 010 t of the cases heavy rain in the upper catchments of the rivers caused flooding downstream. The

years 1955, 1959, 1973, 1976, 1992 & 1997 witnessed catastrophic flood in Pakistan. (Annual Flood

Reports, PMD)

The position in case of precipitation event below 1σ remained as in Table 8.5.

Table 8.5: Rainfall zxtrernes below 1 σ versus" ENSO Episodes

Years Below Classification

1952 1 σ N 1957 1 σ w 1965 1σ W 1969 1 σ \v- 1982 1σ WtoW+ 1987 1 σ W+

Most of the cases have deficient rain during both the moderate and. trong EI Nino years.

8.8 North Atlantic Oscillation (NAO) Forcing Extreme AOI values falling above and below 1 standard deviation were identified. Value of

NAOI (Dec - Mar) were correlated with the rainfall departures from the 1951-2000 mean values for winter

(Dec - Mar) in the mountainous regions below and above 35° within the region 31.5° to 37° . Table 8.6

hows the correlation coefficients for the three regions: the regions above 35°N and below 35°N.

Correlations are positive with winter (DJFM) rainfall departures in both the regions.

Table 8.6: Variation of AOI with rainfall departures

Whole Data NAOI fDJFM)

Rainfall Departure (Region 0.29 31.5°N - 35°N)

Rainfall Departure (Region 0.18

35°N - 37°N)

Correlations related to Table 8.6 are hown graphically for NAOI in Figs. 8.8 (a) & (b)

124

79.

Fig. 8.8: Variation of rainfall departure with NAOI in different regions

Extreme NAOI values falling above and below 1 standard deviation were identified and correlated with rainfall departures from 1951-2000 mean values for winter (Dec- Mar) for the tv 0 mountainous regions. Positive correlation were found with NAOr values (Table 8.7)

Table 8.7: Correlation of Extremes AOI values with the rainfall departures from the 1951-2000

mean values

125

I

Fig. 8.9: Variation of rainfall departure with extreme NAOI years

Decadal correlations of A I with winter rainfall departures from the 1951-2000 mean values for the

period (Dec-Mar) for the two regions are at 0 computed and are shown in Table 8.8 for the region

above 35° and below 35°N.

Table 8.8: Decadal correlation of NAOI values with rainfall departures from the 1951-2000 mean values for different region

Decadal orrelation Coefficient

Decade Rcgion Region 31.5°N - 35°N 35°N - 37°N

1951-1960 0.49 0.10 1961-1970 0.33 -0.17 1971-1980 0.45 0.63 1981-1990 0.31 0.05 1991-2000 -0.19 -0.25

126

80. 81.

Decadal correlation of NAOI values with rainfall departures In the two regions in the mountainous

north are shown for the decades 1971-1980 and for the decade 1991-2000 in Figs8.l0 (a), b), (c) &(d)

127

82.

Fig. 8.10: Decadal correlation between AOI and Rainfall departure in different regions during 1971 - 1980 and 1990 - 2000 decades.

8.9 Conclusions:

1. EI-Nino years are associated with deficient rainfall over Monsoon Region. The pattern,

however, changed in the last decade (1991-2000) and had excess rains.

2. La- Nina years are generally positively correlated with rainfall departures except during the

last decade of 1990

3. AOI values were seen to have a positive correlation with winter rains for the region 31.5-35°

N. Correlations with the winter dominated region above 35°N , however remained

comparatively low.

4. The composite pattern of Goo-potential heights over India, the passage for the flow of

monsoon depressions from Bay of Bengal to Pakistan, indicated higher pressure over most of

India compared to the pre sure over Bay of Bengal blocking the uninterrupted flow' of

monsoonal systems to Pakistan.

5. The ENSO composite of precipitation pattern over South Asia showed drastic drop in rainfall

over the upper parts of Pakistan.

128

References:

129

130

APPENDICES

131

Appendix I

Table 2.1: Inventory of Meteorological Station:

132

Appendix II

Table-2.2: List of Stations during 1931-60 and 1961-90

133

Appendix III

Fig. 3.3: Monthly Temperature Variations at Bahawalnagar

Fig. 3.4: Monthly Temperature Variations at Bahawalpur

Fig. 3.5: Monthly Temperature Variation at Balakot

134

135

136

137

138

139

140

141

142

144

145

146

147

148

149

Appendix IV

1 able 3.14: Annual & Seasonal Mean Temperature (˚C) Distribution (1951-2000)

150

Table 3.15: Annual & Seasonal Maximum Temperature Distribution in °C (1951-2000)

151

Table 3.16: Annual & Scasonal Minimum Temperature (°C) Distribution (1951-2000)

152

83. 84.

Appendix V

Fig. 4.3: Monthly Precipitation pattern at Bahawalnagar

Fig. 4.4: Monthly Precipitation pattern at Bahawalpur

Fig. 4.5 Monthly Precipitation pattern at Balakot

153

85. 86. 87.

Fig. 4.6: Monthly Precipitation pattern at Barkhan

Fig. 4.10: Monthly Precipitation pattern at Chhor

Fig. 4.10: Monthly Precipitation pattern at Chilas

Fig. 4.11: Monthly Precipitation pattern at Chitral

155

88. 89. 90.

156

91.

157

158

Fig. 4.21: Monthly Precipitation pattern at lslamabad

Fig. 4.22: Monthly Precipitation pattern at Jacobabad

Fig. 4.23: Monthly Precipitation pattern at Jhelurn

159

92.= 93.

160

Fig. 4.24: Monthly Precipitation pattern at Jiwani

94. 95. 96.

161

97.

Fig. 4.31: Monthly Precipitation pattern at Lahore

Fig. 4.32: Monthly Precipitation pattern at Multan

162

Fig. 4.30: Monthly Precipitation pattern at Kotli

98. 99.

163

100.

164

101. 102. 103. 104.

165

105. 106.

166

168

Appendix VI

Table 4.5: Station-wise Annual and Seasonal Precipitation Pattern (1951-2000)

169

Appendix VII Mean Temperature Trends (195'(-2000)

Trend' in mean temperature on annual and sea ronal basi' are shown for individual rations in abies 5.1 to 5.5.

Table 5.1

170

Table 5.2: Mean Temperature Tr nd (1951-2000)

171

Table 5.3; Mean Temperature Trend. (1951- 2000)

.-

172

Table 5.4: Mean Temperature Trend (1951-2000)

173

Table 5.5: Mean Temperature Trends (1951·2000)

l74

Appendix VIII Mean Maximum Temperature Trend (1951-2000)

Trend changes in mean Maximum Temmpcraturc on annual and 'en ronal basis are, hown for individual station Table 5.7 to 5.11

Table 5.7

175

Table 5.8: Mean Maximum Temperature Trend' (1951-2000)

r

-'

176

Table 5.9: Mean Maximum Temperature Trend Changes (195l-2000)

177

Table 5.10: Mean Maximum Temperature Trend Change (1951-2000)

178

Table 5.11: Mean Maximum emperaturc Trend bung (1951 -2000)

179

Appendix IX Mean Minimum Temperature Trend Changes (1951-2000)

Trend changes in mean minimum t rnperature on annual and sea sonal basi shown for individual stationin Table 5. l3 to 5.17

Table 5.13

"

180

Table 5.14 Mean Minimum Temperature Trend change (1951-2000)

181

Table 5.15: Mean inimurn Temperature Trend change (1951-2000)

182

Table 5.16: Mean Minimum Temperature Trend change (1951-2000)

183

Table 5.17: Mean Minimum Temperature Trend change. (195 1-2000)

184

Appendix X

Table 5.19: Per Year % age Anoual Precipitation Trend (1951-2000)

185

Table 5.20: Per Year % age Monsoon Precipitation Trend (1951-2000)

<,

186

187

Table 5.22: Per Year %age (Apr-May) Precipitation Trend (1951-2000)

188

Table 5.23: Per Year % age (Oct- Nov) Precipitation Trend (1951-2000)

189