47

CHAPTER 3

STUDY AREA AND DATA COLLECTION

3.1 GENERAL

In a growing number of countries and regions of the world, water

has become the single most important constraint to food production. Both

sustainable food and livelihood security will depend on how well the water

resources is managed. India experiences extremes of climate within the 329 M

ha of geographical area. The rainfall is monsoonic and unevenly distributed

both spatially and temporally. Mean annual rainfall varies from 100 mm in

western Rajasthan to over 11000 mm at Cherrapunji in Meghalaya (Indian

Water Resources Society 1994). The incidence of rainfall is also seasonal,

occurring mainly during the Southwest Monsoon (June to September) in most

parts of the country except Tamil Nadu State.

The average annual flow in the river systems of India is assessed to

be 1869 TM m3

. The major constraint in utilizing all the available water is the

fact that it is necessary to store the river flows during monsoon months.

Nearly 60 % of India’s river flow is carried by the Rivers Ganga,

Brahmaputra and Barak, which command only 33 % of the geographical area

of the country.

India has sizable resources of water and large area of cultivable

lands but also a huge population to feed. With the present population of

around 100 crores, the per capita water availability comes to about 1170

m3/person/year (NIH, 2010). Though India’s per capita availability is greater

48

than “Water Stress Index”, (If water availability is below 1000 m3/capita/year,

countries experience chronic scarcity, Falkenmark 1989) there are regions and

States which fall into the category of water scarce territory. Tamil Nadu is one

of the water scarce States of India.

3.2 TAMIL NADU STATE

Tamil Nadu State lies between Latitudes 8° 5’ N and 13° 55’ N and

between Longitudes 76° 15’ E and 80° 20’ E. The State has a long eastern

coast stretching for nearly 1000 km. The geographical area of the State is

1,30,160 km2, which is 4% of the geographical area of the country and holds

7% of the population of the country. Tamil Nadu has a tropical climate. The

normal maximum and minimum temperatures (expect in the hill areas) are

450C and 18

0C respectively. The State has four distinct seasons:

(i) Southwest monsoon June to September

(ii) Northeast monsoon October to December

(iii) Winter season January to February

(iv) Summer season March to May

The Western part of the State, especially the portions closer to

Western Ghats benefit from the Southwest monsoon. But the Eastern coastal

belt gets most of the rain during the Northeast monsoon. The intermediate

plateau has poor rainfall and there are pockets that are chronically drought

prone. The average rainfall is 925 mm. The distribution and variability of

rainfall in Tamil Nadu are quite significant. Rain is not evenly spread

throughout the year, but is concentrated, on an average of 23 rainy days each

during Southwest and Northeast monsoons. Variations in rainfall are

significant within the Northeast monsoon being considerably more erratic

than the Southwest monsoon.

49

The State Agricultural Department has divided Tamil Nadu into

seven agro-climatic zones based on rainfall distribution, irrigation potential,

cropping pattern, soil characteristics and other physical and ecological

features. The zones and the districts falling under each zone along with the

mean annual rainfall are given in Table 3.1.

Table 3.1 Rainfall details of Agro Climatic Zones of Tamil Nadu State

Sl. No.Agro Climatic

ZoneDistricts

Average Rainfall

(mm)

1.North-eastern

zone

Kancheepuram

1099.1

Tiruvallur

Vellore

Tiruvannamalai

Villupuram

2.North-western

zone

Dharmapuri

846.67Salem

Namakkal

3. Western zone

Erode

653.65Coimbatore

Karur

4.Cauvery Delta

zone

Thanjavur

1028.08

Nagapattinam

Tiruvarur

Tiruchirapalli

Cuddalore

Pudukkotai

5 Southern zone

Ramanathapuram

822.28

Virudhunagar

Sivagangai

Thoothukudi

Dindigul

Madurai

Tirunelveli

6High rainfall

zoneKanniyakumai 1456.8

7 Hilly zone

Nilgiris district and Shevaroys,

Elagiri, Javadi, Kollimalai,

Pachamalai, Anamalais, Palanis and

Podhigaimalai hill ranges.

1857.0

50

3.3 STUDY AREA

Palar Sub basin, encompassing Vellore (a chronic drought prone

district), located in the North-East part of Tamil Nadu State is selected as the

study area. As the droughts are dealt in terms of administrative units (State,

District and Block) by the Central and State Governments for assessment and

mitigation purposes, the district is taken as a base unit for this study.

However, analyses were carried out on watershed basis wherever necessary

and the results are given in terms of administrative units such as blocks within

the district.

The index map of the study area is given in Figure 3.1. Vellore

district, is one among the 16 districts covered under Drought Prone Area

Programme (DPAP) in Tamil Nadu Sate as on November 2008. The total

geographical area of the district is 5920 km2. Major portion of the district falls

under the influence of agro-climatic Zone I (North-eastern zone) and partly

under Zone II (North-western zone). The district lies between 12015’23” N

and 13012’32” N Latitudes and 78

024’16” E and 79

054’56” E Longitudes.

Vellore district is conspicuous by the absence of perennial rivers and frequent

susceptibility to recurring droughts. Geologically the entire district is

underlain by hard rock formations, excepting few isolated patches of

sedimentary formation. Physiographically, the district can be broadly

classified as hilly terrains and plain regions.

3.3.1 Details of Major and Minor river basins

The study area is covered by two major river basins namely Palar

river basin and Ponnaiyar river basin. Palar is one of the major river basins in

Tamil Nadu State.

51

Figure 3.1 Index map of the study area

52

The main river Palar originates in Nandhi Durg of Kolar district at

an elevation of 800 m above MSL in the Eastern part of Karnataka State,

passes through the hilly portion of South Western part of Andhra Pradesh

State, enters Tamil Nadu State west of Vaniyambadi town and falls into the

Bay of Bengal between East of Madurantakam town and South of

Mahabalipuram town. Total area of the Palar basin (including an area of 3123

km2

in Karnataka State and 4267 km2 in Andhra Pradesh) is 18300 km

2.

Vellore, Tiruvannamalai and Kanchipuram are the districts covered by Palar

basin in Tamil Nadu State.

The river Palar flows through a length of 295 km in this district

from its entry near Pullur village in Tiruppathur taluk. Palar is not a perennial

river and occurrence of flood is very rare and of very short duration. During

the major part of the year, the river is dry and the flow is limited to a shorter

period. Springs all along the sandy bed are the main source of supply during

non-monsoon months.

Poiney and Cheyyar rivers are the tributaries of Palar. Poiney

originates from the hills of Seshachalam in Chandragiri taluk of Chittoor

district in Andhra Pradesh. It confluences with Palar near Karai village of

Walajahpet taluk. Cheyyar is the major tributary of Palar, originating from

Javadihills. It flows through Tiruvannamalai district and South West

boundary of Thimiri block in Vellore district and joins with Palar at

Thirumukkudal in Thiruvallur district.

Pambar is the tributary to Ponnaiyar, originating from Javadi hills.

It flows through South west portion (Kandili Block) in this district and joins

with the river Ponnaiyar. Table 3.2 gives the list of minor river basins falling

within the two major river basins and the area under each river basin.

53

To stabilize the irrigation, two anicuts (Local weir) viz., Palar

anicut and Poiney anicut have been constructed across the river systems of

Palar and Poiney respectively. Palar anicut is situated about 7 km east of

Arcot town and 259 km from the head sources of Palar river. The total length of

the Anicut is 801 m, with four head sluices viz., Mahendravadi, Kaveripakkam

(left flanks), Sakkaranallur and Dusi (right flanks).

Table 3.2 Area under Major and Minor River basins

Sl.

No.

Name of

River Basin

Area in

Km2

Name of Minor river

basin

Area

in Km2

1 Ponnaiyar 892.82 Pambar minor basin 892.82

2 Palar 5027.36 i. Cheyyar Upper

ii. Cheyyar Lower

iii. Agaram

iv. Ambur

v. Kal

vi. Malattar

vii. Koundinyanadhi

viii. K.V. Kuppam

ix. Chittoor

x. Vellore

xi. Ponnai

xii. Walajahpet

xiii. Nandhi

xiv. Kallar

xv. Kaveripakkam

400.25

435.57

490.17

519.08

210.78

268.57

397.03

217.18

171.58

441.99

208.19

531.92

188.28

345.65

201.12

Total Area 5920.18 5920.18

Source: State Ground and Surface Water Resources Data Centre, P.W.D, Chennai-5.

It is the only anicut across Palar river in this district and provides

irrigation to 12,320 ha of ayacut. There are 235 tanks in this system. Poiney

anicut is built across the river Poiney, a tributary of Palar at Ponnai village.

Poniey anicut has two head sluices one on either flank, which irrigates 8,267

ha of ayacut. The length of this anicut is 191 m and there are 129 irrigation

tanks in this system.

54

Vellore district, for all administrative purposes, has been divided

into 7 taluks which are further subdivided into 20 blocks. The administrative

block boundary map of Vellore district is shown in the Figure 3.2.

Figure 3.2 Administrative block boundary map of Vellore district

3.3.2 Climate and Rainfall

Generally, sub-tropical climate prevails over the district. The

temperature rises slowly to maximum in summer months upto May after

which it drops slowly. The mean maximum temperature ranges from 28.20C

to 36.50C and the mean minimum temperature from 17.3

0C to 27.4

0C. The

average rainfall of the district is 953.4 mm. The principal rainy season

commences from the month of June and extends upto the end of December.

Rainfall during Southwest and Northeast monsoon seasons accounts for more

than 75% of the total annual rainfall.

55

3.3.3 Landuse pattern

Classification of land use pattern in Vellore district collected from

Department of Economics and Statistics, Chennai, Government of Tamil

Nadu, is given in Table 3.3. Out of the total geographical area of 5, 92, 018

ha, 38.6% is under net area sown, 14.0% is under land put to non agricultural

use, 13.8% is under fallow, 27.2% is under forest, 4.4% is under barren and

2.0% is under waste land, miscellaneous tree crops and groves.

Table 3.3 Landuse pattern of Vellore district

S.

No.Class Area(ha) Percentage

1 Net area sown 228279 38.6

2 Land put to non agricultural use 82685 14.0

3 Current Fallow 30574 5.2

4 Other Fallow 50825 8.6

5 Forest 161229 27.2

6 Barren and non-culturable land 26054 4.4

7 Cultivable waste 6709 1.1

8 Permanent pastures and other

grazing land

3833 0.6

9 Miscellaneous tree crops & groves

not included in net area sown

1830 0.3

Total 592018 100

3.3.4 Soils

Soil classification of Vellore district, based on the survey

conducted by the Soil Survey and Landuse Organisation of Tamil Nadu

Agricultural Department, indicates six different types of soils as Sandy soil,

Sandy loam, Red loam, Clay, Clayey loam and Black cotton soil. The taluk

wise percentage of distribution of each soil type is given in Table 3.4.

56

Table 3.4 Percentage Distribution of Major Soil Types

S.No. Taluk Sand and

Sandy Loam

Red loam

Soil

Clay and

Clayey

Loam

Black

Cotton

Soil

1 Arakonam 20.0 13.0 59.0 8.0

2 Walajahpet 24.0 12.0 62.0 2.0

3 Arcot 8.0 10.0 54.0 28.0

4 Vellore 11.0 7.0 74.0 8.0

5 Gudiyatham 10.0 33.0 43.0 14.0

6 Vaniyambadi 14.0 11.0 70.0 5.0

7 Tiruppathur 0.0 35.0 57.0 8.0

Source: Joint Director of Agriculture, Vellore-1.

3.3.5 Surface water

The district has 1355 minor irrigation tanks and 604 canals which

act as main source for surface irrigation. Arakonam, Walajah and Tiruppathur

taluks accounts for more than 50 percent of existing tanks in the district. The

district has two major anicuts namely Palar anicut and Poiney anicut

constructed across the river systems of Palar and Poiney respectively. Poiney

is one of the tributaries of Palar. Palar anicut has four head sluices and

provides irrigation to 12,320 ha of ayacut. Poniey anicut has two head sluices

which irrigates 8,267 ha of ayacut.

3.3.6 Groundwater

The irrigation system of this district, often suffers due to inadequate

supply of surface water and depends upon groundwater sources as an

alternative to supplement the surface water source to stabilize the irrigation.

Groundwater potential in all the blocks of Vellore district has been assessed

by Public Works Department, based on the methodology recommended by the

Groundwater Estimation committee (1984). As on January 2005, the

57

assessment indicates, that 16 blocks were categorized as over exploited

(Groundwater development is more than 100%), 2 blocks as Dark

(Groundwater development varies between 90% and 100%) and 2 blocks as

Grey (Groundwater development varies between 70% and 90%), (Source:

State Ground and Surface Water Resources Data Centre, WRO,PWD,

Chennai).

3.3.7 Agriculture

The agricultural data such as land utilization, crop calendar, crop

pattern, crop area and crop yield particulars of the district were collected from

Department of Economics and Statistics, Chennai. The details of cropping

pattern and crop calendar adopted in the district is presented in Figure 3.3.

Paddy is the main crop. Paddy is cultivated in three seasons namely,

Sornawari (April-August), Samba (August-January) and Navarai (December-

April). Pulses and Millets are cultivated as paddy fallows. Groundnut and

Sugarcane are also cultivated in considerable areas.

Figure 3.3 Generalised crop calendar for Vellore district

Sl. Cropping

No pattern Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May

1 Paddy-

Sornawari

2 Paddy -

Samba

3 Paddy-

Navarai

4 Paddy-Pulses/

Groundnut/

Gingelly/

Ragi/

Vegetables

5 Sugarcane

58

3.4 DATA COLLECTED

The data utilized in this study comprises of both spatial and non-

spatial data. The data needed for assessing drought can be grouped into three

categories viz., meteorological, hydrological and agricultural. The data

collected from various departments are detailed below.

3.4.1 Topographic maps

The study area is resulted from the mosaic of 9 topographic maps

of Survey of India (SOI), viz., 57O/4, 57O/12, 57K/12, 57K/16, 57L/6,

57L/7,57L/9,57L/10 and 57L/11 at 1:50,000 scale. From these maps,

information such as location of the villages, water bodies etc., are extracted

and used as input data for database creation. These maps have also been used

for georeferencing of the remotely sensed data.

3.4.2 Meteorological Data

Monthly rainfall data for 15 raingauge stations were collected from

the Department of Economic and Statistics, for the period from 1971-2005.

Climatological data such as temperature, humidity, sun shine, wind velocity,

pan evaporation etc., were collected for the years 1991-2005, from the

Institute for Water Studies (IWS), WRO, PWD, Chennai and India

Meteorological Department, Chennai.

3.4.3 Remote sensing data

The remotely sensed dataset used in this study consists of Indian

Remote Sensing Satellite (IRS) 1C and 1D, Wide Image Field Sensor (WiFS)

data during November 2001 and November 2002 of Samba season. This data

set is available in Centre for Water Resources (CWR), Anna University which

were procured from National Remote Sensing Agency, Hyderabad and is used

to demarcate the area falling under crop land and fallow land in the study area

59

for the Samba season of the years 2001 and 2002. Land use map of Vellore

district was collected from Institute of Remote Sensing, Anna University

which was prepared from IRS-1C LISS III image of October 2000. The

collected land use map was digitized using Arc Map GIS software for

different thematic layers.

3.4.4 Groundwater

The State Surface and Ground Water Resources Data Centre, Water

Resources Organisation in Public Works Department, Government of Tamil

Nadu monitors groundwater in the State and has reported that nearly 90% of

the district is under over exploited and dark regions. Monthly groundwater

fluctuation data for 55 observation wells were collected from State Surface

and Groundwater Resources Data Centre for the period from 1971 to 2005.

3.4.5 Agricultural data

Paddy is the main crop in the study area. Paddy is cultivated in

three seasons namely, Sornawari (April-August), Samba (August-January)

and Navarai (December-April). Pulses and Millets are cultivated as paddy

fallows. Groundnut and Sugarcane are also cultivated in a considerable area.

Details related to crop area for each block in the district were collected from

Department of Economics and Statistics, Vellore.

3.4.6 Census data and block development works

District Census hand book, Vellore district collected from the

Directorate of Census Operations, Chennai, Tamil Nadu has compiled block

and village wise statistics of 2001. This includes the progress of works that

have been taken up under different schemes to provide the basic needs. From

this, information related to amenities such as educational, medical, transport

communications, post offices, banks, power supply etc., are considered to

60

make blocks/villages into group of specific classes. Also the data related to

population and agriculture dependents (cultivators/agricultural labours) were

used to group the blocks into various classes.

3.5 PRELIMINARY ANALYSIS

The meteorological, hydrological and agricultural data collected for

Vellore district has been analysed to study the distribution of rainfall, ground

water status and agricultural practices being adopted. The following sections

describe the preliminary analysis carried out for the study area for identifying

the drought proneness.

3.5.1 Seasonal and Annual Rainfall Analysis

There are 15 raingauge stations distributed over Vellore district. 35

years of monthly rainfall data during 1971 to 2005 were analysed and mean

monthly rainfall values were arrived for all the stations and are presented in

Table 3.5. It was noted from the results that all stations receive high rainfall

during the period of July-December. However, the stations such as

Sholinghur, Arakonam, Kaveripakkam and Panapakkam receive more rainfall

than other stations because of their proximity to the Bay of Bengal. The

average monsoon seasonal and annual values of rainfall for all stations were

analysed and presented in Table 3.6 and also represented in Figure 3.4. The

spatial variation of monsoon rainfall are presented in Figures 3.5 and 3.6. It

can be seen from the above figures that major part of the district receives

considerable amount of rainfall during both the monsoon seasons.

Rainfall during the Northeast monsoon varies spatially from 263.3

mm at Jolarpet to 539.7 mm at Arakonam. During the Southwest monsoon, it

varies spatially from 291.9 mm at Sholinghur to 458.2 mm at Kaveripakkam.

The annual rainfall ranges from 787.3 mm at Alangayam to 1124.1 mm at

Arakonam.

61

Table 3.5 Mean monthly rainfall of Vellore district

S.

No.Name of Station

Mean monthly rainfall (mm)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

1 Vellore 7.0 10.1 9.5 27.9 74.6 76.1 121.6 131.2 179.3 166.9 152.6 75.4

2 Ambur 3.0 5.7 7.9 20.8 75.8 67.4 87.6 108.5 168.4 172.8 93.2 42.2

3 Gudiyatham 4.5 6.4 7.3 20.2 84.2 79.2 115.8 119.4 170.2 157.0 119.6 57.6

4 Tirupathur 1.8 6.0 9.1 31.3 83.2 51.9 104.1 118.6 196.3 164.3 75.1 38.7

5 Vaniyambadi 3.3 3.9 6.2 23.7 67.6 65.6 81.2 103.9 191.0 160.6 80.7 45.1

6 Walajahpet 8.0 6.7 9.7 17.0 58.5 60.8 127.0 129.5 168.1 172.9 172.0 78.0

7 Sholinghur 9.7 6.0 6.9 16.7 49.7 50.2 99.5 104.6 137.2 218.3 140.9 72.7

8 Ranipet 8.8 7.5 11.4 23.7 71.4 68.5 110.5 135.7 180.9 175.0 159.0 79.8

9 Palar Anicut 7.2 5.4 11.2 20.4 60.5 62.6 106.1 151.8 199.1 182.4 150.6 138.1

10 Ponnai Anicut 5.4 9.1 11.3 23.0 73.9 79.2 140.0 124.7 171.9 176.7 164.1 66.1

11 Arakonam 15.9 10.2 10.3 16.9 48.3 70.4 120.2 136.7 155.5 203.4 224.4 111.9

12 Kaveripakkam 8.0 4.9 7.0 17.2 55.9 76.0 101.9 123.3 157.0 159.7 165.1 82.4

13 Panapakkam 11.2 7.7 7.0 19.0 56.6 70.6 120.0 203.6 147.9 174.5 196.0 97.1

14 Alangayam 4.0 7.3 9.9 37.4 67.0 66.7 92.4 101.5 142.3 134.6 87.6 49.7

15 Jolarpet 3.6 3.8 6.7 38.8 97.0 62.2 108.6 121.0 197.1 151.6 76.5 35.2

62

0

200

400

600

800

1000

1200

Ve

llo

re

Am

bu

r

Gu

diy

ath

am

Tir

up

ath

ur

Va

niy

am

ba

di

Wa

laja

hp

et

Sh

olin

gh

ur

Ra

nip

et

Pa

lar

An

icu

t

Po

nn

ai A

nic

ut

Ara

ko

na

m

Ka

ve

rip

akka

m

Pa

na

pa

kka

m

Ala

ng

aya

m

Jo

larp

et

Raingauge Station

Ra

infa

ll (m

m)

Annual Northeast Southwest

Table 3.6 Average Annual and Seasonal rainfall in Vellore district

Sl.No. Name of StationAnnual

rainfall(mm)

Seasonal rainfall (mm)

Northeast Southwest

1 Vellore 1032.2 394.9 386.6

2 Ambur 853.3 308.2 344.4

3 Gudiyatham 969.0 344.1 368.8

4 Tirupathur 880.5 278.1 366.8

5 Vaniyambadi 865.3 294.7 360.5

6 Walajahpet 1008.1 422.9 358.4

7 Sholinghur 912.3 431.9 291.9

8 Ranipet 1032.2 413.8 385.1

9 Palar Anicut 1095.4 471.0 413.5

10 Ponnai Anicut 1045.4 406.9 375.8

11 Arakonam 1124.1 539.7 362.6

12 Kaveripakkam 958.3 407.2 458.2

13 Panapakkam 1111.2 467.6 422.2

14 Alangayam 787.3 271.9 310.6

15 Jolarpet 902.1 263.3 380.3

Figure 3.4 Variation of monsoon seasonal rainfall in Vellore district

63

Figure 3.5 Spatial distribution of Northeast monsoon rainfall in study area

Figure 3.6 Spatial distribution of Southwest monsoon rainfall in study area

64

The analysis for Northeast monsoon shows that nearly 50% of the

district gets rainfall varying from 265 to 365 mm. The eastern portion of the

district which includes the blocks like Arakonam, Nemili, Kaveripakkam,

Arcot and Thimiri receive substantial amount of rainfall because of their

proximity to the Bay of Bengal. Western portion of the district, which

includes Kandili, Alangayam, Tiruppathur, Jolarpet, Natrampalli, Pernamput

and Madhanur are receiving low rainfall. During the Southwest monsoon

period, major portion of the district receives rainfall from 350 mm to 400 mm.

The blocks like Thimiri, Arcot and parts of Kaveripakkam and Nemili receive

considerable rainfall. Alangayam, parts of Tiruppathur, Madhanur,

Pernumput, Anaicut, Kaveripakkam and Sholinghur receive low rainfall

during this season.

3.5.2 Rainfall analysis for Crop Seasons

The main crop seasons in the Vellore district are Sornawari (April-

August), Samba (August-January) and Navarai (December-April). The crop

seasonal rainfall for all the stations were analysed and presented in Table 3.7

and are also represented in Figure 3.7. The average rainfall is 690.1 mm,

110.6 mm and 395.8 mm during Samba, Navarai and Sornawari seasons

respectively. The analysis indicates that the mean seasonal rainfall values for

the district during Samba season are more compared to the Navarai and

Sornawari season rainfall values. Samba crop season which is the main crop

season in the district is influenced by both Northeast as well as the Southwest

monsoons. During this season, nearly 50% of the district receives rainfall

varying from 660 to 860 mm. The spatial variation of rainfall for Samba

season was analysed and is shown in Figure 3.8. It is observed from the

analysis that the blocks like Arakonam, Nemili, Kaveripakkam, Arcot,

Thimiri, Walajahpet, Sholinghur, Katpadi, Vellore and parts of Kaniyambadi,

K.V.Kuppam receive substantial amount of rainfall. Alangayam, Jolarpet,

Natrampalli and parts of Tiruppathur, Madhanur receive considerably low

amount of rainfall.

65

Navarai crop season receives rainfall during Winter and Summer

seasons. Out of the three crop seasons prevailing in the district, Navarai

season receives low rainfall. Figure 3.9 shows the spatial variation of rainfall

for Navarai season. It is observed from the analysis that nearly 75% of the

district significantly receives low rainfall ranging from 75 to 115 mm. Entire

western portion of the district receive low rainfall. Eastern portion of the

district which includes blocks like Arakonam, Nemili, Thimiri and Arcot

receives high rainfall. Sornawari crop season is influenced by Southwest

monsoon and during this season, major portion of the district gets rainfall

varying from 380 to 470 mm. Figure 3.10 shows the spatial variation of

Sornawari crop seasonal rainfall.

Table 3.7 Average crop seasonal rainfall in Vellore district

Sl.NO. Name of StationSornawari Samba Navarai

(Apr-Aug) (Aug-Jan) (Dec-Apr)

1 Vellore 431.4 712.4 122.0

2 Ambur 360.2 591.2 75.8

3 Gudiyatham 418.7 632.7 93.7

4 Tirupathur 389.2 596.4 82.8

5 Vaniyambadi 341.9 571.0 71.3

6 Walajahpet 392.8 736.5 112.2

7 Sholinghur 320.6 693.0 103.9

8 Ranipet 409.8 747.9 123.8

9 Palar Anicut 401.3 836.4 175.2

10 Ponnai Anicut 440.8 714.3 111.0

11 Arakonam 392.5 863.6 149.1

12 Kaveripakkam 374.2 702.9 110.8

13 Panapakkam 469.8 841.0 136.2

14 Alangayam 365.1 523.8 106.3

15 Jolarpet 427.6 588.4 85.1

66

0

100

200

300

400

500

600

700

800

900

1000

Vello

re

Am

bur

Gudiy

ath

am

Tirupath

ur

Vaniy

am

badi

Wala

jahpet

Sholin

ghur

Ranip

et

Pala

r A

nic

ut

Ponnai A

nic

ut

Ara

konam

Kaveri

pakkam

Panapakkam

Ala

ngayam

Jola

rpet

Raingauge Stations

Rain

fall(m

m)

Sornawari Samba Navarai

Figure 3.7 Variation of crop seasonal rainfall in Vellore district

Figure 3.8 Spatial distribution of Samba seasonal rainfall in study area

67

Figure 3.9 Spatial distribution of Navarai seasonal rainfall in study area

Figure 3.10 Spatial distribution of Sornawari seasonal rainfall in study area

68

It is observed from the analysis that the blocks like Natrampalli,

Alangayam and parts of Madhanur, Pernumput, Kaveripakkam and

Sholinghur receive low rainfall.

The blocks like Natrampalli, Tiruppathur, Madhanur, Pernamput,

Jolarpet receive low rainfall and the blocks like Nemili, Arakonam, Thimiri

and Arcot receive good rainfall in all the three crop seasons.

3.5.3 Groundwater Analysis

Palar is the only major river that flows through the district. During

the major part in the year, the river is dry and the flow is limited to a shorter

period during the Northeast monsoon. Hence, groundwater plays a major role

for irrigation in the district. The groundwater fluctuation during the three crop

seasons was analysed for each block and the results are presented in Table

3.8. Groundwater level fluctuation varies highly during Samba season from

2.33 m in Katpadi and Madhanur to 6.88 m in Jolarpet. During Navarai

season, the spatial variation is ranging from 1.42 m in Madhanur to 5.69 m in

Jolarpet. The variation during Sornawari season ranges from 1.15 m in

Tiruppathur to 2.51 m in Walajahpet. Figure 3.11 shows the variation of

Groundwater fluctuation for each block. It is observed from the figure that

water level fluctuation is high in blocks namely Walajahpet, Sholinghur,

Acrot, Thimiri, Vellore, Pernumput, Natrampalli and Jolarpet during all the

three crop seasons. In blocks such as Nemili, Arakonam, Madhanur, Katpadi

and Tiruppathur, the groundwater fluctuation is less compared to other blocks.

It is observed that groundwater level fluctuation is higher in Samba season

during which first paddy crop is grown. Even in Navarai season, there is

considerable fluctuation during which second paddy crop is grown. In

Sornawari season, the water level fluctuation is less compared to other two

seasons during which only dry crops are grown.

69

Table 3.8 Average crop seasonal groundwater fluctuation in Vellore district

Sl.No.Name of

block

Name of

Village (depth below G.L. (m))*

Crop seasonal

Groundwater

fluctuation (m)

(1) (2) (3)

1 Alangayam Alangayam (11.68), Ambur(18.39) 1.9 3.77 2.34

2 Anaicut

Perumugai(10.92), Karadikudi(10.74),

Pinnathurai(9.16) 2.41 4.76 2.95

3 Arakonam Senthamangalam(10.49), Ayarpadi(8.71) 1.82 3.08 2.1

4 Arcot

Maruthuvambadi(16.47), Melpalandai(9.10),

Ammur(15.45) 2.36 5.1 3.12

5 Gudiyatham Gudiyatham(12.08), 2.3 4.32 2.45

6 Jolarpet Vaniyambadi(9.98),S.Palli(14.6),Kandili(11.8) 2.36 6.88 5.69

7 K.V.Kuppam Kailasagiri(13.07), Pallalakuppam(21.20) 1.97 4.98 2.65

8 Kandili

Pakkiri (11.54),Tharka(11.45), H.Puram(12.56)

Andiyappanur(10.30) 1.31 3.86 2.69

9 Kaniyambadi

Mettupalayam(18.03),

Guruvarajapalayam(14.49), Pallikonda(10.60) 1.35 3.86 2.78

10 Katpadi Pernambut(14.43), Arumparuthi(11.00) 1.3 2.33 1.92

11 Kaveripakkam Kaveripakkam(8.43), Athipattu(6.93) 2.23 4.05 3.26

12 Madhanur Usur(11.92), Thuthikadu(10.02), Poigai(13.95) 1.25 2.33 1.42

13 Natrampalli Velakalnatham(13.45), Natrampalli(17.37) 2.1 6.02 5.12

14 Nemili

Kilveeranam(12.50), Mangammapettai(13.64),

Nehru Nagar((10.79) 1.95 3.19 2.21

15 Pernamput

Asnampet(16.93),Minnur(13.86), Vengili(11.9)

Kallapadi Mottur(23.75), Modikuppam(17.98) 2.04 4.53 3.08

16 Sholinghur

Ponnai(11.90), Sholinghur(13.90),

Thalangai(18.98), Sumaithangi(13.50) 2.44 4.52 3.72

17 Thimiri

Kalavai(10.69), Kaniyanur(13.75),Pudur(8.04),

T.Pakkam(18.33), Ayilam(12.54), Varahur 2.5 4.61 2.82

18 Tiruppathur Thoranampatti(10.29) 1.15 2.99 2.18

19 Vellore Vallam(11.27), Vellore water works(12.50) 2.1 6.03 4.39

20 Walajahpet Thengal(9.52), Palar Anaicut(8.01) 2.51 6.01 4.31

Note: (1) Sornawari (Apr-Aug) (2) Samba (Aug-Jan) (3) Navarai (Dec-Apr)

* All are open wells.

70

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Figure 3.11 Variation of groundwater fluctuation in Vellore district

3.6 DPAP IN STUDY AREA

As on November, 2008, out of the total number of 20 blocks in

Vellore district 6 blocks namely Alangayam, Kaniyambadi, Kandili, Katpadi,

Thimiri and Vellore are covered under Drought Prone Areas Programme.

Steady increase in the number of blocks covered under DPAP indicates that

the incidences of droughts are increasing over the years, which require

immediate attention through drought analysis and studies.

The present study is aimed in developing a drought assessment

procedure in meteorological and agricultural contexts and also to develop an

integrated drought severity assessment procedure for a drought prone Vellore

district.