Desertification Monitoring in

China

Wang Junhou

China National Desertification Monitoring Center July, 2012

Content

National desertification monitoring

Desertification annual trend monitoring

Sand and dust storm monitoring and assessment

Application of monitoring results

Ⅰ. China national desertification monitoring

1.Large Scale monitoring on the national level in detail • All of the country

• Every 5 years for one time monitoring

• Status and change of desertification and sandification

• Causes and achievement for combating desertification

2. Focus monitoring • Some important and sensitive regions(bright or hot point),

• more detail survey and analyze causes

3.Positioned monitoring • Long time series of observations

• study mechanism of desertification

• put forward control measures.

1.Macro monitoring on national level

To implement UNCCD

To supply the data and information to the government decision-making.

The desertification monitoring systems has been set up

4 times on national desertification monitoring have been conducted in 1994, 1999,

2004 and 2009 .

1)Monitoring methods

• With integration of field surveys and remote sensing,

• Mapping plot and calculating relative data.

RS image data Adjusted basic map

Image calibration Site built interpret. signs

and supplementary data

Man- computer interactive subcompment zonation

Site compartment border verification and factor survey

Subcompartment

attribute data input

Data logical checking

All accepted ?

Factor revision

N

Data statistical analysis

Y

The monitoring report

Diagrams and tables

Qu

ality

co

ntro

l

PD

A in

pu

t or c

ard

re

co

rdin

g

The framework of monitoring on national level

• Use computer to classify the map plots

• Geographic border line

field survey to get the value of each indicators

After finishing field survey, generating a Geo-database by linking each plot`s attributes to the shape file.

finally we use GIS to calculate areas, analyze the result and thematic mapping.

2)The status of national desertification

•Desertification

By the end of 2009, the total desertified

land area in China is 262.3713 million

square kilometers，making up 27.33%

of the national territory in 508 counties

of 18 provinces.

•Sandification

By the end of 2009, the total sandified land

area in China is 173.1081 million square

kilometers，making up 18.03% of the

national territory in 902 counties of 30

provinces.

3)The dynamic changes

•Desertification

258

260

262

264

266

268

年度

面积(万平方公里)

1994 1999 2004 2009

The dynamic changes of desertified land area

（million square kilometer)

year 1994 1999 2004 2009

area 262.23 267.41 263.62 262.37

105 Km2

•Sandification

166

167

168

169

170

171

172

173

174

175

面积(万平方公里)

year 1994 1999 2004 2009

area 168.85 174.31 173.97 173.11

The dynamic changes of desertified land area

（million square kilometer)

105 Km2

1994 1999 2004 2009

2004

2009

The area of light degree desertified land

increased 3.4653 million ha

3782.95

4129.48

3600.00

3700.00

3800.00

3900.00

4000.00

4100.00

4200.00

第三次 第四次

•The degree of desertification is decreasing (2004-2009)

5940.96

5772.00

5650.00

5700.00

5750.00

5800.00

5850.00

5900.00

5950.00

6000.00

第三次 第四次

3354.60

3286.60

3240.00

3260.00

3280.00

3300.00

3320.00

3340.00

3360.00

第三次 第四次

重度荒漠化土地减少68.00万公顷

极重度荒漠化土地减少234.12万公顷

5366.21

5132.08

第三次 第四次

The area of medium degree desertified land

decreased 1.6859 million ha

The area of severe degree desertified land

decreased 0.68 million ha The area of extremely degree desertified

land decreased 2.3412 million ha

2004 2009

2004 2009 2004 2009

2004 2009

The vegetation is getting better(2004-2009)

10094.56

7724.58

第三次 第四次

盖度小于10%的沙化土地减少2369.98万公顷

1004.56

1084.75

第三次 第四次

The area of high coverage

vegetation(>30%) in increasing

The area of low coverage

vegetation(0-30%) is decreasing

•The vegetation coverage increasing obviously

2004 2009 2004 2009

4). Established desertification monitoring information system

Main functions of the system:

• Quick inquiry of map layers

• Statistics of data

• Statistics of the selected areas

• Mapping of thematic topics

专题图制作功能

中国荒漠化分布图(2004)

Thematic mapping: mapping of

types, degree, vegetation

coverage, land use and

vegetation type of desertification

and sandification in selected

administrative regions.

Statistics and Automatic generation the database

2. Focus monitoring

•Some important and sensitive regions (bright or hot point)

•More detail survey

•Causes analysis of desertification causes on natural and human being

•Including: climate change,

policies and regulations,

land use ,

water use,

ecological construction,

land management

land degradation and desertification dynamic change studies.

Since 1999, more than 50 key thematic studies has be

completed.

1) Monitoring subjects

• Climate change analysis in desertification regions

• Analysis of effects of related national policies

• Natural and human activities analysis as the causes of

desertification

• Dynamic change analysis of grassland degradation, soil erosion

and salinization

• Ecological benefits analysis of water resources allocation of

inland rivers.

• Cause analysis of dynamic changes of the desertified regions

Climate change in the past 50

years in the desertification

areas in desertification area.

•Temperature change

•Precipitation change

•Arid index change

Precipitation and difference with average value curve

Arid index and difference with average value curve

Average temperature and difference with average value curve

2）Case studies

Change trend of soil

erosion in the past 5 years

in arid regions:

area of soil and water

erosion was

5136.01×104hm2 in the

year 2003.

Compared with 1999, area

decreased by

409.91×104hm2 , about

7.39% of total areas.

province 2000 2001 2002 2003 合计

qinghai 3.9 6.91 8.3 1.98 21.09

gansu 35.07 30.87 30.82 31.45 128.21

ningxia 10.76 12.9 13.6 13.6 50.86

Inner

Mongoli

a

60.49 57.62 62.7 61.2 242.01

shaanxi 50.98 70.71 72.45 71.12 265.26

shanxi 33.33 38.11 38.4 38.5 148.34

total 194.5

3

217.12 226.27 217.85 855.77

Annual control areas of soil loss in study areas

Dynamic change of sandified

land of Horqin Sandy Land，in Inner Mongolia from 2001 to

2004

Compared with the results of 2001,

the shifting sandy land in 2004

decreased by 5907 Ha, semi-

shifting sandy land decreased by

7042 Ha, and fixed sandy land

increased by 14,340 Ha , forest

coverage increased by 1.63%, and

vegetation coverage in grassland

increased by 15%.

1987

1999

2004

Otindag Sandy Land :

Compared with 1987, the

acreage of shifting sandy

land in 1999 increased by

5392 ha;

Compared with 1999, the

acreage of shifting sandy

land in 2004 decreased by

8189ha, and fixing sandy

land increased by 62764ha.

shifting sandy land

fixing sandy land

Semi fixing sandy land

Grassland dynamic change in Maqu county of Gansu province: wind-eroded land

encroached to the margin of wetland. Compared with 1999, wind-eroded grassland

area in 2004 increased by 1057 ha with average annual increase of 211ha.

Maqu county wind-erosion

28

• The regions where situation was getting better and is

continuously improving

• The regions where desertification used to be expanding but is

now getting better

• The regions where desertification was expanding dramatically

and are now is slowing down

• The region where desertification was expanding and now is

speeding up

20 observational stations were established in different

biophysical and social-economic regions. Some monitoring

subjects were conducted: long-term observation; collection

of data of desertification; study on cause, development and

change mechanism of desertification; study on relationship of

soil, vegetation, climate and social-economic factors with

desertification. These shall help provide supporting materials

for policy decision-making.

3. Positioned monitoring

乌兰敖都站

多伦站

怀仁站

榆林站

磴口站

盐池站

固原站

民勤站

呼伦贝尔站

张掖站

奈曼站

宣化站

沙珠玉站

鄂尔多斯站 密云水库站

阜康站

策勒站

1）Station distribution

2）Objectives of positioned monitoring

• Based on monitoring results of vegetation, soil and ground water,

ground surface situation are assessed to provide supporting

materials for sand storm forecasting analysis.

• Based on field survey of vegetation, relationship of NDVI and

vegetation coverage is established to calculate vegetation

coverage change.

• Based on monitoring results of vegetation, soil and ground water,

annual desertified land trends are analyzed

3) Monitoring subjects

• Meteorological indicators ：precipitation, evaporation,

continuous rainfall-free days, average temperature, wind

velocity, wind direction, days of strong wind, dust days, sand

winnowing days, sand storm days

• Vegetation：types, growth, coverage, height, density and

biomass. 50 Sampling plots for survey once month from

May to September.

• Soil ：soil moisture ( 0-10cm) ,observation at the same time

with vegetation.

• Ground water：10 wells were observed in farmland,

grassland closure and immigration regions . Time : March to

October

• sand storm monitoring：from March to May

• Socio-economic data ：agriculture, forestry, livestock and

economic data

• Subject researches ：based on special situations in each

station, thematic subjects related to controlling desertification

can be researched.

4）Main results

0

10

20

30

40

50

60

阜康

张掖

民勤

榆林

怀仁

宣化

多伦

乌兰敖都

奈曼

西部地区 中部地区 东部地区

植被

盖度

（%）

2008年

2007年

0

50

100

150

200

250

阜康

张掖

民勤

榆林

怀仁

宣化

多伦

乌兰敖都

奈曼

西部地区 中部地区 东部地区

植被

高度

（cm

）

2008年

2007年

0

100

200

300

400

500

600

700

800

阜康

张掖

榆林

怀仁

宣化

多伦

乌兰敖都

奈曼

西部地区 中部地区 东部地区

生物

量（

g/m2

）

2008年2007年

Vegetation coverage

comparison of 2008

with 2007

Vegetation height

comparison of 2008

with 2007

Biomass comparison of

2008 with 2007

Field sampling survey

Remote sensing of vegetation growth

Precipitation monitoring by remote sensing

Ⅱ. Annual Trend Monitoring

36

………

Field

surv

ey

Field sampling survey

Rem

ote sen

sing

NDVI

Precipititaion

Soil moisture index

trends

Methodology and technology

annual dynamic

The sampling lines distribution

1. Field sampling survey

Sampling lines position and reposition

Position:metal patches to be put in

under surface 30 cm deep at start and

end point.

Reposition: by metal detector and GPS

field survey

Field survey indicators covered types of desertified land, land use,

soil, vegetation, control measures, the causes of change.

2. Remote sensing of vegetation growth

Based on MODIS data, NDVI of multi-time scale such as a

period of ten days, one month and four months was calculated

to obtain the dynamic change trends at national or regional

levels.

NDVI map of May to October in 2008

2008年 8月

2007年7月我国陆地植被指数图

2008年9月我国陆地植被指数图

2008年10月我国陆地植被指数图

2008年 5月 2008年 6月 2008年 7月

2008年 9月 2008年10月

NDVI difference value of May-October in 2008

to the same periods in 2007

Based on satellite data of FY and calibration of station

observation data, precipitation map of multi-time

scale( period of ten days, one month, four months, one

year) was conducted by energy water balance systems to

obtain dynamic change of precipitation at national or

regional levels.

3. Precipitation monitoring by remote sensing

Precipitation map in 2008 (unit: mm)

Difference value map between 2007 and 2008

4. Integrated assessment of desertification

vegetation growth assessment

By integrating with overlaying of field survey and remote

sensing, vegetation growth is assessed comprehensively.

Vegetation assessment in northern China, 2007-2008

Causes of vegetation change

Based on precipitation monitoring results, causes of vegetation change

was assessed and analyzed by correlation of vegetation coverage of field

survey and NDVI

y = 0.2568x + 0.7299

R2 = 0.6408

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

降水变化

植被盖度变化

Correlation between vegetation

coverage and precipitation, 2007-2008

y = 0.2589x + 0.781

R2 = 0.7195

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

1.20

1.25

1.30

0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80

降水量变化

NDVI变化

Correlation between NDVI and

precipitation, 2007-2008

Ⅲ. Monitoring and Assessment of Sand

and Dust Storm

Methodology and technology

Report of Assessment

Extract dust storm information

Local information desertification

Remote sensing

Social and economic

Phenology database

intensity path extent

damage crops Local status ……

Sand storm information processing

Remote sensing data receiving

Sand storm information acquisition

Sand storm image enhancement

Image transfer

overlay geography data

sand storm image

Data source: NOAA-12 , NOAA-16, NOAA-

17, NOAA-18, FY-1D, MODIS/TERRA,

MODIS/AQUA etc.

Satellite data receiving system

Satellite image of sand storm from Feb,29 to March 2, 2008

Field data real-time receiving system

Real-time field information received by local people

Information processing

User inquiry

A mobile phone short message receive system has been

established to obtain and transform real-time information

and data of sand and dust storm

2008年2月29日11：20：37

乌拉特中旗风力5-6级，有沙尘，能见度150米

高平伟 139047869

82

2008年2月29日13：17：14

今天二连浩特有沙尘暴，能见度100米，严重影响交通

闫述兵 139479145

61

2008年2月29日11：23：55

今天银川有5到6级风，有浮尘

李亚娟 139095978

54

Time Message Name Sender

Sandstorm SM Platform

Sand storm observation

plots have been established

in north west, north and

northeast parts of China.

The observers send the real-

time data of sand storm to

National Desertification

Monitoring Center, in terms

of visibility, wind velocity

and crop damage.

The desertification assessment

Land use

Vegetation coverage

Vegetation type

Socio-economic condition

The sources of data

Overlay land use,

vegetation coverage, crop

and economic tree crops ,

social and economic data

etc.

…………………

Sand storm disaster assessment

Assessment report of sand storm disaster

总人口 土地面积 耕地面积 林地面积 园地面积 草地面积

万人 平方公里 公顷 公顷 公顷 公顷

共10个省 共416个县 14568 1063539.4 16386953.4 8127728.2 1645754.4 36054559甘肃 共22个县 397.9 141551.1 587939.6 838350 63349.4 5458844.3

金塔 11.3 16526.2 16493.8 10100.2 2585.2 22474.1高台 14.9 2279.9 21266.1 11591.5 5266.7 63476.3肃南 4 23258 3033 211012 67 1280447临泽 14 2755 15800 13399 5813 96435民勤 28 16016 62420 49520 2673 321128山丹 17.9 6652.9 37522.9 46067 2618.2 307892.9永昌县 24 2659 38667 45765 1653 170057民乐 17.4 2195.6 46710.7 32749.1 6177.8 74680古浪 36 5287 74307 14268 2760 217767天祝 9 2934.1 10059.5 768.6 0 159972.5

省名 县名

Ⅳ. Application of monitoring results

1.Policy decision-making and large projects planning.

2.Provide supporting materials for local desertification control projects.

3. Implement UNCCD

4.International cooperation projects

THANKS！