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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!