Desertification Monitoring in China. Wang Junhou China National Desertification Monitoring Center July, 2012

Transcription

1 Desertification Monitoring in China Wang Junhou China National Desertification Monitoring Center July, 2012

2 Content National desertification monitoring Desertification annual trend monitoring Sand and dust storm monitoring and assessment Application of monitoring results

3 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.

4 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.

5 1)Monitoring methods With integration of field surveys and remote sensing, Mapping plot and calculating relative data.

6 The framework of monitoring on national level RS image data Image calibration Adjusted basic map Site built interpret. signs and supplementary data Man- computer interactive subcompment zonation PDA input or card recording Site compartment border verification and factor survey Subcompartment attribute data input Data logical checking Factor revision Quality control All accepted? N Y Data statistical analysis Diagrams and tables The monitoring report

7 Use computer to classify the map plots Geographic border line

8 field survey to get the value of each indicators

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

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

11 2)The status of national desertification Desertification By the end of 2009, the total desertified land area in China is 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 million square kilometers,making up 18.03% of the national territory in 902 counties of 30 provinces.

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13 3)The dynamic changes Desertification The dynamic changes of desertified land area (million square kilometer) year area 面积 5 Km ( 万平方公里 2 ) 年度

14 Sandification 10 面积 5 ( Km 万平方公里 2 ) The dynamic changes of desertified land area (million square kilometer) year area

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16 The degree of desertification is decreasing ( ) 第三次 2009 第四次 The area of light degree desertified land increased million ha 第三次 2009 第四次 The area of medium degree desertified land decreased million ha 第三次第四次 The area of severe degree desertified land decreased 0.68 million ha 重度荒漠化土地减少 万公顷 极重度荒漠化土地减少 万公顷 第三次第四次 The area of extremely degree desertified land decreased million ha

17 The vegetation is getting better( ) The vegetation coverage increasing obviously 盖度小于 10% 的沙化土地减少 万公顷 第三次第四次第三次第四次 The area of low coverage vegetation(0-30%) is decreasing The area of high coverage vegetation(>30%) in increasing

18 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

19 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.

20 Statistics and Automatic generation the database

21 2. Focus monitoring Since 1999, more than 50 key thematic studies has be completed. 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.

22 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

23 2)Case studies Average temperature and difference with average value curve Climate change in the past 50 years in the desertification areas in desertification area. Temperature change Precipitation and difference with average value curve Precipitation change Arid index change Arid index and difference with average value curve

24 Annual control areas of soil loss in study areas Change trend of soil erosion in the past 5 years in arid regions: area of soil and water erosion was hm 2 in the year Compared with 1999, area decreased by hm 2, about 7.39% of total areas. province 合计 qinghai gansu ningxia Inner Mongoli a shaanxi shanxi total

25 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, semishifting 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%.

26 1987 shifting sandy land Semi fixing sandy land fixing sandy land 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.

27 Maqu county wind-erosion 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.

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 28

29 3. Positioned monitoring 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.

30 1)Station distribution 呼伦贝尔站 阜康站 乌兰敖都站 策勒站 张掖站 沙珠玉站 民勤站 磴口站鄂尔多斯站 盐池站 固原站 多伦站宣化站 密云水库站怀仁站榆林站 奈曼站

31 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

32 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.

33 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.

34 生物量 (g/m2) 植被高度 (cm) 植被盖度 (%) 4)Main results 年 2007 年 Vegetation coverage comparison of 2008 with 阜年 2007 康年 张掖 民勤 榆林 怀仁 宣化 多伦 乌兰敖都 西部地区中部地区东部地区 奈曼 Vegetation height comparison of 2008 with 阜康 张掖 民勤 榆林 怀仁 宣化 800 多伦 乌兰敖都 奈曼 700 西部地区 中部地区 东部地区 2008 年 2007 年 Biomass comparison of 2008 with 阜康 张掖 榆林 怀仁 宣化 多伦 乌兰敖都 西部地区中部地区东部地区 奈曼

35 Ⅱ. Annual Trend Monitoring Field sampling survey Remote sensing of vegetation growth Precipitation monitoring by remote sensing

36 Methodology and technology Field survey Field sampling survey trends NDVI Remote sensing Precipititaion Soil moisture index annual dynamic 36

37 1. Field sampling survey The sampling lines distribution

38 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

39 field survey Field survey indicators covered types of desertified land, land use, soil, vegetation, control measures, the causes of change.

40 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.

41 NDVI map of May to October in 年 5 月 2008 年 6 月 2008 年 7 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 8 月 2008 年 9 月 2008 年 10 月

42 NDVI difference value of May-October in 2008 to the same periods in 2007

43 3. Precipitation monitoring by remote sensing 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.

44 Precipitation map in 2008 (unit: mm)

45 Difference value map between 2007 and 2008

46 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,

47 植被盖度变化 NDVI 变化 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 = x R 2 = y = x R 2 = 降水变化 降水量变化 Correlation between vegetation coverage and precipitation, Correlation between NDVI and precipitation,

48 Ⅲ. Monitoring and Assessment of Sand and Dust Storm Methodology and technology Remote sensing Local information desertification Social and economic Extract dust storm information Phenology database intensity path extent Local status damage crops Report of Assessment

49 Sand storm information processing Remote sensing data receiving Sand storm information acquisition Sand storm image enhancement Image transfer overlay geography data sand storm image

50 Satellite data receiving system Data source: NOAA-12, NOAA-16, NOAA- 17, NOAA-18, FY-1D, MODIS/TERRA, MODIS/AQUA etc.

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

52 Field data real-time receiving system A mobile phone short message receive system has been established to obtain and transform real-time information and data of sand and dust storm Information processing Real-time field information received by local people User inquiry

53 Sand storm observation plots have been established in north west, north and northeast parts of China. The observers send the realtime data of sand storm to National Desertification Monitoring Center, in terms of visibility, wind velocity and crop damage. Sender Name 李亚娟 Sandstorm SM Platform Message 今天银川有 5 到 6 级风, 有浮尘 Time 2008 年 2 月 29 日 11:23: 闫述兵 今天二连浩特有沙尘暴, 能见度 100 米, 严重影响交通 2008 年 2 月 29 日 13:17: 高平伟 乌拉特中旗风力 5-6 级, 有沙尘, 能见度 150 米 2008 年 2 月 29 日 11:20:37

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55 The sources of data The desertification assessment Land use Vegetation coverage Vegetation type Socio-economic condition

56 Sand storm disaster assessment Overlay land use, vegetation coverage, crop and economic tree crops, social and economic data etc.

57 Assessment report of sand storm disaster 省名 县名 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 甘肃 共 22 个县 金塔 高台 肃南 临泽 民勤 山丹 永昌县 民乐 古浪 天祝

58 Ⅳ. Application of monitoring results 1.Policy decision-making and large projects planning.

59 2.Provide supporting materials for local desertification control projects.

60 3. Implement UNCCD 4.International cooperation projects

61 THANKS!