Irrigated Areas of China based on Satellite Sensors and National Statistics: Issues and Way forward from Global Irrigated ...
<ul><li>The issues: </li></ul><ul><ul><li>Irrigated areas from remote sensing </li></ul></ul><ul><ul><li>Irrigated areas f...
1. Irrigated areas from Remote Sensing
1. Irrigated areas from Remote Sensing  Global irrigated area map China irrigated area map TAAI* AIA* Rainfed area Total c...
2. Irrigated areas from national statistics
2. Irrigated areas from national statistics the Ministry of  Land and Resources  the Ministry of  Water Resources the Mini...
2. Irrigated areas from national statistics <ul><li>Field measurements for all units </li></ul><ul><li>Summarized @ variou...
2. Irrigated areas from national statistics Total crop land areas decrease Effective irrigated areas increase Source:  Sta...
3. GIAM China vs. national statistics:  the comparison
3.GIAM China vs. national statistics:  the comparison Source: CHINA NATURAL RESOURCES DATABASE, CAS 129,205,000 N.A. N.A. ...
3.GIAM China vs. national statistics:  the comparison Source: CHINA NATURAL RESOURCES DATABASE, CAS
4. GIAM China vs. national statistics:  Understanding the differences
4.1  Definition Issues 4. Understanding the differences
4. Understanding the differences <ul><li>Irrigated area – the definition </li></ul><ul><ul><li>Irrigated area </li></ul></...
4.2  Limitation in National Statistics 4. Understanding the differences
<ul><li>Advantages: </li></ul><ul><li>Accurate </li></ul><ul><li>Detailed </li></ul><ul><li>Disadvantages: </li></ul><ul><...
<ul><li>Limitation of national statistics </li></ul>4. Understanding the differences <ul><li>Inconsistent area units  mu  ...
<ul><li>Decrease of large irrigation system command area </li></ul>4. Understanding the differences Zhanghe Irrigation sys...
Irrigated,  small reservoirs , Rice, Single crop Irrigated,  groundwater , rice, double crop Irrigated,  small tanks , Ric...
4. Understanding the differences <ul><li>Informal irrigation missing in national statistics </li></ul><ul><li>Increase of ...
4.3  Limitation in GIAM 4. Understanding the differences
4. Understanding the differences local fractions Global fractions Global irrigated area fractions (IAF G ) are computed fo...
<ul><li>Refinement of GIAM – Resolution effects </li></ul>MODIS 500 m Landsat 30 m AVHRR 10 km Syr Darya River Basin, Cent...
<ul><li>Refinement of GIAM – Resolution effects </li></ul>AVHRR 10 km MODIS 500 M LANDSAT 30 M Ruhuna river basin, Sri Lan...
Misrepresentation of minimum mapping unit 10 km 10 km AVHRR 10 km MODIS 500 m  LANDSAT 30 m Irrigated area: 5199 ha Irriga...
<ul><li>Abandoned canals </li></ul>4. Understanding the differences Abandoned/changed cropland (canal system damaged but m...
5. GIAM China: the way forward
GIAM China: the way forward Issues to address in irrigated area mapping <ul><li>Definition of irrigation  </li></ul><ul><l...
<ul><li>Ground truth data collections </li></ul>Understanding the differences More GT points needed for extremely complica...
GIAM China: the way forward <ul><li>Ground truth data collections </li></ul><ul><li>Ground truth points </li></ul>Country ...
GIAM China: the way forward <ul><li>More accurate areas </li></ul><ul><li>More detailed crop types </li></ul><ul><li>Bette...
GIAM China: the way forward Finer resolution: 500m (MODIS) Source: IWMI, GIAM Project, 2006
GIAM China: the way forward Forests Rainfed-agriculture-millets Rangelands-grasslands Irrigated-conjunctive-cotton Plantat...
GIAM China: the way forward <ul><li>Provide irrigated area maps @ various scale/resolution </li></ul><ul><li>Provide stati...
GIAM China: the way forward GIAM main web portal Source: IWMI, GIAM Project, 2006
GIAM China: the way forward GIAM China Rain fed cropland  area mapping Wet land mapping Drought monitoring Water productiv...
Thank you www.iwmigiam.org
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Irrigated Areas of China based on Satellite Sensors and National Statistics: Issues and Way forward from Global Irrigated Area Mapping

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Irrigated Areas of China based on Satellite Sensors and National Statistics: Issues and Way forward from Global Irrigated Area Mapping - By Xueliang Cai, GIAM core team, International Water Management Institute (IWMI), May 23rd, 2007, Beijing

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Irrigated Areas of China based on Satellite Sensors and National Statistics: Issues and Way forward from Global Irrigated Area Mapping

  1. 1. Irrigated Areas of China based on Satellite Sensors and National Statistics: Issues and Way forward from Global Irrigated Area Mapping By Xueliang Cai, GIAM core team http://www.iwmigiam.org GIAM2007 China Workshop Global Irrigated Area Mapping with Focus on China (GIAM China) May 23rd, 2007, Beijing
  2. 2. <ul><li>The issues: </li></ul><ul><ul><li>Irrigated areas from remote sensing </li></ul></ul><ul><ul><li>Irrigated areas from national statistics </li></ul></ul><ul><ul><li>The comparison </li></ul></ul><ul><ul><li>Understanding the differences </li></ul></ul><ul><ul><li>The way forward </li></ul></ul><ul><li>主要内容: </li></ul><ul><ul><li>遥感灌溉面积提取 </li></ul></ul><ul><ul><li>统计灌溉面积 </li></ul></ul><ul><ul><li>两者比较 </li></ul></ul><ul><ul><li>差别原因分析 </li></ul></ul><ul><ul><li>下一步研究内容 </li></ul></ul>
  3. 3. 1. Irrigated areas from Remote Sensing
  4. 4. 1. Irrigated areas from Remote Sensing Global irrigated area map China irrigated area map TAAI* AIA* Rainfed area Total cropland area Watering method Irrigation type Crop type Scale intensity Spatial distribution * TAAI : Total Area Available for Irrigation, AIA : Annualized Irrigated Area Source: IWMI, 2006 Source: IWMI, 2006
  5. 5. 2. Irrigated areas from national statistics
  6. 6. 2. Irrigated areas from national statistics the Ministry of Land and Resources the Ministry of Water Resources the Ministry of Agriculture National land uses statistics National irrigation statistics National agricultural statistics Sources:
  7. 7. 2. Irrigated areas from national statistics <ul><li>Field measurements for all units </li></ul><ul><li>Summarized @ various administrative units (village => township => county => province => nation) </li></ul>Large scale field survey Down-top reporting <ul><li>Field measurement /estimation for changed areas </li></ul><ul><li>Reporting to upper administrative units (village => township => county => province => nation) </li></ul>Methods:
  8. 8. 2. Irrigated areas from national statistics Total crop land areas decrease Effective irrigated areas increase Source: Statistical Bulletin on China Land Resources, 2007
  9. 9. 3. GIAM China vs. national statistics: the comparison
  10. 10. 3.GIAM China vs. national statistics: the comparison Source: CHINA NATURAL RESOURCES DATABASE, CAS 129,205,000 N.A. N.A. 203,624,473 Total Cropland Area 75,805,000 N.A. N.A. 91,635,702 Total Rainfed Area 53,400,000 53,740,000 53,823,000 111,988,772 Total Area Available for Irrigation N.A. N.A. N.A. 151,802,086 Annualized Irrigated Area N.A. N.A. N.A. 7,688,411 Continuous Irrigated Area N.A. N.A. N.A. 68,233,355 Season2 Irrigated Area N.A. N.A. N.A. 75,880,320 Season1 Irrigated Area (ha) (ha) (ha) (ha) National statistics (1) FAO Aquastat FAO/UF (GMIAV3.0) GIAM 10 km Type
  11. 11. 3.GIAM China vs. national statistics: the comparison Source: CHINA NATURAL RESOURCES DATABASE, CAS
  12. 12. 4. GIAM China vs. national statistics: Understanding the differences
  13. 13. 4.1 Definition Issues 4. Understanding the differences
  14. 14. 4. Understanding the differences <ul><li>Irrigated area – the definition </li></ul><ul><ul><li>Irrigated area </li></ul></ul><ul><ul><ul><li>Low land (rice, lotus, etc. ) </li></ul></ul></ul><ul><ul><ul><li>Irrigated upland </li></ul></ul></ul><ul><ul><li>Effective irrigated area </li></ul></ul><ul><ul><li>Actual effective irrigated area </li></ul></ul><ul><ul><li>TAAI </li></ul></ul><ul><ul><li>AIA </li></ul></ul><ul><ul><li>Class naming </li></ul></ul>
  15. 15. 4.2 Limitation in National Statistics 4. Understanding the differences
  16. 16. <ul><li>Advantages: </li></ul><ul><li>Accurate </li></ul><ul><li>Detailed </li></ul><ul><li>Disadvantages: </li></ul><ul><li>Time consuming </li></ul><ul><li>Human sources consuming </li></ul><ul><li>Difficult to update </li></ul>4. Understanding the differences Large scale field survey Down-top reporting <ul><li>Advantages: </li></ul><ul><li>Easy </li></ul><ul><li>Low cost </li></ul><ul><li>updatable </li></ul><ul><li>Disadvantages: </li></ul><ul><li>Inaccurate </li></ul>Limitation of national statistics No spatial distribution information
  17. 17. <ul><li>Limitation of national statistics </li></ul>4. Understanding the differences <ul><li>Inconsistent area units mu (varies from 667 to 1500m 2 ) </li></ul><ul><li>Benefit driving factors (to evade taxes or water fees) </li></ul><ul><li>Area measurement/estimation errors </li></ul><ul><li>Compilation errors </li></ul><ul><li>Illegal land use change </li></ul><ul><li>… </li></ul>
  18. 18. <ul><li>Decrease of large irrigation system command area </li></ul>4. Understanding the differences Zhanghe Irrigation system, Hubei Existing irrigated area decrease in national statistics Source: IWMI project, 2005 New boundary Old boundary
  19. 19. Irrigated, small reservoirs , Rice, Single crop Irrigated, groundwater , rice, double crop Irrigated, small tanks , Rice, Single crop Areas in color are outside the CBIP irrigated area map…..what type of irrigation exist here?. 4. Understanding the differences Informal irrigation Source: IWMI, 2006
  20. 20. 4. Understanding the differences <ul><li>Informal irrigation missing in national statistics </li></ul><ul><li>Increase of small storages </li></ul>Limited development for large irrigation system, many local water storages are constructed in recent years Ponds construction years Source: IWMI 2005, More Rice with Less Water Size distribution of water bodies in 1978 and 2001 , ZIS, Hubei 100 Total 35 2000- 2003 35 1991-1999 30 1965-1990 Percent Year of construction
  21. 21. 4.3 Limitation in GIAM 4. Understanding the differences
  22. 22. 4. Understanding the differences local fractions Global fractions Global irrigated area fractions (IAF G ) are computed for large areas (e.g., sub-continent, world). Local irrigated area fraction (IAF L ) fractions are more relevant when computing areas for the local areas (e.g., state, district). Irrigated Area Fraction – IAF localization Source: IWMI, GIAM Project, 2006
  23. 23. <ul><li>Refinement of GIAM – Resolution effects </li></ul>MODIS 500 m Landsat 30 m AVHRR 10 km Syr Darya River Basin, Central Asia Finer the resolution greater the area 4. Understanding the differences Source: IWMI, GIAM Project, 2006 3,105,308 AVHRR 10km 3,459,126 MODIS 500 4,086,856 Landsat 30m Area ( ha) Satellite/Sensor
  24. 24. <ul><li>Refinement of GIAM – Resolution effects </li></ul>AVHRR 10 km MODIS 500 M LANDSAT 30 M Ruhuna river basin, Sri Lanka 4. Understanding the differences Source: IWMI, GIAM Project, 2006 0.12 GIAM 30 m 0.09 GIAM 500 m 0.079 GIAM 10 km Area in M ha Map at different scales
  25. 25. Misrepresentation of minimum mapping unit 10 km 10 km AVHRR 10 km MODIS 500 m LANDSAT 30 m Irrigated area: 5199 ha Irrigated area: 5822 ha Irrigated area:6559 ha 4. Understanding the differences Source: IWMI, GIAM project, 2006 Nagarjunasagar Command area Irrigated area Other LULC
  26. 26. <ul><li>Abandoned canals </li></ul>4. Understanding the differences Abandoned/changed cropland (canal system damaged but may still exists) Damaged canal Abandoned canal May still be interpreted as irrigated Photo Credit: IWMI, More Rice with Less Water, 2005
  27. 27. 5. GIAM China: the way forward
  28. 28. GIAM China: the way forward Issues to address in irrigated area mapping <ul><li>Definition of irrigation </li></ul><ul><li>Identify national statistics terms </li></ul><ul><li>Identify GIAM terms </li></ul><ul><li>Identify the gap and linkages </li></ul><ul><li>Other secondary data sources collection </li></ul><ul><li>Ground truth data collection </li></ul>
  29. 29. <ul><li>Ground truth data collections </li></ul>Understanding the differences More GT points needed for extremely complicated China irrigated areas Source: IWMI, GIAM Project, 2006
  30. 30. GIAM China: the way forward <ul><li>Ground truth data collections </li></ul><ul><li>Ground truth points </li></ul>Country boundary Total GT points:1132 Example: Ground Truth Data used in GIAM India 500m Source: : IWMI, GIAM project, 2006
  31. 31. GIAM China: the way forward <ul><li>More accurate areas </li></ul><ul><li>More detailed crop types </li></ul><ul><li>Better spatial distribution </li></ul><ul><li>… </li></ul>Multi-scales to finer resolutions GIAM 10km GIAM 500m GIAM 30m Map and establish Statistics at different Resolutions Source: IWMI, GIAM Project, 2006
  32. 32. GIAM China: the way forward Finer resolution: 500m (MODIS) Source: IWMI, GIAM Project, 2006
  33. 33. GIAM China: the way forward Forests Rainfed-agriculture-millets Rangelands-grasslands Irrigated-conjunctive-cotton Plantations with rice Fishponds-Aquaculture Finer resolution: 30m (LandSat ETM) Source: IWMI, GIAM Project, 2006
  34. 34. GIAM China: the way forward <ul><li>Provide irrigated area maps @ various scale/resolution </li></ul><ul><li>Provide statistics @ various administrative units </li></ul><ul><li>Operational system with online access to all users </li></ul><ul><li>Updated every 2~5 years (preferably) </li></ul><ul><li>Freely high quality data sources </li></ul><ul><li>…… </li></ul>Irrigated area mapping and reporting system for China (IAMRS China)
  35. 35. GIAM China: the way forward GIAM main web portal Source: IWMI, GIAM Project, 2006
  36. 36. GIAM China: the way forward GIAM China Rain fed cropland area mapping Wet land mapping Drought monitoring Water productivity mapping Institutions and policies
  37. 37. Thank you www.iwmigiam.org

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