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

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

3. 1. Irrigated areas from Remote Sensing

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. 2. Irrigated areas from national statistics

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:

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. 3. GIAM China vs. national statistics: the comparison

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. 3.GIAM China vs. national statistics: the comparison Source: CHINA NATURAL RESOURCES DATABASE, CAS

12. 4. GIAM China vs. national statistics: Understanding the differences

13. 4.1 Definition Issues 4. Understanding the differences

15. 4.2 Limitation in National Statistics 4. Understanding the differences

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

21. 4.3 Limitation in GIAM 4. Understanding the differences

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

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

27. 5. GIAM China: the way forward

32. GIAM China: the way forward Finer resolution: 500m (MODIS) Source: IWMI, GIAM Project, 2006

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

35. GIAM China: the way forward GIAM main web portal Source: IWMI, GIAM Project, 2006

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. Thank you www.iwmigiam.org