1. Xueliang Cai, Wim Bastiaanssen
Remote sensing based crop water productivity for investment in and management of mega irrigation systems in Asia
Xueliang Cai, Wim Bastiaanssen

2. Background
Water productivity concept is widely accepted and the remote sensing approach produces beautiful maps.
…So what?
How water productivity can be operationalized to help make better investment and management decisions?

3. Background
Asian Development Bank (ADB) is working with many countries to invest hundred of millions USD in irrigation;
But how should the irrigation performance be measured? And how this measurement can lead to improved investments and management?

4. Performance indicator
Our method
pySEBAL: a crop water productivity tool to convert satellite images to water use, soil moisture, crop growth, and water productivity
Remote sensing
(Crop biomass, leaf area index, nitrogen, yield)
Crop water productivity
(ETa, ET deficit, Evaporation, Transpiration, soil moisture)
Diagnostic analysis
Performance indicator

5. India, Rice Water productivity maps for performance assessment
Good CWP (average 1.47 kg/m3)
Moderate variability (CV = 0.14)

6. Factors affecting water use, yield, and WP
Distance to the main dam

7. Factors affecting water use, yield, and WP
Soil type

8. Factors affecting water use, yield, and WP
Crop calendar and intensity

9. Factors affecting water use, yield, and WP
Fertilizer (type and rate)

10. Factors affecting water use, yield, and WP
Seed

11. Establishing the investment target
Assessing potential
BC = Ta / ETa
Big and uneven potential for on-farm water management improvement

12. Establishing the investment target
Determining priority

13. Remote sensing works better with ground information
Final remarks
Crop water productivity needs to move beyond being research and policy concept
Operationalization of CWP requires looking at the elements contributing to CWP (crop, water, and biophysical and managerial factors)
Remote sensing approach is mostly used for monitoring and performance assessment, but it can also be a powerful diagnostic tool for planning and management
Remote sensing works better with ground information

14. Dank ye!