1. Xueliang Cai, Bharat Sharma International Water Management Institute Agricultural Water consumption in the Limpopo and the Indo-Gangetic Basins – A Quick Comparison

2. Is the comparison meaningful? Yes, it is Basin perspective, powered by remote sensing, helps… … and vast differences in social and economic situations…

3. Methodology Evapotranspiration – key agricultural water consumption Actual ET map potential ET map ET a – actual Evapotranspiration , mm. E T f – evaporative fraction , unitless. ET 0 – Potential ET, mm. T x – Land Surface Temperature (LST) of pixel x from thermal data. T H /T C – the LST of hottest/coldest pixels . SSEB ET fraction map MODIS LST Daily weather station data Crop dominance map

4. ET maps Actual ET map of the Limpopo for the year 2005 Actual ET map of cropland areas in the IGB for the year 2005-06 Unit: mm Limpopo IGB Average Min Max SDV Limpopo 779 88 1814 208 IGB 944 145 1629 222

5. Factors affecting water consumption ETa / rainfall Crop water stress (ET a /ET p ) Higher ET at downstream areas and South African commercial irrigated areas Higher ET in Indian Punjab and Haryana and downstream areas Limpopo IGB

6. Factors affecting water consumption ET a / rainfall Limpopo IGB As opposed to the Limpopo basin, the IGB with extensive irrigation clearly showed the areas where ET exceeds precipitation and where not.

7. Factors affecting water consumption - IGB

8. Factors affecting water consumption - Limpopo The temporal evolution of rainfall against ET at selected sites in the Limpopo basin

9. Improving water management to improve agricultural water productivity IGB: targeting at bright spots? Is there enough water? Sustainability? Limpopo: how to improve yields? Regulate water consumption at the right timing?

10. Thank you!