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Key Findings and Cross-Country Insights
Irrigation Water Shortfall Forecast in Three of Four Countries The water resources analyses conducted in each country on a basin level considered three projections: (1) change in water supply (runoff) from climate change; (2) change in water demand from all non-agricultural sectors (forecast based on projections of population and economic production); and (3) change in water demand from the irrigated agriculture sector for currently irrigated lands (an output of the crop modeling). Irrigation water demand will increase for most crop/AEZ/climate scenario combinations, owing largely to increases in temperature; but for several crops, particularly in Uzbekistan, in areas where precipitation is expected to increase, irrigation demand would decrease. In three of the four countries, however, the three projections (water supply, non-agriculture water demand, and agriculture sector water demand) combine to result in a forecast shortage of irrigation water, or “unmet irrigation demand.” The results indicate irrigation water shortages for at least one river basin in Uzbekistan, Moldova, and FYR Macedonia. Table 4.2 illustrates water shortages, or unmet demand, for both irrigation and municipal and industrial uses in one study country, Uzbekistan, on an annual basis. The monthly results for irrigation in Uzbekistan across all basins are shown in figure 4.4. Irrigation is so prevalent in Uzbekistan that the results show that future shortages are quite likely in multiple basins regardless of the climate scenario, and in most basins the future shortages under climate change scenarios are much worse than in the base, no-climate change case. For example, irrigation water shortages in the Amu Darya basin are 4–20 times larger
Figure 4.4 Average Monthly Irrigation Water Shortages over All Uzbekistan Basins, 2040s
Unmet water demand (cubic kilometers)
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Looking Beyond the Horizon • http://dx.doi.org/10.1596/978-0-8213-9768-8
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