Water scarcity and the impact of improved irrigation management: a computable general equilibrium analysis
基于GTAP-W模型，分析了全球范围内提高灌溉效率对节水和福利的影响，发现对缺水地区福利多为正面，对非缺水地区效果不一。
Increasing water scarcity combined with an increasing demand for food and water for irrigation call for a careful revision of water use in agriculture. Currently, less than 60% of all the water used for irrigation is effectively used by crops. Based on the new version of the GTAP-W model we analyze the effect of potential water savings and the welfare implications of improvements in irrigation efficiency worldwide. The results show that a water policy directed to improve irrigation efficiency led to global and regional water savings, but it is not beneficial for all regions. The final effect on regional welfare will depend on the interaction of several different causes. For instance, higher irrigation efficiency changes opportunity costs and reverses comparative advantages, modifying regional trade patterns and welfare. For water-stressed regions the effects on welfare are mostly positive. For nonwater scarce regions the results are more mixed and mostly negative. The results show that exports of virtual water are not exclusive of water abundant regions.