Variation of economic value produced by environmental flow in water-scarce basins of Northwest China

With intensification of human activities, environmental flow is often diverted for human use, particularly in areas with water scarcity. Accurate assessment of economic value produced by environmental flow will help protect environmental flow by means of economics. Based on the concept of opportunity cost, we can estimate economic value produced by environmental flow in water-scarce basins by the maximum loss caused by reduced amounts of water and the availability of water for other purposes. In this study, we propose a method that combined results of water scarcity assessment incorporating environmental flow with an opportunity cost approach to obtain economic value produced by environmental flow on the sub-basin scale. Then, we take the Wei River Basin in Northwest China as an example to test the feasibility of this method and use scenario analysis to discuss the influence of climate factor and land-use factor on economic value produced by environmental flow. This method can better present distribution and variation characteristics of economic value produced by environmental flow more directly and provide a reference for future ecological compensation in water-scarce basins. HIGHLIGHTS Economic value produced by environmental flow was a novel direction for recent environmental flow research.; A simple approach was proposed in this study to present the considerable economic value produced by environmental flow in monetary terms.; Economic value produced by environmental flow was displayed in the form of maps that more directly reflected distribution and variation of economic value produced by environmental flow.; The influence of climate factor and land-use factor on economic value produced by environmental flow was discussed by means of scenario analysis.; The Wei River Basin, which is the typical water-scarce basin in Northwest China, was taken as a case to test the feasibility of this method.