Economic Benefits of Controlling Water Pollution in an Irrigated River Basin: Methodology and Application

摘要

An analytical model consisting of a water quality submodel and an economic submodel was developed. The water quality submodel consisted of three elements: parameters, water quality index functions, and an aggregation rule. The parameters defined water quality as a multidimensional vector, with each component representing some aspect of the physical, chemical, biological, and aesthetic characteristics of water affecting water uses. The water quality index functions translated the measured levels of parameters into numerical values of quality levels which water users could interpret. Basically, this submodel provided estimates of aggregate net social benefits to be derived from water quality changes. The model was tested and demonstrated by application to three typical water quality improvement policies: stream flow augmentation, reduced sediment levels, and reduced nitrate levels. These findings imply that water quality standards may be too high, and achieving these standards may not be economically efficient.