Ecological degradation of an inland river basin and an evaluation of the spatial and distance effect on willingness to pay for its improvement.

Improvements in the ecological attributes of inland rivers have been projected to provide considerable non-market benefits, and the monetary valuation of these attributes has steadily increased over the past several decades. The present study addresses the spatial heterogeneity of the public's preference for ecological attributes and the distance-decay effect of willingness to pay (WTP) to improve various attributes of the river basin. The results revealed that spatial heterogeneity exists among the individuals; for example, the respondents of Liangzhou County prefer a large improvement in the natural landscape, forest coverage, and eco-tourism and are willing to pay 491.89, 369.32, and 338.37 yuan per year, respectively, for one unit improvement in these ecological attributes. Similarly, the respondents of Jinchang County value and are willing to pay 447.60, 431.81, and 318.18 yuan for one unit improvement in tourism, forest coverage, and natural landscape, respectively. Furthermore, the results from the random parameter logit model show a significant distance-decay effect of the household WTP for ecological attributes. For example, the respondents living within 5 km of the river are willing to pay more money, that is, 832.61, 365.62, and 353.05 yuan per year for improving the natural landscape, water quantity, and grass cover, respectively. As the distance from the river increases, the corresponding WTP decreases, meaning that the respondents (users) living near the Shiyang River Basin are willing to pay more for ecological attribute improvement than those living far away from the river.