Evaluation of Sustainable Environmental Flows Based on the Valuation of Ecosystem Services: a Case Study for the Baiyangdian Wetland, China

Using China's Baiyangdian Wetland as a case study, we evaluated the sustainable level of environmental flows for the wetland based on a statistical relationship between the ecosystem service values and hydrological data. We used canonical correlation analysis to reveal the relationships between seven major ecosystem services (gross production of agriculture, fish and reeds; water supply; recreation; culture; habitat protection; climate regulation; and water purification) and a hydrological dataset (annual inflows, annual outflows, mean annual water elevation, 7-day low elevation, duration of the flood pulse, and number of days of extreme drought) from 1980 to 2005. Using this approach, we established a gray relationship matrix to reveal the influence of the hydrological parameters on the ecosystem services value. Using the hydrological parameters shown to significantly influence the ecosystem services values as the set of environmental flows, we evaluated the sustainable environmental flows by mean of cubic spline interpolation between data points to identify the maximum wetland ecosystem services value. The results were justified by referring to the natural hydrological regime in the 1960s and 1970s. Based on the results of this comparison, our approach provides an effective way for managers to regulate the flows of water to satisfy the wetland’s environmental flow requirements while also obtaining the maximum socioeconomic benefit.