Application On Equitable Payment For Watershed Service (EPWS) Based On GIS And SWAT Model

Due to the aggravation of water and soil erosion, the benefits from the Xingfu II Hydropower Station was greatly impacted in Guanliao Watershed in Ebian County of Sichuan Province in China. In2011, the Xingfu II Hydropower Station, as a buyer, joined in the Equitable Payment for Watershed Service (EPWS) project which will a nice milestone for buyer and seller, in order to prevent the upstream water and soil erosion.The statements of sub-watersheds numbers, current water and soil erosion, and simulated runoff and sediments was determined, calibrated, validated and simulated in this study, based on the main technology of GIS(Geographic Information System) and SWAT (Soil and Water Assessment Tool) model. Also the directly economy benefits from downstream Xingfu Ⅱ Hydropower Station and local society benefits of upstream communities was analyzed and discussed. Main results are follows as:1. When the EPWS was conducted in the watershed of Xingfu II Hydropower Station, It will provide great benefits not only for the income upstream communities, but also for the reduced sediments in reservoir and increasing economy benefits for downstream Xingfu II Hydropower Station.2. EPWS can cause the ecological benefits and economy benefits for the win-win improvement on the communities and companies, through the operations from stakeholders groups in the watershed-level of the resolving local problems.3. The simulation of SWAT model was very complex not only the complex and great amounts parameters for different sub-watershed, but also the great deal works of simulation processes by inputing determined parameters, outputting calculation results, calibrating and validating relevant SWAT parameters and simulating SWAT models. Since the lack of measured technology, relevant background data and the limited data, it has a limitation of simulated results of runoff and sediments volume based on the simulation results from an only single watershed outlet at Xingfu II Hydropower Station by the parameters determination and model validation. More research contents will be carried out during EPWS in future.