Assessment on soil conservation service based on InVEST model —a case study of Yindingge mining area

Based on the SDR module of the InVEST model, the soil conservation function before and after ecological restoration in the small watershed of Yindingge mining area, Datian County, Fujian Province was evaluated and analyzed with the rainfall erosivity, soil erodibility, vegetation coverage, DEM and soil conservation factors. The results showed that the total area and intensity of soil conservation in the study area increased significantly after ecological restoration, and the intensely/more intensely eroded-area decreased from 21.0% to 8.7%, indicating a good effect on soil conservation improved by the ecological restoration project. The soil conservation intensity of paddy field and forestland was stronger. The vegetation coverage expanded with the rise of slope gradient, while sediment retention capacity and soil conservation capacity were also enhanced correspondingly. The design of SDR module considers the block's ability to intercept upstream sediment, making the calculation result of soil conservation function more actual, accurate and intuitive.