Abstract:
Taking the soil conservation service of the Jinghe River Basin in the Loess Plateau as an example, the annual sediment yield of the Jinghe River Basin from 2003 to 2018 is simulated based on the SWAT model, and the soil conservation service is divided into three parts: reducing sediment deposition, protecting soil fertility, and reducing land waste. The profit and loss status of soil conservation services in the sub-watershed is analyzed.Taking the service of reducing sediment deposition as an example, the spatial flow path is described and the flow is calculated in the scale of slope,channel and sub-watershed.The results show that:in terms of inter-annual variation, the services of reducing sediment deposition, protecting soil fertility, and reducing land abandonment show a fluctuating and increasing trend.In terms of spatial distribution, the area with flat terrain and good vegetation coverage has larger service volume.The profit and loss of soil conservation service in each sub-watershed are obviously constrained by the terrain. The areas with flat terrain are in surplus in most years, whereas the areas with complex terrain are in deficit in most years. The sediment mitigation service in soil conservation service belongs to the directional service flow, which depends on the natural transmission of "soil erosion-transport-deposition" path, and the flow has cumulative benefits with the increase of distance.
