| The Loess Plateau with severe soil erosion is a typical area where complex erosion by wind and water occurs.The Jinghe River Basin is located in the hinterland of the Loess Plateau,and is one of the areas with the most serious soil erosion in the Yellow River Basin.In-depth study of the ecosystem soil conservation services and their supply-demand relationship in the basin is of great significance to promote ecological reconstruction,watershed comprehensive management and sustainable development.Taking the Jinghe River Basin as the study area,it is used the SWAT hydrological model and RWEQ wind erosion model of soil to simulate the ecosystem soil conservation services of hydraulic erosion and wind erosion in the Jinghe River Basin from 2000 to 2020 respectively,with measuring soil physical and chemical indicators through field sampling to improve the soil database of two models.Finally,the supply-demand relationship and profit&loss situation of soil conservation services was quantitatively analyzed.The main conclusions are as follows:(1)From 2000 to 2020,the soil conservation services of hydraulic erosion in the Jinghe River Basin have been significantly improved.The period of 2011-2020 was better than that of 2000-2010,and there was a strong correlation between the precipitation and hydraulic soil conservation.However,there were still some areas in the lower reaches of the basin that have not risen but fallen.(2)From 2000 to 2020,the total amount of soil conservation services for wind erosion in the Jinghe River Basin showed declining trend.Vegetation restoration and effective sand-fixing and wind-proof measures have weakened the wind erosion,giving rise to decrease in the soil potential amount of wind erosion in the basin ecosystem.(3)The soil conservation service function of the ecosystem in the Jinghe River Basin was significantly improved.However,due to the significant spatial and temporal differences between hydraulic erosion and wind erosion,the ecosystem soil conservation service had a fluctuating increase as a whole.Moreover,annual soil conservation services of hydraulic erosion were more than that of the wind erosion.(4)From the perspective of the supply and demand relationship of ecosystem soil conservation services,there was an overall surplus of soil conservation services in the Jinghe River Basin.It shows that the basin ecosystem can achieve a balance between supply and demand of soil conservation services,and has basically achieved "turning losses into profits".However,there are still some loss-making areas,where ecological restoration measures need to be strengthened.At the same time,it is in the areas with soil conservation services surplus that a long-term mechanism to protect and promote its ecosystem services should also be established. |
