The Research Of The Impacts Of The The Grain For Green Project On Soil Erosion In Shaanxi Province

Soil erosion is a global problem that leads to land degradation and damage to ecosystem services.Only from 2001 to 2012,the total amount of soil erosion caused by land use changes in the world increased by 2.5%.China’s soil erosion problem has a long history,especially in the Loess Plateau.Since the last century,the ecological problems caused by soil erosion have been very serious.Therefore,in the 1990s,China proposed the Grain for Green project to specifically respond to the problem of soil erosion.The project has achieved remarkable ecological results in the past 20years,and the regional soil erosion is also under effective control.While soil erosion,as one of the important indicators of ecosystem services,is the result of the interaction between natural factors and human factors,so it’s significant to assess the impact of the Grain for Green project on soil erosion under the interaction of natural factors and socio-economic factors for the sustainable development of regional ecosystems and the construction of ecological civilization.This study combed the domestic and foreign literature on the Grain for Green project and soil erosion,combined with the corresponding theoretical basis,subdivided the research perspectives and entry points.Taking 107 counties and districts in Shaanxi Province as examples,first this study analyzed the temporal and spatial characteristics of regional land use changes during the implementation of the Grain for Green project,and then it quantitatively assessed the soil erosion in Shaanxi Province from 2000 to 2015 using the revised Universal Soil Loss Equation(RUSLE).After obtaining soil erosion data at the county level,combined with the investment amount data of the Grain for Green project,the socio-economic factors included in the measurement empirical,this study explored the impacts of geographic characteristics such as rainfall,slope,and sunshine duration on the prevention and control of soil erosion by the Grain for Green project using the fixed-effect model of panel data.Finally,the geographically weighted regression model is used to explore the spatial heterogeneity of the impacts of the project on preventing soil erosion.The results showed that:(1)During the study period,the change of regional land use was mainly from cultivated land to forest land and grassland,and the area of regional forest land and grassland increased significantly driven by the Grain for Green project.(2)From 2000 to 2015,the level of soil erosion in Shaanxi Province decreased significantly and the total amount of soil erosion decreased from341.66×10~6t in 2000 to 282.61×10~6t in 2015.Besides,there was obvious heterogeneity in regional soil erosion intensity and its spatio-temporal variation characteristics.For example,the soil erosion intensity in Northern Shaanxi region was the highest meanwhile the decline was also the most precipitous,while Guanzhong region and Southern Shaanxi region were not.(3)The Grain for Green project had a significant positive impact on the prevention and control of soil erosion.It showed that for every 10000 yuan increased in investment,the amount of soil erosion decreased by 26.30t.At the same time,compared with Guanzhong region and Southern Shaanxi region,the effect of soil erosion control in Northern Shaanxi was more significant.(4)Geographical characteristics had a significant moderating effect on the effect of the Grain for Green project on soil erosion control.Slope and rainfall had a significant negative effect on the soil erosion control effect of the project,while the sunshine duration showed a positive moderating effect.(5)The investment of the Grain for Green project had obvious spatial heterogeneity in the effect of soil erosion prevention and control.The cost effectiveness of investment in northern Shaanxi is the highest,and that in southern Shaanxi is the lowest.The above research provide scientific practical basis and theoretical support for the sustainable implementation and the effective investment of funds of the new round of ecological restoration projects.