Driving Mechanism Analysis And Stability Evaluation Of Soil Erosion In Loess Hilly And Gully Region Of Northern Shaanxi Province

The agricultural production in the Loess Plateau is mainly based on grain production.However,due to the constraints of natural environmental conditions in this region,the poor soil and sparse surface vegetation cover the soil and its constituent materials.At the same time,with the increasing population and unbroken farmland,the vegetation coverage and the soil stability decreases,and the grain production space continues to shrink.In turn,the formation of soil fertility decline → grain yield decline → expansion of planting area → deforestation and land reclamation → soil erosion → soil fertility decline,and eventually regional soil erosion is intensified,and ecological environment continues to deteriorate.The loess hilly and gully region of northern Shaanxi is located in the hinterland of the Loess Plateau and runs across the main stream of the Yellow River.It is the main part of the Loess Plateau in northern Shaanxi.The total area of the region is about 32,500 square kilometers,accounting for 15.8% of the land area of Shaanxi Province.The terrain in the area is broken,and the gully is vertical and horizontal,which is one of the most serious areas of soil erosion in the middle reaches of the Yellow River.In addition,due to the excessive population growth caused by deforestation and land reclamation,soil erosion is intensified,and the ecological environment is deteriorating,resulting in a fragile ecological environment in the region and a vicious cycle of the ecological economics,which has long been in a state of poverty and backwardness.At the same time,the loess hilly and gully region of northern Shaanxi is the key area of “granary construction” in Shaanxi Province.In recent years,large-scale land remediation projects have been implemented.Therefore,it is urgent to evaluate the soil stability in the implementation area of the land remediation project.Through combing the research results of soil erosion in the existing Loess Plateau,it is found that the existing research focuses on the simulation and analysis of soil erosion mechanism and process,and the influence mechanism of the influence factors affecting soil erosion.There are a few related studies.The existing measures for soil erosion are more based on the soil erosion equation,and the factors affecting soil erosion in different regions may be neglected.Based on the existing research results of soil erosion,using soil erosion degree as the main measure of soil stability,using the principal component analysis and geographic detectors to establish a soil stability evaluation index system,and using GIS spatial analysis method are fast and effective The ground assessment of the factors affecting soil stability is scored and plotted.By constructing the evaluation system and using GIS spatial analysis,the soil stability of the loess hilly and gully region in northern Shaanxi was evaluated,and the thematic map of soil stability evaluation was formed.The research results can provide a reference for the study of soil and water conservation research and related projects in the study area,provide a theoretical basis for the demonstration and implementation of land remediation projects,and provide the basis for key monitoring and prevention of geological disasters such as landslides and debris flows in the region.Based on the results of geo-detectors and principal component analysis,the spatial differentiation of soil erosion and its driving mechanism in loess hilly and gully regions of northern Shaanxi were studied.The influence factors of soil erosion factors were analyzed,and the interaction mechanism between the influencing factors was analyzed.The statistically significant driving factors of soil erosion were determined.The influences of population,land use type and GDP on soil erosion over time were also studied.The factors driving the soil over time were summarized.The law of change in the influence of erosion.The main conclusions are as follows:1.The degree of soil erosion in the loess hilly and gully region of northern Shaanxi is mainly hydraulic erosion,and there are obvious spatial differences.The analysis of soil erosion status shows that the soil erosion in the loess hilly and gully region of northern Shaanxi is mainly hydraulic erosion.According to the industry standard of the People’s Republic of China(Soil Erosion Classification Classification Standard SL190-96),the degree of erosion is divided into six levels,followed by micro-degree.Mild,moderate,strong,extremely strong and intense.Soil erosion has significant spatial differences,with less soil erosion in the south,severe soil erosion in the northern region,and strong soil erosion in the central and western regions.2.The increase in vegetation coverage and the increase in urbanisation have a significant impact on soil erosion changes.Based on the changes in land use area of the land use data statistics study area,the proportion of forest land and grassland area showed an increasing trend year by year,indicating that the proportion of ecological land areas such as forest and grassland was negatively correlated with the severity of soil erosion,forest land and grassland.The increase in the proportion of ecological land such as waters will help to improve the soil erosion resistance of the region.At the same time,it is found that although the population and GDP in the study area continue to grow,the population distribution and economic output are increasingly concentrated in space due to the advancement of urbanization,which makes it also have a significant positive effect on regional ecological,environmental protection and sustainable development.3.The soil stability in the loess hilly and gully region of northern Shaanxi is generally low and there is a significant difference in space.The soil stability in the loess hilly and gully region of northern Shaanxi is generally low,and the soil erosion resistance is weak.The low vegetation coverage area is likely to cause severe soil erosion under heavy precipitation and may cause geological disasters such as landslides and mudslides.At the same time,the evaluation results show that there are obvious spatial differences in soil stability in the region,forming unstable regions in the Jiaxian,Jude and Yanchuan areas in the east,and relatively stable areas in the central part of Zizhou and Ansai,Wuqi and Pagoda.The western and southern stable areas dominate the area.Through analysis,it is found that the spatial distribution of topographic factors in the study area is relatively uniform,and there is no obvious spatial difference,while the precipitation data and land use data show strong spatial differentiation,and the regional differences are significant;the results of soil stability evaluation are compared.There is a great similarity between spatial distribution patterns and spatial distribution patterns of precipitation data and land use data.