Evaluation Of Soil Erosion Patterns And Risk In Typical Watershed Of Southern Red Soil Region

Soil erosion,called "the peristaltic disaster",is one of the most common and strongest persistent gradual natural disasters faced by human beings.Multiple types of erosion coexist,barren soil,economic rapidly growth and large population density,which are increasing demand of agricultural production and land development.The risk of soil erosion is higher than that of Loess Plateau.Research on spatial pattern of watershed soil erosion and risk evaluation of red soil region to construct the safety control and risk management system,the soil erosion of watershed management and risk reduction is of great significance.Taking Changting county's Zhuxi river watershed of Fujian province's red soil region as a example,through 3S technology,field observation and investigation,indoor experiment,PRA household survey and statistics analysis,which can calculate soil erosion modulus,and analysis basin soil erosion pattern and evolution,building landscape erosion ecological risk by suitable particle size and the index of basin soil erosion and risk vulnerability from the perspective of farmers' soil erosion awarenes and risk management.The main results are as follows:(1)Based on the revised universal soil erosion equation(RUSLE),calculating the soil erosion intensity of Zhuxi river watershed and analyzing the relationship between erosion evolution and related factors.The overall trend of soil erosion ratio and soil erosion intensity index is decreasing,but it is lower in the eastern and western,and higher in the middle of the Zhuxi river watershed.(2)Based on Fragstats4.2 calculating soil erosion landscape pattern.With the change of grain,the changing landscape pattern index of grain erosion appears to be irregular,subdued and enhanced,landscape pattern index analysis' best particle size is 20m,and calculate landscape's ecological risk of Zhuxi river watershed.The risk of landscape ecology is large in the middle area,and small in the eastern and western,the ecological risk of erosion is gradually reducing.(3)Selecting the evaluation indicators of hazard and vulnerability,using the method of combination weighting methods to determine the indexes of the weight.Soil erosion risk assessment model was used to determine the risk status and evolution of soil erosion in Zhuxi river watershed.The overall trend of soil erosion risk is decreasing,and it is lower in the eastern and western,and higher in the middle of the Zhuxi river watershed.Simulating human activities' contribution value on soil erosion risk,human activities make the risk of reduction is higher than the natural factors,and human activity is one of the important factors of soil erosion risk.(4)Based on participatory rural appraisal(PRA)to perceive soil erosion and erosion risk.On the basis of farmer risk perception,combining with the landscape's ecological risk and soil erosion risk,considering the impact of climate change on soil erosion risk,using biological measures,engineering measures and cultivation measures to control soil erosion and manage soil erosion risk of Zhuxi river watershed and Speed up social and economic development of the watershed,increase farmers consciousness on disaster prevention and mitigation,and reduce the risk of soil erosion.The study provides some ideas and reference value for soil erosion control,erosion risk control and soil erosion control in southern red soil region.