Characteristics Of Soil And Water Loss In Typical Regions Of Hunan Province Based On CSLE

Soil and water loss is one of the more prominent ecological and environmental problems in Hunan Province.In response to the current status of soil and water loss,Hunan Province has launched a comprehensive monitoring task of soil and water loss.In this paper,four typical areas in Hunan Province are selected as the research objects:Tianlei Mountain-Xuefeng Mountain Provincial Key Soil and Water Loss Prevention Area in Southwest Hunan,Zhijiang Dong Autonomous County,Dongting Lake Plain Wetland Provincial Key Soil and Water Loss Prevention Area Yueyang County,Zishui Upper Province Level Shaodong County,a key soil erosion control area,and Changsha County,a general monitoring area for soil erosion.Using China's Soil Loss Equation(CSLE)as the main technical means to obtain the typical regional erosion factors in Hunan Province,to achieve the soil erosion calculation and intensity grading of the typical research area in 2019,and to analyze the characteristics of land use,slope and vegetation coverage and soil erosion It is hoped that through multi-angle research,it will provide direction and basis for the prevention and control of diversified soil erosion in Hunan Province.In 2019,the overall soil and water loss in typical regions of Hunan Province showed a controllable and stable trend.Except for a slight increase in local erosion intensity,the total erosion area in the four typical study areas has decreased from the 2018 data,and the overall situation is positive.good.The total area of soil erosion in the study area is 1105.11km2,accounting for 12.73%of the study area,of which,light erosion accounts for the largest proportion,with an area of 930.89 km2,accounting for 84.24%;moderate erosion 115.38km2,accounting for 10.44%;strong erosion 37.08 km2,accounting for 3.36%;extremely intense erosion 15.93km2,accounting for 1.44%;severe erosion 5.81km2,accounting for 0.52%.Characteristics of soil and water loss occurrence:(1)From the perspective of land use type:concentrated on forest land and cultivated land type,the area of erosion occurrence reaches 911.64km2,accounting for 82.49%;(2)from the perspective of terrain slope:concentrated on 8°?35° slope range The cumulative erosion area is 845.47km2,accounting for 76.50%;(3)From the perspective of vegetation coverage:concentrated in the range of 30%to 75%vegetation coverage,the erosion area is 897.33km2,accounting for 81.20%.Among the typical research areas in Hunan Province,Yueyang County has the worst soil erosion and Changsha County has the best.(1)From the erosion area of each study area:the soil erosion area of Yueyang County is 472.55km2,>315.57 km2 of Shaodong County,>205.73km2 of Zhijiang Dong Autonomous County,>111.26km2 of Changsha County;In comparison:Shaodong County 17.74%>Yueyang County 16.82%>Zhijiang County 9.82%>Changsha County 5.57%.The erosion in Yueyang County is characterized by a large total amount and a heavy degree,especially strong and above.The erosion area and the specific gravity are the highest,respectively 31.84 km2 and 6.74%.Due to hydraulic erosion in the lake area and watershed,soft soil,uneven spatial and temporal distribution of rainfall,rainfall splashing and large-scale surface runoff are important factors for increasing erosion;Shaodong County has the largest proportion of erosion in the region,and the erosion distribution is relatively balanced,with more intense and more erosion Distributed in the east.Due to the " Hengshao Arid Corridor”zone,the soil layer is thin,the water retention capacity is poor,the corrosion resistance is poor,the terrain and the water flow are obvious,and the surface runoff that is easy to form a large impact force increases erosion;the mountainous areas in the west of Zhijiang County and the hills in the east The erosion in the area is significantly differentiated,and the topography,vegetation and human factors are the main reasons for the boundary characteristics;Changsha County is characterized by a small area and a light degree The total erosion amount and the average erosion modulus are the lowest in the four counties,and the proportion of erosion levels above strong is very small,Soil and water conservation measures and management level are high.Therefore,the typical area of Hunan Province focuses on preventing and reducing large-scale mild erosion.For the governance of the lake area,Yueyang County expands vegetation coverage,reduces the total amount of erosion and alleviates the occurrence of severe erosion;Shaodong County surrounds the core area of the "Hengshao Arid Corridor".The key is to increase water resources and water conservation projects to reduce the area of erosion;The strong erosion caused by the densely populated areas in Jiang County has strengthened the management of water and soil conservation in production and construction and recovered after the destruction.The management of forest land and cultivated land should be two-pronged,and add targeted water and soil conservation measures,such as the establishment of dedicated forest land posts,slope protection and soil conservation projects,not only to expand the vegetation coverage area,but also to improve the vegetation coverage level and coverage quality,in order to effectively play the vegetation The effect of factors on the prevention and containment of soil erosion.