Analysis On Temporal And Spatial Changes And Driving Forces Of Soil Erosion In Guizhou Province From 2000 To 2018

Guizhou is a typical area of karst landform in China,and is also one of the most serious provinces of soil and water loss.The ecological environment is fragile and the ecological status is important.The contradiction between the exploitation of resources under the influence of human and the deterioration of environmental damage makes soil erosion and vegetation degradation intensified.Therefore,tracing the trend of soil erosion and exploring the relationship between land use,vegetation cover(LUCC)and soil erosion are of great value for ecological restoration and soil and water conservation in the study area.Based on soil texture,topography,climate,land cover and land use data,using the revised universal soil loss equation(RUSLE)model,combined with GIS spatial analysis methods,this research studied the spatial distribution characteristics of soil erosion in urban areas and water systems and the dynamic changes of land use in Guizhou Province in 2000,2010 and 2018.And the impact of dynamic changes of land use on soil erosion intensity was quantitatively discussed.The main results are:(1)From 2000 to 2018,the main land-use types were cultivated land,forest land,and grassland.The transfer mainly occurred between cultivated land,forest land,and artificial land.(2)The main vegetation coverage grades from 2000 to 2018 are medium and medium-high vegetation coverage grades.The transfer of vegetation coverage mainly occurs in the range of 30%-75% vegetation coverage.The general trend is that the area with low vegetation coverage decreases and the area with high vegetation coverage increased.(3)From 2000 to 2018,the degree of soil erosion in Guizhou Province weakened,and the overall erosion grade changed from high to low.The area of slight erosion and mild erosion has increased,and the area of extremely strong erosion and severe erosion has decreased significantly.The soil erosion in nine cities and eight water systems decreased significantly.(4)Forest land is the main land use type to control soil erosion,grassland and forest land on soil erosion control is similar,the proportion of water area and urban and rural,industrial and mining,residential land in the low erosion level is increasing.In general,the characteristics of soil erosion change in the study area are: the increase of soil erosion grade is inversely proportional to the spatial and temporal changes of forest land,grassland and water area,and is proportional to the spatial and temporal changes of unused land and cultivated land.Urban and rural areas,industrial and mining,and residential land make the erosion grade change from both ends to the middle level.(5)Within 18 years,the proportion of low,medium and low,medium and high vegetation cover grades in areas with moderate erosion and below gradually increased,but the increase rate of coverage in medium,high and high vegetation cover grades was low.The soil erosion grade is directly proportional to the area of medium,low and medium vegetation coverage grade,and inversely proportional to the area of medium,high and high vegetation coverage grade.In general,the change of vegetation coverage has a higher impact on soil erosion than the changes of land use type.High vegetation coverage can significantly reduce soil erosion.