Research On The Response Of Soil Erosion To Land Use Change Based On RS And GIS

Supported by RS and GIS technology,the paper takes Fengjie County,Chongqing City as the main research area,and Landsat TM(OLI)remote sensing images in 2000,2005,2010 and 2015 as the main data sources.According to the soil erosion equation RUSLE model,in order to quantitatively analyze the soil erosion pattern of the research area,the study takes regional meteorological,digital elevation,soil type distribution,population,socio-economic and other data into consideration,and by applying geodesic infographic models,the pattern of land use evolution in research area is analyzed.Together with the comprehensive analyzation of the coupling relationship between soil erosion and special topographic factors,the response mechanism of soil erosion and space-time evolution of land use types in this area is explored.The following conclusions are reached:(1)The overall regional structure of the research area is mainly consisted by forest land and cultivated land.Those two types together accounts for 94.57%,94.56%,93.93% and 94.97% of the total area in the four phases data respectively.Forest land with an area ratio of 66.76%,67.32%,67.37% and 93.75%,takes the most part.While arable land,grassland and unused land shows a decreasing trend of 2.86%,6.85% and20.56%,with the largest decrease in arable land at 78.84km2;Forest land,waters and residential industrial and mining land increase by 1.08%,127.11% and 34.34%,with the largest increase in the area of the waters at 46.67km2.The comprehensive dynamic degrees from 2000?2005,2005?2010 and 2010?2015 are 4.7%,4.7% and 0.05%respectively,which indicates that the rate of comprehensive change of the land type shifts from slow to very slow.(2)According to geodesic infographic model,the land transfer situation in the research area is analyzed.The conversion of land mainly occurred in forest land,grassland and cultivated land in both 2000?2005 and 2005?2010 phases,with cumulative change rate of the three land categories at 90.76% and 90.89%.Among all the changes forest land ? cultivated land claims the largest part in 2000?2005 as475.39km2;And for 2005?2010,cultivated land ? forest land,as 494.05 km2;In2010?2015,it was mainly converted among forest land,cultivated land and residential industrial and mining land,with a cumulative change ratio of 75.10% for the three land-use types.It also shows that urbanization rate,tertiary industry output value,fruit production,public budget expenditure and per capita disposable income of rural residents are highly positive indicators of changes in the area of industrial and mining land.(3)Micro-erosion and mild erosion are most commonly occurred in research area,with the total area ratios of 94.08%,97.27%,99.37% and 99.56% respectively.Mild erosion? micro-erosion transfer covers the largest area in 2000?2005(475.39km2),2005?2010(722.39km2)and 2010?2015(1112.87km2)phases,indicating that the overall erosion intensity is in a weaken trend and gradually concentrated towards micro-erosion.Soil erosion in the region can be found mainly in forest land and arable land,accounting for 94.88%,94.62%,93.85% and 93.67% of the total area of regional erosion.According to the proportion of area,mild erosion mainly occurs in forest land,with69.15%,68.90%,67.62% and 67.67%.Moderate and intense erosion in cultivated land,with an area ratio of 71.18%,87.48%,82.39% and 92.20%,respectively.(4)The influence of topographic factors on the spatial and ternary distribution of soil erosion in the study area is significant,and the type of soil erosion intensity is distributed much variously in different terrain zones.Erosion was most severe in slope zones with more than 15 degrees in the research area,where the area with intense and above degree accounts for 94.94%,93.93%,84.39% and 85.67% of the total area of severe erosion;The most severe erosion takes place in the 200m?500m and500m?800m elevation zones,where the area with intense and above degree accounts for59.62%,63.54%,59.57% and 70.68% out of the total.Soil erosion intensity,which occurs at different slopes and elevations,responds significantly to human activities.