Research On Soil Erosion Driven By Land Use Change Based On GIS And R

This paper takes Fangzheng County,Harbin City as the research area,and uses Landsat TM and OLI remote sensing image data from 2005,2010,2015,and 2020 as the main data source.Using GIS and RS technology,it quantitatively extracts regional land use change data,and uses principal component analysis to analyze land use change and its driving forces;Based on this,combined with regional rainfall,terrain,soil,and other data,using the RUSLE model,determine the value of various factors in the study area,and quantitatively analyze the spatial change characteristics of soil erosion in Fangzheng County from 2005 to 2020;Then,the characteristics of regional soil erosion driven by land use change are discussed from the perspectives of land use types and topographic factors such as altitude,aspect,and slope.The results are as follows:(1)From 2005 to 2020,the range of land use change in Fangzheng county is obvious.The land use types are mainly forest land and cultivated land.The sum of the four phases accounts for 89.50%,89.94%,89.92%and 87.28%of the total area of the study area respectively.Among them,the forest land occupies the widest area,accounting for 66.58%,65.33%,65.31%and 65.05%respectively.On the whole,the cultivated land and water area showed a decreasing trend,and the change area of forest land was small;Grassland,unused land and construction land showed an increasing trend.(2)From 2005 to 2010,the transfer of land use types was concentrated between forest land,cultivated land and grassland,with an area of 410.53km~2;From 2010 to2015,the transfer was concentrated between forest land,cultivated land and construction land,with a transfer area of 18.54 km~2;From 2015 to 2020,the conversion between forest land,cultivated land,unused land and grassland will be further expanded,with a transfer area of 847.70km~2.Based on principal component analysis,the main driving factors affecting the change of land use pattern in Fangzheng county are urbanization rate,primary industry,tertiary industry,total output value of agriculture,forestry,animal husbandry and fishery,social fixed asset investment,etc.(3)In the past 15 years,micro erosion and moderate erosion have the widest distribution,and the total area accounts for 93.97%,96.62%,98.43%and 99.25%of the total area respectively.The soil erosion in the study area has been continuously improved,and the micro erosion shows a continuous growth trend,with an increase area of 461.74 km~2;Mild,moderate,intense,extremely intense and severe erosion all showed a decreasing trend,reducing 311.66km~2,123.11km~2,22.79km~2,6.52km~2and3.14km~2respectively.The area of soil erosion intensity transfer is mainly mild and slight erosion,and the weakened area is greater than the enhanced area.(4)Soil erosion in Fangzheng county mainly occurs in forest land and cultivated land,and the sum of the two erosion areas accounts for 89.50%,89.94%,89.92%and87.28%of the total soil erosion area respectively.The micro erosion of cultivated land,forest land,grassland and unused land shows an increasing trend,increasing by164.11km~2,251.87km~2,25.15km~2and 124.38km~2respectively;The erosion intensity of cultivated land,forest land and grassland decreased by 182.32 km~2,292.4 km~2and5.17 km~2respectively.(5)Among the characteristic topographic factors affecting soil erosion,soil erosion mainly occurs in the elevation zone of 0-300m and 300-600m,sunny slope,semi sunny slope,shady slope and semi shady slope direction zone,and 0°-15°slope zone;Soil erosion is more serious in the elevation zone of 1200-1500m,the slope direction zone of semi sunny slope and semi shady slope,and the slope zone of25°-35°.