Spatio-temporal Dynamic Analysis Driven By Land Use/Cover Change On Soil Erosion

Soil erosion of the Loess plateau is a serious environment problems,the quantitative evaluation of river basin soil erosion,besides it is a importment research proposition of sediment yield,discipline of soil and water conservation science,remote sensing and geographic information science.In this paper,based on the principles of soil erosion,soil erosion model combined with remote sensing and GIS technology,with 5 for nearly 40 years of land use and vegetation coverage information(1975、1986、1997、2006 and 2013)and empirical based on the distributed watershed erosion and sediment yield model.Analyzed the land use and land cover change and the temporal variation of soil erosion and the relationship between these.For two watershed provide data and technology support of soil and water conservation. The main research result as follows:(1)The watershed sediment yield model based on hillsolp erosion combined with GIS was applicable soil erosion quantitative and spatial-temporal dynamic analysis of Loess hills I deputy district and loess hill II deputy district.(2)The cultivated areas increase every year while grassland areas and vegetation cover fraction gradually decreasing from 1975 to 1997, After 1997t, The Cultivated areas slowly reduced,grassland and woodland areas gradually inceased and vegetation cover fraction significantly increased.(3)During the study period, the overall trend is decrease of soil erosion, the soil erosion modulus mean of Gushanchuan increased 3168 t/km2-a in 1997 from 1975 of 2658 t/km2-a than decrease to 2013of 1728 t/km2-a and main erosion were slight degree degree and moderate degree erosion,the soil erosion modulus mean of Yanhe increased 7946 t/km2-a in 1997 from 1975 of 4513 t/km2-a than decrease to 2013 of 5511 t/km2-a and main erosion were moderate degree.Besides erosion type conversions of basins mainly among neighboring erosion intensity level.(4)Research on the relationship between land use, vegetation cover and soil erosion show that cultivated land was moderate degree erosion, sandy erosion is more serious.Soil erosion intensity increased with increasing of cultivated land and sandy,decreasing of grassland.The cultivated land are moderate degree and intensive erosion,grassland and woodlang are slight degree and moderate degree erosion of Yanhe basin. Similar with Gushanchuan basin,Increased cultivated land is predisposing factor of erosion aggravating while increased woodland and grassland is control factor of erosion weaking.Therefore,reasonable land use is effective means of preventing and cotrolling soil erosion.