The Relationship Between Landuse And Sediment In Loess Plateau China, Zuli River

The factors of sediment are affected by land-use changes., then the intensity and wise of sediment is caused to change. Unreasonable land use and decrease of vegetation cover may have amplified sediment yield in some extent. The terrain is changed. Soil is deteriorated and vegetation is destroyed. Finally, the sediment is increased. The land use change is the main cause of sediment. Land use readjustments and ecological restoration in Chinese Loess Plateau are the important stratagems for social and ecological development. Land use and precipitation variations in this have brought spatial and temporal changes in the factors of sediment.Based on 3S technology, this research focuses on Zuli River, a typical watershed in the Chinese Loess Plateau, to spatially model the spatial distribution of land use and sediment. First, using l:50,000DEM and multi-spectral radiometric data to obtain land use map of 1987, 1993, 2000, 2005. Second, overlaying the factors of sediment yield, such as slope, precipitation, soil, vegetation and land use type to obtain the spatial and temporal distribution of sediment. Finally, the relationship between land use and sediment has been discussed in this paper. The followings are the main of this dissertation:(1) DEMs can be used to factually simulate the surface information at scale of 1 : 50,000. The study result s can be used to guide the error rectification and the accuracy evaluation of DEMs in practical applications.(2) Using the precipitation data observed by the 36 weather stations (1956-2004) in Zuli River Basin. The spatial and temporal structure of precipitation in the Zuli River Basin was analyzed, by using Kriging method.(3) 1987-2005, the land use changes are: 1987-1993, grassland is decreased 2.88%, 2.83% of grassland is converted to farmland, and 0.05% is converted to residential areas. 1993-2000, grassland is decreased 0.25%, 0.19% of grassland is converted to farmland, and 0.06% is converted to residential areas. 2000-2005, farmland is decreased 2.96%, 2.94% of farmland is converted to grassland, and 0.02% is converted to residential areas. (4) The sediment is affected by the different land use types, and the irrational land use will accelerate soil erosion. So the rational land use ways and optimized land use structure are significantly important for regional sustainable development. 1987-2000, farmland has been increased and grassland has been decreased. The intensity of sediment in farmland and grassland has also been increased. 2000-2005, farmland has been decreased and grassland has been increased. The intensity of sediment in farmland and grassland has also been decreased, obviously in the grassland.To sum up, this research is validated the relationship between land use andintensity of sediment. It lays a foundation for future studies of reasonable land usestructure.