Study on Land Use Change in the Water Supplying Core Area of Middle Route of South-To-North Water Transfer Project

Investigating the characteristics of dynamic changes of land use in the water source area of South-to-North Water Transfer Project (SNWTP) is of great significance to ameliorate the environmental quality to guarantee adequate, high quality water diverted into Beijing and Tianjin. The spatial and temporal characteristics of land use in the water source core area of middle route of South-to-North Water Transfer Project from 2009 to 2015 were analyzed by RS and GIS technologies based on national geoinformation survey data and basic surveying and mapping data, the results as follow: (1) the land was mainly covered with forest, which was accounting for about 80% of the total area. The area of cropland was reduced obviously, contrarily, the area of grassland increased prominently during the period from 2009 to 2015. The total coverage of wood and grass land rose lightly. (2) the land use transforming mainly occurred among cropland, woodland and grassland. Cropland was mainly changed to woodland and grassland, distributed in the altitude below 1000m and the slope above 15°. (3) the ecological engineering construction and reservoir resettlement policy had provided an effective backdrop for above changes. 53.47% of slope cropland was changed to woodland and grassland. However, there was still a considerable area of woodland, grassland transformation into slope cropland. The government should strengthen the protection of ecological environment, especially in the altitude bellow 1000m and the slope between 15° to 25°, in order to reduce the man-made environment destruction to the water supplying area.