Study On The Effect Of Watershed Land Use Change On Runoff

Land-use and land-cover change have a significant impact on the form of water resources as well as space-time configuration, unreasonable land-use will result in changes on land-use and land-cover in the basin scale, which affected the flood processes to a certain extent. Runoff change is a sensitive factor of hydrological cycle, therefore, the research about the impact of LUCC on runoff yield is of great meaning for water resources planning, management and sustainable development. In recent years, as a result of the water resources utilization and human activities, the land use and land cover in Haihe basin change a lot, which results in the runoff and flood volume decrease. So it is necessary to compare and analyze runoff change under different land use.1. In this article, Zijingguan basin of Daqing river system was selected. The physically-based distributed SWAT model was applied to the runoff simulation of this basin. With the support of Geography Information System, DEM and the soil classification image were obtained, the remote sensing and GIS help us to get the land use data of 1980's and 1990's, to unify all the projection and coordinate parameters of the GIS data to get the thematic maps.2. 21 sub-watersheds have been delineated from the DEM by using the watershed automatic delineation tool in the avswat extentions of the ArcView. The land use data in the 1990's was input into the model, and runoff data of Zijingguan station from 1984~1996 were used to calibrate and validate the model parameters. The simulation results are satisfactory, and the results show that SWAT model could be successfully used to simulate the runoff in this area.3. Comparing the land-cover status in 1980's and 1990's,the areas of the woodlands are decreasing. But the areas of the arable land, the grassland and the construction land are all expanding. This paper adopted two land-cover status in 1980's and 1990's and simulated the runoff from 1984~1996. compared with the results simulated by the two landuse status, it is shown that the runoff is influenced by the changes of the land-use, and the general trend of runoff is decreased. Runoff in May,June,July reduced much more than other months.