The Effect Of Landscape Change On Surface Runoff Of Jinxiuchuan Watershed Of South Mountain In Jinan

Jinan is famous for"springcity",The southern mountain region supplements groundwater to the springs of Jinan City, and its unique geological structure offers predominant natural conditions for forming springs and the circulation of the groundwater of Jinan City. The region plays an irreplaceable role in supplementing land groundwater to the springs and improving the environmental quality of the whole city and protecting the security of drinking-water in the urban. But because of the no-coordination of urban landscape element and bad landscape pattern. It greatly aggravates the function of the urban landscape. The research of landscape change and eco-hydrological effect has the significant theory and the practice meaning.Based on the successful experiences home and abroad and the hydro-ecology theory, integrating with RS and GIS technique, this paper chooses the advanced and perfect watershed management model- Soil and Water Assessment Tool(SWAT) model to study on the 5-year long numerical simulation of hydrology in the Jinxiuchuan watershed of southern mountainous areas in Jinan. Using the technique of GIS, the paper analyses the climate, hydrology, soil and land uses in the study area. Combined with the actual data and by applying the SWAT model, this paper also simulates and analyses the runoff in the watershed. The study shows that the SWAT model can be used to simulate the water product considerably in the Jinxiuchuan watershed.The conclusions are as follows:1) Build spatial database of the study areaBased on the field exploration and the collated data, the paper builds the spatial database of the region of interest, Spatial database of the region of interest including DEM , land use map and soil map, using the RS and GIS technique.2) Build the attribute database of the study area.Attribute database of the region of interest mainly include those of land use, physical attribute database and chemical attribute database of soil, parameters of cover with the vegetations, weather data, and so on.3) Simulate the runoff and analyses the result of the region of interestThe paper analyzes the precipitation data and the runoff data between the measured and the simulated, and then sums up the rules for scientific guidance of ecological program. Based on the 5-year long measured precipitation data and runoff data, it analyzes the changing relations. The results show that runoff directly relates with precipitation intensity, precipitation, land use and land cover, besides of configuration of geology, grate of terrain, thickness of soil. The analysis of precipitation-runoff process can offer physical basis for the setting up and validating of the model.4)sensitivity analysis of the region of interestThe paper chooses the automation method for sensitivity analysis of the model to decide on the most sensitive parameters of the area, which can be used to extend the characteristic parameters and set up the preferable scenarios. Parameters are calibrated by adjusting simulated parameter and processing of initial condition, boundary condition and restrict condition, to approaching analogy value and measured value for least error. Then, the paper checks the results for advancing investigative precision.(5)Simulate the runoff effect under the land use changingThe paper discusses the runoff effect under the land use changing, and simulates hydrological process based on hypothesis scenarios using calibrated model. The paper supposed five different land use scenarios, scenario1: most of the land use is forest and grass, scenarios 2: most of the land use is forest, sparsely forest and grassland, scenarios 3: the real land use of the region of interest, scenarios 4: most of the land use is range grass, sparsely forest and grassland, and scenarios 5: most of the land use is range grass. The water area will not change in all of the simulations. The results reflect that runoff will increase with grassland and forest decreasing. Grassland and forest of watershed can drop down the flood peak and achieve self-restraint of the water.