Research On The Impact Of Land Use Change On Runoff Based On Remote Sensing

Since the 80 s of last century, the relevant administrative departments to the Zhanghe River upstream basin were a series of water conservancy construction as the center of the transformation of human construction activities, such as the construction of reservoirs and irrigation area, groundwater mining, large and medium-sized water conservancy project construction, these human activities caused by the changes in watershed underlying surface factors that are affecting the formation of the basin runoff. The upper reaches of the Zhanghe river basin land use / land cover change and the validation of SWAT model in typical watershed applicability was studied by using remote sensing technology analysis. By means of runoff simulation method, the reference basin comparison method, the extreme land use SCS model law and legal analysis of five kinds of objects between varied effect on runoff. The simulation results of upper Zhanghe River Basin water resources management and allocation to provide a scientific basis.This study selected Zhuozhang River Basin as a typical watershed, Guan river reservoir, after Bay Reservoir and Zhangze reservoir for watershed water inlet to wall Hou hydrological station for the outlet of a watershed, simulated streamflow changes at different periods of the basin, the main contents and conclusions are as follows:Firstly, project group according to the proposed object classification, decision tree classification method and support vector machine classification method based on object oriented, making the upper Zhanghe River Basin in 1993, in 2006 and 2010 three periods of land use classification vector, using ArcGIS extracted from each object area. Using three models of over trend were analyzed, and the conclusion is drawn that: nearly 18 years of upper Zhanghe River basin land use change quickly,forest and water dynamic degree when wall sub basin in the maximum speed of change is also the fastest; cultivated land, urban construction land in Bay Basin change speed the fastest, the three land use mutual transformation between the type,are in varying degrees of influence watershed underlying surface, affecting the hydrological cycle.Secondly, choose the widely used SWAT(Soil and Water Assessment Tool) as a model of hydrological model in this study. By reading the relevant literature, the use of DEM(Digital Elevation Model(DEM) accumulation of basin boundary of pre cut,the bus length calculation, drainage network extraction accuracy, sub basin of accurate classification, soil type classification, hydrological model, meteorological data write, Zhuozhang River Basin of the SWAT model was constructed and the comparison of monthly runoff simulation.Thirdly, the inner diameter flow sequence of the typical basin presents a stage change. The ordinal cluster analysis method to find the cutoff point for 1985 and 2002,the transformation of human construction activities on runoff influence significant period 1986-2001 year, before 1985, the main factors of influence on runoff to climate change, after 2002 mainly double action of human activity and climate change.At last, using runoff simulation method, according to the watershed comparison method, the extreme land using and SCS model, analysis of typical watershed land use change on watershed runoff influence, the next year were precipitation and the decrease of forest change is closely related to, mainly by in returning farmland to forest, returning farmland to also grass policy influence. Waters of river basin production influences confluence, towns and building with more times, bare land arable land on basin runoff influence degree than higher.