Non-point Source Pollution Reasearch Based Onlanduse Change Inliangjiang New Area

In our country, as point pollution control of industry and living, non-point sourcepollution become the main factors of river pollution.The change of land use is the mainfactors influencing the changes of agricultural non-point source pollution. The changeof land use changes the hydrological characteristics andthe direction and velocity of thewater flow on the surface, thus affecting the material cycle and energy distribution inthe soil.Chongqing Liangjiang new area is one of the three state-level new district.Thenewarea isthe bridgehead and the opening portalofChinese central and western regions.The significant changes have taken place in the area of land use, resulting inthedeterioration of water ecological environment. The improvement of the Liangjiangnew area water environment,and pollution control of the secondary river in Chongqingbecome the common demand of the government and the people. In view of these,theresearches of the non-point source pollution caused by the land use change of theLiangjiang new area propose the optimal land use pattern. The control of the pollutionof the Liangjiang new area is of great significance.Based on the GIS technology and the SWAT model, and combining with hydrology,remote sensing, the research method of landscape ecology, the environment of theLiangjiang new area is simulated, and the different land use and landscape pattern arealso analyzed, which propose the best land use for the future development of theLiangjiang new area and the management pattern. In this paper, the main researchresults are as follows:①Besed on the on-site investigation, such as collection of the Liangjiang new areapollution sources in the domestic wastewater, livestock and poultry breeding,agricultural fertilizer, urban sewage and wastewater plant effluent data.And theirpollution is calculated. In this paper, water quality of the outlet of the20rivers andlakes of the Liangjiang new area are comprehensively assessed by usingthe standardsofsurface water functional division and nutrition state grading.②The spatial database and attribute database of the Liangjiang new area non-pointsource pollution model is constructedusing ARCGIS9.0and ArcView extensionmodule.The digital elevation model (DEM) is established. Then the river network andthe watershed division are addressed.The images ofthe Liangjiang new area in2006, 2009,2011and2013are analyzed using Erdas Image9.2.And combining with the landuse plan of theLiangjiang new area in2020, the fifth land use map is obtained. tometeorological database and soil database arecreated by using dew02, PcpSTAT, SPAW,MATLAB and Excel.③Sensitivity analysis, calibration and verification are used to analyze the SWATmodel. The regional suitability evaluationof the model is also analyzed. Firstly,thesensitive parameters of the runoff, sediment and pollutant simulation parametersaredetermined, then adjusting the parameters. The relative certainty coefficient R2andthe Nash-suttcliffe simulation efficiency coefficient of runoff, sediment and pollutantsimulation evaluation are adopted. The results show that the SWAT model is suitable forthe simulation area.④The simulation ofthe land use change of non-point source pollution. The landuse conversion matrix in2009and2011are established.The direction of various typesof land conversion isdetermined. the change characteristics of non-point source underthe land usein2006,2009,2011and2013are analyzed. The land use change of theZhongzui river basin is analyzed, including the sediment, total nitrogen, totalphosphorus, the change of the spatial distribution.The recent non-point source pollutioncontrol measures are proposed.⑤Combination the land use plan ofthe Liangjiang new area in2020, the pollutantoutput changes of the20riversof the Liangjiang new area in2013and2020areanalyzed. The land uses of the Zhongzui riverin the different situation are established.Comparingtheir influence on non-point source pollution,the best management style ofthe forward development of Zhongzui river is determined.It can be extended to thelong-term development of the Liangjiang new area.