Research On Non-point Source Pollution Loads In Xianjuemiao Reservoir Basin Based On GIS

With the development of society and economy, situation of water pollution isbecoming increasingly serious in China recently. Non-point source pollution is animportant aspect leading to water pollution, its wide distribution, great uncertainty, strongambiguity and difficulty of monitoring make it hard to study with, especially in thoseareas which extremely lack of data. GIS technology is capable of many advantages, suchas quick analysis speed, convenient to automation, visualization and informatization,which make the stuy of non-point source pollution based on GIS technology as a majortrend in recent years.To save manpower and resource, improve timeliness and acceptation, this papertook Xianjuemiao reservoir basin as an example, extracted essential data for non-pointsource pollution research from the latest remote sensing data and solved the problemwhich non-point source pollution research mostly rely on local statistic data. As to dataanalysis and processing, this paper used GIS technology and programming tools whichcould improve the accuracy and efficiency of data analysis, and achieved automation andvisualization of data analysis partially, which also laid foundation for informationizationof non-point source pollution research.Firstly, this paper identified eight land use type recognition factors which were rivernet, elevation, slope, surface roughness and remote sensing images of blue, green, red,infrared bands based on ASTER GDEM data and Landsat-8remote sensing image data.Then divided land use types after sampling analysis, and areas of water body,bare-building land, paddy field, dry land, forest and shrub are10.23km2,8.71km2,24.72km2,39.84km2,280.16km2and66.84km2respectively. The average confidence levelof land use types classification is92.63%. According to the land use types, HWSD soiltexture data, rainfall and pollutant concentrations, this paper worked out pollution loads ofthe basin in2013with the use of ArcGIS and SCS model, The loads of NH4+-N, TN, TP,BOD, and COD in2013are20.271t,42.470t,0.845t,65.047t and269.630t respectively.