Study On Water Quality Indicator Simulation Model Building In The Poyang Lake Based On Satellite Remote Sensing

Poyang lake is the largest freshwater lake in China.It plays an important role in water conservation,improving local climate,regulating the water level of the Yangtze river and maintaining the ecological balance in the surrounding area.In 2009,the development of poyang lake ecological economic zone was set as a national strategy,and the environmental problems are facing serious test.It is of great practical significance to conduct the real-time dynamic monitoring of the water quality of Poyang lake.In this paper,the Poyang lake region water pollution index simulation model was built based on satellite remote sensing data,combined with the water quality data from hydrology bureau of Jiangxi province in water quality monitoring sites.Moreover,which can realize the purpose of monitoring and forecasting the dynamic of water pollution in Poyang lake region,providing a reference for Poyang lake region water environment management platform.The main conclusions are as follows:(1)construction of the simulation model of total phosphorus.By comparing the precision of simulation model between HJ-1A CCD2-based and Landsat5 TM-based remote sensing image,the relative error of LANDSAT TM 5 simulation model was between 10.34%?10.34%,the average relative error was 21.16%,the relative error of HJ-1A CCD2 simulation model was 8.70%?28.57%,the average relative error was 14.30%.The simulation model based on environmental monitoring satellites,in general,was slightly better than Landsat simulation model.The environmental monitoring satellite in water quality simulation study is operational in practice,can be used in water quality parameters-total phosphorus(TP)simulation monitoring research.(2)construction of ammonia nitrogen(NH3-N)simulation model.By comparing the precision of simulation model between HJ-1A CCD2-based and Landsat5 TM-based remote sensing image,the relative error of Landsat5 TM simulation model was between 6.67%?42.86%,the average relative error was 27.45%,the relative error of HJ-1A CCD2 simulation model was 8.96%?25.71%,the average relative error was 16.42%.The simulation model based on the environmental monitoring satellite was slightly better than the land satellite simulation model,which can be used for the research of the simulation monitoring of water quality parameters-ammonia nitrogen((NH3-N).(3)agricultural non-point source pollution model was established based on SWAT model of non-point source pollution model using the province elements watershed basic information database,through the coupling of non-point pollution and model.The model parameter calibration and verification results demonstrate that the province based on the model elements within the basin hydrological simulation match with the actually measured value well.The runoff simulation achieves the higher simulation accuracy,with rate of Ens in regular and validation period higher than 0.6.Both the TP rate and the duration of the validation period were higher than 0.5.In terms of NH3-N,whose corresponding indexes were higher than 0.6,the simulation effect was satisfactory.After calibration and verification,the SWAT model can objectively reflect the runoff,TP and NH3-N loss law of non-point source pollution.The model can therefore be used in simulating and predicting the basin runoff,TP and NH3-N loss of non-point source pollution.