Study On Temporal And Spatial Variation Of Water And Eutrophication In Poyang Lake Area By Remote Sensing

Water resources are indispensable elements of human production and life,and the relationship with human beings is inseparable,so it is very important for its research.The Poyang Lake area not only contains the main lake area of Poyang Lake,but also contains a large area of the "five rivers" coccyx of the lake area,which covers a large number of farmland and city,floods in the study area,drought,eutrophication on the production and life of mankind great impact.Therefore,it is of great significance to study the waters of the Poyang Lake area and the eutrophication of water bodies.Based on the MSS image and Landsat TM images from 1976 to 2011,HJ satellite images from 2009 to 2016,and Landsat8 images from 2013 to 2016,the geometrical correction and atmospheric correction were carried out in this study.The water extraction model based on HJ satellite CCD image and the water extraction model based on Landsat series satellite are used to realize the extraction of the water body in the Poyang Lake area,and the accuracy of the water extraction of all the images is all based on the characteristics of the various images.In more than 80%,the extraction accuracy is higher.Through the study of the change of water body and the change of the interannual change,the study of the temporal and spatial changes of the water body is carried out.The area of the larger lake,the wet and the dry season is not changed in the southern part of the mountain,the Junshan lake,the Qinglan lake and the Yao lake The change of the area of the Poyang Lake area is mainly caused by the reclamation of the lake,the construction of the lake and the cofferdam,and the change of the water area is affected by the climatic factors such as precipitation.In the normal year,in addition to the main lake area outside the Poyang Lake area of the overall area of the downward trend.Through the comparison of the extensive quantitative method and the water body index method for the extraction of eutrophic water,the eutrophic water extraction model suitable for the Poyang Lake area is proposed.The Eutrophic extraction model of the Poyang Lake area was established based on the converted brightness,greenness,humidity component and NDVI index,and the thresholds were selected in detail.method.Based on the analysis of the water quality data of the main water quality monitoring station in the Poyang Lake area,the results are in agreement with the measured data,and the extraction precision is high.It is found that the eutrophication phenomenon in the Poyang Lake area is mainly concentrated in the south of the main lake area,and with the change of the water area,there is a tendency to move to the north,and the surrounding lakes in Nanchang are also analyzed.In the wet period,the frequency of eutrophication occurs near Kangshan Town is also large.The eutrophication of the waters of the Poyang Lake area is above 10 Km 2 and the area is not more than 25 km 2.The area of eutrophication is fluctuating at 15 km 2.