Study On The Evolution Of Aquatic Vegetations And Its Driving Mechanism Of Wuliangsuhai Lake Based On Extracting Remote Sensing Information

The formation mechanisms of Lake Eutrophication and its controlling measures are the research priorities of the restoration and reconstruction of current domestic and international wetland ecosystem. Moreover, one of the most important characterizations of Lake Eutrophication is the abnormal proliferation of aquatic vegetation. Therefore, monitoring the distribution and size of large aquatic vegetation in a timely manner can reflect the degree of eutrophication of water body in real time. It is of great scientific significance and practical value to prevent further deterioration of water quality of the water column, the degradation of aquatic vegetation and the functional decay of ecological system.In this paper, Wuliangsuhai Lake, which is the biggest freshwater lake located in the Basin of Yellow River, was selected as the study area. ENVI image processing system and ArcGIS platform were used to analyze and interpret the remote sensing images of the same season in1989,1995,2001,2002,2007and2010. We got the spatial variation and evolution trend of aquatic vegetation in1989-2010. Based on the results, the natural factors and human-driven factors affecting its change were studied. The main conclusions of the paper are as follows:1Decision Tree Classifier used to extract aquatic vegetation information from remote sensing image is more effective.2In Wuliangsuhai, the evolution trend of aquatic vegetation is that the emergent plants in reed for the absolute advantage in population is slowly increasing, and the submerged plant area is decreasing year by year. Additionally, the correlation between water body eutrophication and submerged plants area is significant.3A large number of withdrawal of water in irrigation area, industrial wastewater as well as urban and rural domestic sewage were discharged into Wuliangsuhai, which were the main reasons for eutrophication and the evolution of aquatic vegetation in the lakes.4After the water saving projects were conducted in the irrigation area, the increasing eutrophication of water quality was alleviated and the growth of submerged aquatic plants was inhibited somewhat.The results in this study can provide theoretical support and technical guidance on the eutrophication control and sustainable use of aquatic resources in Wuliangsuhai.