Dynamic Monitoring Research On Water Environment Of The Coal Mining Subsidence In Huainan Panji

Panji mining area of Huainan city is located along the Huaihe River where network of waterways are heavy and the groundwater level is shallow. After long-term underground coal mining activities, there has been formed coal mining subsidence water area in a large scale. The water quality of the subsidence area is closely bound up with the local people’s livelihood, so it is of great practical significance to the coal mining subsidence water area by monitoring the change of the water quality of the waterlogged area in time. This paper took Panji mining area of Huainan city as the study area to monitor dynamically on land use and land cover change between1989and2010and especially analyze the tendency of the waterlogged area change. On the other hand, we established relationships between water-quality indicators of Panji Huainan Waterlogged area and the HJ-1/CCD2data and created inversion models to evaluate the water quality and water depth based on HJ-1imaging data. Consequently, we obtained the comprehensive evaluation result of the water environment in research area. The main research contents and results in this dissertation were as following:1, Because of the long-term underground coal mining activities the land use and land cover of the research area had a big change in the past20years from1989to2010. Through the analysis of the Landsat4/5/7images data the study area were divided into5classfications according to the maximum likelihood classifier (MLC). These five classifications were farmland、 urban land, subsidence water area-, river and coal heap which were diverse with each other in the false color composite of images of band4, band3and band2. We can find out obvious changes among three classification maps in different years. Through careful analysis, we can discover that the subsidence water change was the largest which was almost increased50times from39.15hm in1989to1904.04hm2and the proportion of the subsidence water to total area increased from0.2%to10%. In the past20years, there were524.97hm2urban land and1290.33hm2farmland transformed into subsidence water area, which was9.59%to the urban land and10.65%to the farmland in1989, and the increased area transformed from these two classifications in the past20years to the subsidence water area in2010was93.57%. The actual measurement and the field observation verified that the classification results and the total accuracy was more than80%.2^We established relationships between water depth of Panji Huainan Waterlogged area and HJ-1/CCD2data, and then create monitoring model of water depth with band1、band2、band3and band4which was the best for water depth estimation. Based on the model we developed the spatial distribution map which showed that the water depth of Panji Huainan Waterlogged area ranged from0to5m. The actual measurement verified that the average absolute accuracy was about0.5m and the average relative accuracy was more than80%.3、We established relationships between water-quality indicators of Panji Huainan Waterlogged area and the HJ-1/CCD2data. And then created monitoring models of Ch、SD、TP、TN and CODMn separately. Comprehensive Trophic State Index method was adopted in this research to evaluate the water quality of the research area. The results show that the research area was light-middle eutrophic in2011, which was accorded with the monitoring results published by local environmental protection departments.These research work demonstrated that the monitoring models that we established in the research area is reliable and could provide important technical support to realize the target of regional water quality remote sensing monitoring and early warning in the future.