Study On Water Quality Influence Factor And Pollution Comprehensive Assessment Method Of Coal Mine Subsided Water Area

With increasing of the scale of coal exploitation and coal-electricity integrated complex, the water problem in mining area becomes increasingly prominent and the lack of water resource has restricted the industry to develop. Meanwhile, it has formed coal mining subsided water area in large scale by coal production where the groundwater is shallow. So it is of great scientific value and practical significance to study the subsided water quality change regularity and the contor and influence factor, exactly appraise the water quality, and predict the change trend of water environment. It can save the resource, increase the utilization rate and avoid over-exploited of underground.In order to study the evolvement characteristics of water quality in different subsided water area with different subsidence age, Panxie mining area of Huainan city is taken in this dissertation. According to the traits of subsided water environment and controlling and influencing factors of water quality, Zhangji, Xieqiao and Panyi mining subsided water areas with different subsidence age and good closed condition are selected to monitor the water indexes and research the evolvement characteristics regularity with time increasing. The results show that total phosphorus, total nitrogen, total hardness and heavy metal elements have cumulative effect. The formation of subsided water quality traits is mainly influenced by mining pollution source, agricultural pollution source and microseism.According to the controlling influence of microseism factor to the subsided water quality, dynamic signal monitoring system with data continuous collection, large storage capacity is selected to do microseism monitoring experiment to 1612 (1) working and goaf section of Panyi mining area. The results show that microseism signal can be received from the ground in thick loose layer condition and the signal frequency is 37HZ. To find the water quality regularity influenced by microseism, similar materials simulation theory and physical model simulation method are used to study the water quality. The conclusion is that suspended solids absorbed lots of heavy metal i as and deposited. Besides, the content of heavy metal elements decreased till in stability as microseism time increasing.In addition, the comprehensive assessment model of subsided water quality is built with the combination of principal component analysis method and fuzzy comprehensive evaluation method, according to the reasonableness of assessment indexes and accuracy of the model. In the assessment process, the inverse indicator of "countdown method" is used in principal component analysis method and "logarithmization method" is used to the indexes from the non-dimensional aspect, enhancing the contribution of the first principal component rate. The fuzzy comprehensive evaluation factor in the evaluation of selected indicators is carried out to improve the use of the cumulative variance contribution rate of more than 85% evaluation factor to determine the selection.The combination style of GIS and environmental assessment model is analyzed in this dissertation, using ArcGIS Engine and C # to set up a water quality assessment information system. In order to make the comprehensive assessment of water quality visual, Universal Kriging interpolation method is used to achieve the transformation of monitoring data from point to surface. The Universal Kriging model of ArcGIS Engine is used to solve the distribution map of water pollutants in the east and west subsided water areas of Panyi mine, which can reflect the actual state of the environment truly and accurately when the water quality monitoring data are adequate.The mining subsidence theory and the probability-integral method are used to establish mathematical model for predicting the subsidence area. Forecasting the future development trends of subsided water area in the mining plan and mapping the annual sinking isoline chart of Panji mine area, it will make the administrators have a clear recognition of the subsided water area development trend of Panji mining area.