Coal Mine Flood Risk Assessment in Wuda Coal Mining Area --Using GIS and Remote Sensing Data and Hydrological Model.

摘要

In China, coal mine accidents were mainly caused by gas and water inrush. Recently, the direct economic loss caused by coal mine flood has been ranked the first among all kinds of coal mine disasters. Reducing water inrush accidents become the main direction and aiming of coal mine security control. From the statistics of coal mine disasters, we learned that the coal mine flood disasters have become the most dangerous mine disaster. There is, therefore, an urgent need to design and provide a coal mine flood risk assessment timely and accurately for mine companies to prevent and deal with the coal mine flood. Traditional approaches investigate the geological condition and find out the exactly numbers and width of fissures caused by coal mining or coal fires burnt. However, the shortcomings of these methods are time consuming, difficult to repeat, and costly to apply over large areas, especially, for many coal mine area located in isolated region, high up in the mountains, in dense forests, and other inhospitable terrains. Hence the use of GIS technology and remote sensing data, particularly satellite remote sensing with a capability of repeated observation of the earth surface, was considered as a very effective approach to detect, analyze and monitor information of mine flood in coal mine area over a large areas.;In this research a risk assessment model was proposed to assess the mine flood risk in Wuda coal mine area using RS, GIS techniques and basic hydrological model. First of all, we analyzed the major factors causing coal mine flood in Wuda coal field, based on the geological and hydrological data. According to the investigated material and the experiences from geologists and coal mining experts, four main criteria including water sources, surface condition, water conductors and water containers as well as fourteen factors were selected to participate the assessment, among which, rainfall, stripping digging pits and fissures were considered as the three main factors to cause mine flood in Wuda coal mine area. The rainfall and sinks information were easily to derive. However, the fissures information was difficult to obtain. Based on the analysis of investigation, the positive correlation between fissures and coal fires or subsidence was obtained. Therefore, the coal fire factor and ground subsidence factor were imported to indicate the fissures information. Then, a method for deriving these impact factors was proposed for coal mine flood risk assessment model. After obtaining the all factors related information, the weights of these factors were calculated by pair-wise comparison method, which depend on the specialists' opinions. A risk assessment analysis approach based on AHP was created for combining these factors and calculating the results.;Finally, based on the result from risk assessment model, a risk assessment indication map was generated using GIS software. By comparing our assessment result with the Wuda coal flood risk map from Shenhua Group, we noticed that the distribution and levels of coal mine flood risk are similar. Some other auxiliary techniques, for instance, the geological drilling and geological radar detection, were used to validate the result of our study. These techniques also proved the final result is reasonable and acceptable. After the investigation and evaluation, some conclusions and suggestions, were proposed for coal mine companies to avoid or reduce the risk from coal mine flood.;The results indicate that the methodology is effective and practical; thus, it has the potential to forecast the flood risk for coal mine flood risk management. Therefore, it can be used as a final risk assessment model for mine flooding in coal fire area. In the future, we will conduct such risk analysis to mitigate the impact from coal mine flood disasters.;Keywords: coal fire, subsidence, fissure, risk assessment, coal mine flood, AHP.