| Mine resources are an important part of our national economy, so mine resources development and mine geo-environment protection have always been concerned. Because of the shortage of land, there are a number of residences located in the surroundings of mining area in our country. Especially some mining cites are directly constructed in the mining area, the mining activities are directly threatening the people’s lives and property who live in the mining area. Therefore, some scholar recently proposed the idea of mine geo-environmental risk assessment (MGERA). Its theoretical basis is the common international mine geo-environment impact assessment (MGEIA) and geo-hazards risk assessment theory. Geo-environment problems during the mining process is the main concerned point of MGERA, and it usually assesses the mine geo-environment risk (MGER) from the potential consequences to life safety and property loss caused by geo-environment problems. It is very meaningful to instruct mine resource development and mine geo-environment protection from the perspective of slowing down the MGER. It is not only the basic demand to ensure the normal live and work of mining area residents, but also is the important action to build the Beautiful China.Since the risk assessment process involving quantitative evaluation, when mining area regional evaluation overlays with a variety of geo-environment problems evaluation, the quantitative evaluation become very complex. Therefore, it needs to combine creative thinking with modern technology to assess the MGER. We chose the Daye mining city and Chengui Town certain mine, which belongs to Daye in the southeastern Hubei key mineralization area, as the typical study area to assess the MGER by RS and GIS. This MGERA method system contains two assessment scales, which are regional MGEIA and monomer MGERA, and it has important guidance and reference to the geo-environment protection and mine resources development of similar mining cities and key mineralization areas.After regional MGEIA and monomer MGERA, this thesis has acquired the achievements as follow:(1) The MGERI of Daye mining area:according to the mining present situation and mine geo-environment survey of Daye mining area, The MGERI index system was established by considering geo-environment background, geo-environment problems and mining activities, which include 10 evaluation factors. We employed the fussy comprehensive assessment method to assess the geo-hazard susceptibility (GHS) before mining and the MGEI after mining respectively. We compared and analyzed the GHS under the natural state with the MGEI under mining state.It indicates that:Under the natural state, the geological hazard high easy-happening area takes up 3.29%, medium easy-happening area takes up 12.55%, relatively low easy-happening area takes up 24.53% and low easy-happening area takes up 59.62%. Under the mining state, the mine geo-environment severely impacted area takes up 13.63%, less severely impacted area takes up 22.96%, relatively slightly impacted area takes up 33.95% and slightly impacted area takes up 29.46%. In addition, we put forward the related suggestions for the high impacted area.(2) The monomer MGERA process and method system:The MGERA consists of the hazard assessment of geo-environment problems and the vulnerability assessment of the element at risk. The key problem is the quantification of the intensity of geo-environment problems and the rapid recognition of the related attributes of the element at risk. Taking the common tailings reservoir of Daye mining area as an example, we proposed to combine the physical model test and the Tsunami Squares numerical simulation method to quantify the intensity of the debris flow after the tailings dam break. And we put forward rapid the recognition method of the required attributes to assess the vulnerability of the element at risk by the field sampling survey.(3) The example application of typical monomer MGERA:Taking the Chengui Town certain mine as an example, after field survey, we think the tailings dam and mining blast vibration are main geo-environment problems that will threaten people’s lives and property. The tailing mud depth, maximum velocity and blast vibration velocity are used as the intensity parameters to quantify the hazard of these two geo-environment problems.196 buildings concentrated areas (including 89 single building in front of tailing dam) have been done the monomer mine geo-environment vulnerability assessment (MGEVA) and the monomer MGERA.The results indicate that:the tailings dam in extreme conditions, under 1/4 and 1/2 collapse gate conditions, the number of high, moderate-high, medium, low and no risk buildings respectively are 7 and 21,14 and 22,11 and 9,0 and 0,57 and 37. For high-risk area, we put forward the safely spending the flood season, tailings recycling, residence relocation and other risk management suggestions.The MGERA based on RS and GIS is an effective way to realize the quantitative regional and multi-geo-environment problems risk assessment. In addition, it is also the expansion of the sudden geological hazard risk theory in the field of regional geo-environment assessment. We established relatively perfect mine geo-environment risk assessment and management theoretical system by the case study on Daye mining area and Chengui Town certain mine. It also provides practical MGERA process and technical means for other similar mining cities and key mineralization areas. |
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