Monitoring Of Mine Exploitation By Remote Sensing And Assessment Of Geological Environment In Northeast Chongqing

Mineral resources,as an important material basis,have made important contributions to the national economic construction.However,long-term and large-scale exploitation of mineral resources will inevitably lead to the destruction of ecological environment and even ecological imbalance,thus causing a series of ecological and environmental problems,such as landslide,collapse,debris flow,soil erosion,atmospheric pollution,occupation and destruction of land resources,etc.Not only do these problems restrict the development of national economy,but also threaten the safety of people's life and property.The northeast area of Chongqing belongs to the water conservation ecological function area of the Three Gorges Reservoir area,and it is an important ecological barrier in the northeast of Chongqing,which plays a significant role in maintaining the stability of the ecological environment in the upper reaches of the Yangtze River.In recent years,with the acceleration of economic development and urbanization in Northeast Chongqing,the demand for mineral resources has been increasing,and environmental problems have become increasingly prominent,which has brought great challenges to the construction of ecological civilization and sustainable development of social economy.Therefore,it is of great significance for the sustainable development of mineral resources and the protection of mine ecological environment in Northeast Chongqing to carry out remote sensing monitoring and mine geological environment assessment by using remote sensing and geographic information science.This paper,which taken the northeast area of Chongqing(Wushan,Wuxi and Fengjie)as the study area,carried out remote sensing monitoring of mining exploitation and geological environment assessment of mine by combinating RS and GIS.On the basis of the analysis of previous research results,in this paper,high-resolution remote sensing images from 2016 to 2018 were used as the data source,establishing a set of practical high precision remote sensing monitoring interpretation marks,extracting the mine environment information,quantitative monitoring and analyzing of mine environment dynamic change process.On this basis,a scientific and practical mine geological environment evaluation index system was constructed by selecting the appropriate evaluation index.Using grid method to divide the evaluation unit,using the analytic hierarchy process-rough set combination model to determine the index weight,and based on the multi-index weighted evaluation model,carring out the comprehensive evaluation of mine geological environment,and suggestions were put forward for mine geological environment problems in different zones.It provided technical support and decision basis for ecological environment protection and restoration in northeast Chongqing mining area.The main research achievements are as follows:(1)Using multi-type,multi-temporal remote sensing image as data sources,through digital processing of remote sensing images,a set of practical high precision the interpretation signs of mining exploitation types(stope,industrial square,solid waste,mine building)?geological disaster(collapse,landslide,debris flow)?restoration and governance were established,then carried on the remote sensing monitoring of mine environment in the study area,and established 2016-2018 mine environmental remote sensing monitoring database after the field inspection.(2)The dynamic changes of mine environment in the study area from 2016 to 2018 were analyzed.From the perspective of the mining state,the occupied area of producing mine decreased first,and then increased;the occupied area of dormant mine increased first,and then decreased;the occupied area of abandoned mine constantly increased.From the perspective of the occupied land of type,the total occupied area of mining activities constantly increased,and the occupied area of stope increased first,and then decreased;the occupied area of industrial square constantly increased,the occupied area of solid waste had no obvious changes;the occupied area of mine building constantly decreased.Different type of the occupied land showed different area increment and change amplitude,the sequence were as follows: industrial square > stope> mine building > solid waste;from the perspective of the rate of change,the sequence were as follows: mine building > industrial square > stope > solid waste.The number of restoration projects were on the rise,and the restoration area had increased substantially.From 2016 to 2018,there were 32,43 and 57 restoration projects of mine geological environment,and the restoration area were 38.58 ha,134.67 ha and 278.8ha,respectively.The main types of mine geological hazards were landslide,debris flow and collapse in the study area,and the number of mine geological hazards decreased year by year,which were 73,59 and 49 respectively from 2016 to 2018.(3)From the four aspects of natural geography,basic geology,mine exploitation activities and mine environmental conditions,13 indexes were selected,including slope,annual precipitation,drainage distance,vegetation fractional coverage,regional importance,geological structure,lithologic combination,mining method,mining minerals,mining intensity,area of occupied land,disasters,recovery and governance,then constructing the mine geological environment evaluation index system in the research area,and the evaluation index was quantified and classified,using the analytic hierarchy process and rough set to calculate the subjective and objective weights of the indexes,then introducing the game theory to determine the comprehensive weight of each indexs;the evaluation units were divided by grid method,and the quality index of mine geological environment was calculated by using multi-index weighted comprehensive model.(4)The results of this mine geological environment evaluation were divided into evident influence area,relatively evident influence area,general influence area and no influence area.The serious affected area was 19488.43 ha,accounting for 1.76% of the total area of the study area;the relatively serious affected area was 53805.64 ha,accounting for 4.86% of the total area of the study area;the general affected area was 370664.79 ha,accounting for 33.46% of the total area of the study area;the unaffected area was 663781.16 ha,accounting for 59.92% of the total area of the study area.Based on the above results,the study area of the mine geological environment was zoned,which provided a theoretical basis for guiding the sustainable utilization of mineral resources and the protection of mine ecological environment in Northeast Chongqing.