锡林郭勒盟大型露天煤矿区地质环境时空演化评价

Spatio-temporal evolution evaluation of geological environment of large open-pit coal mine areas in Xilin Gol league

内蒙古锡林郭勒盟大型露天煤矿区经过20多年的开发,产生了一系列矿山地质环境问题,矿区地质环境在一定程度上遭到破坏,因此,开展大型露天煤矿区地质环境时空演化评价可为矿区生态地质环境修复提供参考。本文对锡林郭勒盟3个大型矿区进行地质环境时空演化评价。首先通过现场调查,明确了研究区主要的矿山地质环境问题,包括植被覆盖度下降、土地压占(排土场和工业场地)、地形地貌景观破坏(露天采坑)和含水层破坏等4类;其次利用遥感影像定量获取了2000—2020年之间的矿山地质环境问题信息,并建立了矿山地质环境评价指标体系;然后应用层次分析法确定了矿山地质环境评价指标的权重,并通过基于GIS的影响指数模型对矿山地质环境影响进行了评价和区划,探讨了矿山地质环境时空演化规律。研究结果表明:(1)3个大型矿区植被覆盖度下降区域的面积、排土场压占土地面积和露天采坑破坏地形地貌景观面积随时间不断增加;(2)大型矿区采矿对地质环境的影响划分为无影响区、轻微影响区、一般影响区、较强影响区和强烈影响区5个等级分区;(3)3个大型矿区地质环境时空演化规律基本相同,不同影响区的空间分布特征和面积随时间变化的规律不同。

After more than 20 years of development in the large open-pit coal mine areas in Xilin Gol league,Inner Mongolia,a series of mining geological environmental problems have been generated and the geological environment of the mine area has been damaged to some extent,therefore,the evaluation of the spatial and temporal evolution of the geological environment of the large open-pit coal mine areas can provide a reference for the ecological and geological environment restoration of the mine areas.This study evaluates the spatial and temporal evolution of the geological environment in three large mining areas in Xilin Gol league.Firstly,through site investigation,it was clarified that the main mining geological environment problems in the study area mainly include four categories,such as vegetation coverage decline,land occupation(drainage field and industrial sites),topography landscape destruction(open-pit mining)and aquifer destruction.Then remote sensing images were used to quantitatively obtain information on mine geological environment problems between 2000 and 2020,and a mining geological environment evaluation index system was established.After that,the hierarchical analysis was applied to determine the weights of various geological environmental problems,and the impact index model based on GIS was used to evaluate and zone the impact of mine geological environment and explore the law of spatial and temporal evolution of mine geological environment.The results of the study show that:(1)The decreasing vegetation coverage,the area of the land occupied by the soil discharge site and the area of the open pit destroying the landscape of topography and geomorphology are increasing with time in the three large mining areas.(2)The impact of mining on the geological environment in the large mining area is divided into five class sub-areas:no impact area,slight impact area,general impact area,stronger impact area and strong impact area.(3)The spatial and temporal evolution pattern of the geological environment in the three large mining areas is basically the same,and the spatial distribution characteristics and the area change pattern of different impact areas with time are different.