典型露天矿区生态环境遥感评价

Remote sensing evaluation of ecological environment in typical open-pit mining areas

研究露天矿区生态环境演变及其时空变化规律,对露天矿区生态环境保护和建设绿色矿山具有重要意义。以平朔矿区为例,基于Landsat 5/8影像和气象数据,采用RSEI指数及改进的CASA模型监测1989—2019年平朔矿区生态环境演变并分析生态恢复力与RSEI、NPP的关系,结果表明:平朔矿区1989—2019年生态环境呈变好趋势,差等级面积从1989年的33.00 km^(2)减少到2019年的16.75 km^(2),优和良等级面积分别增5.51 km^(2)和5.66 km^(2);研究区采矿面积从1989年的10.63 km^(2)增加到2019年的65.84 km^(2);2019年土地复垦面积比2002年增加了14.97 km^(2);基于线性加权构建表征生态恢复力大小的综合指数Z分析表明30 a间矿区生态恢复力逐渐增大,且该指数与NPP和RSEI呈显著正相关(P<0.01)。利用自然间断法将综合指标分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4级,分别表示生态恢复力由低到高,30 a间生态恢复力低的I区面积呈下降趋势,生态恢复力高的IV区面积呈增加趋势,说明30 a间平朔矿区复垦效果显著。

It is of great significance to study the evolution of ecological environment and its spatiotemporal variation in open-pit mining area.Taking Pingshuo mining area as an example,based on Landsat Image and meteorological data,RSEI index and improved CASA model were used to monitor the evolution of ecological environment in Pingshuo mining area from 1989 to 2019,and the relationship between ecological resilience and RSEI and NPP was analyzed.The results showed that:The ecological environment of Pingshuo mining area showed a trend of improvement from 1989 to 2019.The area of poor grade decreased from 33.00 km^(2) in 1989 to 16.75 km^(2) in 2019,and the area of excellent and good grades increased by 5.51 km^(2) and 5.66 km^(2) respectively.The mining area in the study area increased from 10.63 km^(2) in 1989 to 65.84 km^(2) in 2019;the area of land reclamation in 2019 increased by 14.97 km^(2) compared to than in 2002.The comprehensive index Z based on linear weighted analysis showed that the ecological resilience of mining area increased gradually in 30 years,and the index was positively correlated with NPP and RSEI(P<0.01).The comprehensive indexes of reclamation are divided into four categories ofⅠ,Ⅱ,ⅢandⅣ,representing the ecological resilience from low to high respectively.The results show that the area ofⅠwith low ecological resilience decreases andⅣwith high ecological resilience increases during 30 years,indicating that the reclamation effect of Pingshuo mining area is remarkable in 30 years.