Analysis of index system and state of ecological storage of typical large open-pit mines in Eastern Inner Mongolia：taking Baorixile，Yinmin and Shengli No.1 Open-Pit Coal Mine as examples

In order to study the ecological status of grassland mining area in different mining periods，three large-scale open-pit mines with similar natural conditions and mining status，including the Baorixile Open-pit Mine (20 years)，Yimin Open-pit Mine (36 years)，and Shengli No.1 Open-pit Mine (45 years)，with different mining years were selected. On the basis of the preliminary delineation of the ecologically sensitive areas in each mining area，the ecological service value analysis and the ecological storage state，process，capacity，pattern and condition indexes were used to comprehensively evaluate and compare the ecological storage effects of each mining area. The results showed that:① the variation range of ecological service value in 〖JP2〗Baorixile，Yimin and Shengli No 1 mining areas was -4 212.19，1 915.68 and -2 491.49 yuan /a，respectively. According to the ecological storage status index，the ecological service value per unit area of the mining area ecosystem of Baorixile，Yimin and Shengli No.1 open pit coal mine was degraded at a rate of 83.68，75.38 and 48.01 yuan/(hm2·a)，respectively. ② The conversion rate of ecological storage in the three mines was negative，the ecosystem showed a process of conversion from high service function to low service function，and the ecological storage process showed a negative trend. The ecological storage capacity values of Baorixile，Yimin and Shengli No 1 open pit coal mine are -410，-310 yuan/(hm2·a) and -240 yuan/(hm2·a)，respectively，among which Shengli No 1 mine had relatively good ecological storage capacity. The ecological storage pattern values of the three mines were close to each other. The ecological storage conditions of Baorixile，Yimin and Shengli No 1 open pit coal mine were 0.37%，0.69% and 0.62%，respectively. ③ The comprehensive index of ecological storage effect showed that the comprehensive index of Yimin mine was relatively high at 4.37，followed by Baorixile mine，and Shengli No 1 mine was relatively low〖JP〗 at 1.65，indicating that land use had the least impact on regional ecological storage of Yimin mine and the largest impact on Shengli mine. The results are helpful to take measures to slow down the accumulation of ecological effects in mining areas and promote the coordinated development of coal mining and grassland ecology.