Effects of mining activities and climate change on land ecosystem in Gobi mining area:A case study of Zhundong Coal Base

Owing to the coexistence of coal enrichment,sparse vegetation,fragile ecology and arid climate in Xinjiang,it was urgent to solve the contradiction problem between coal exploitation and ecological protection.Therefore,the Zhundong Coal Base was selected as the case study,and the Arid Remote Sensing Ecological Index (IARSE) was extracted from the Landsat multi-spectral remote sensing data from 2000 to 2020.Then,the spatio-temporal variation ARSEI was revealed by pixel-by-pixel trend analysis.Finally,the effect of mining and climate change on the quality of land ecosystem in Gobi mining area was analyzed with the help of multiple regression model and residual analysis.The results show that ① in the past 20 years,the average IARSE was 0.403 8,mainly medium (44.22%) and poor (41.27%),but excellent level only accounted for 1.57%.The proportion of degradation area (41.19%) was much higher than that of improvement area (7.05%).Specially,the proportion of mine scale degradation was more than 85%.② The I′ARSE simulated by climatic conditions showed a decreasing pattern from southwest to northeast.Climate change had improved I′ARSE since 2006.The improvement area was mainly concentrated in the east of Dajing,the northeast of Jiangjunmiao and the north of Xiheishan,while the degradation area was mainly distributed in Wucaiwan.③ Mining had a negative effect on the quality of land eco-system,with an average residual of -0.128.The degradation induced by mining was concentrated in the new mining area and on both sides of the new road,showing a degradation pattern with the characteristic of “point-line-net-surface”.④ The impact of climate change on the quality of land ecosystem in Gobi mining area was greater than that of mining activity,but their effects on IARSE improvement area and degradation area were different.For improved areas,the contribution rates of climate change and mining were 88.53% and 11.47%,respectively.But for the degraded areas,the contribution rates of climate change and mining were 58.68% and 41.32%,respectively.In conclusion,the nature reserve should be avoided in the coal exploitation of Gobi mining area.To avoid further ecological degradation along the road,the construction of unnecessary road networks should be reduced,and the ecological protection and restoration on both sides of the road also should be emphasized.Finally,the favorable climate trend in recent years could be applied,some necessary artificial induction should be supplemented.Through the above measures,the overall protection,systematic restoration and comprehensive management could be effectively promoted in the Gobi mining area.