【作者】 刘英； 雷少刚；

【Author】 LIU Ying;LEI Shao-gang;Institute of Land and Resources,China University of Mining and Technology;Engineering Research Center,Ministry of Mine Ecological Restoration Education;

【机构】 中国矿业大学国土资源研究所； 矿山生态修复教育部工程研究中心；

【摘要】 植被生态系统是指示矿山土地生态系统健康与演替方向的主要标识。理解采煤矿区植被生态系统的时空演替特征以及驱动因子是矿区植被退化区识别、判断矿山生态良性演替以及人工干预合理程度的关键。本文采用200幅多时相Landsat遥感数据,借助于植被指数与植被覆盖度,基于不同时序植被覆盖度格点回归斜率、标准差和植被覆盖等级转换矩阵等,分析了研究区植被覆盖度时空演变及其驱动机制,剖析了研究区、中心矿区和恢复区植被覆盖度变化趋势和波动程度,进而揭示随着时间变化采矿活动与植被覆盖度间的响应。结果表明:不同年份研究区植被覆盖度及其等级空间分布整体上具有一定相似性,矿山采复活动在打破了区域植被覆盖度时空演变格局。研究区植被覆盖度以低等(Ⅲ)、中等(Ⅳ)为主,按多年均值计算,两者之和占研究区总面积的80%以上.研究区植被覆盖度呈增加、不变与减少的区域面积比为5.69:4.55:1,相关系数在-0.8933～0.3291之间,负值范围的-0.9266～-0.4629与植被退化程度呈现不同程度显著性相关。露天煤炭开采对植被损伤最严重,露天采区、排土场及其周边2.81 km范围内的植被覆盖度呈显著下降趋势。井工开采引起地表塌陷,破坏植物生长立地条件,土壤持水能力降低,地下水位下降,最终影响了植物的生长。2014-2016年塌陷面积增加了203.10 km2;2013年7月-2015年8月研究区地下水位平均降低了72.92%;从开始塌陷到塌陷结束,土壤表层10-100 cm含水量平均降低了12.06%。在0～8 m范围内,NDVI随地下水位的增加而显著降低,大于8 m时,地下水位变化对NDVI的影响不大。植被重建工作对提高矿区植被覆盖率具有重要作用,重建后约6年,恢复区植被生长进入稳定期,为了保证植被恢复的可持续性,建议在受到破坏和干扰的情况下,干旱矿区的植被恢复管理周期应保证为6年以上。煤矿区植被覆盖的提升有赖于矿区社会压力减少和生态恢复力提高两方面。研究成果将为露天煤矿及其所在区域生态环境科学保护与决策、恢复和治理提供信息支撑。更多还原

【Abstract】 The vegetation ecosystem is the main symbol indicating the health and succession direction of the mine land ecosystem.Understanding the temporal and spatial succession characteristics and driving factors of vegetation ecosystem in mining area is the key to identify the vegetation degradation area,to judge the rational degree of mine ecological succession and human intervention.In order to study the spatial and temporal evolution of vegetation coverage and its driving mechanism,200 Landsat-NDVI remote sensing data with spatial resolution of 30 m and temporal resolution of 16 days were used to obtain vegetation index and vegetation coverage.Based on the lattice regression slope(θ_slope),standard deviation（SD） and conversion matrix of vegetation coverage in different time series,the variation trend and fluctuation degree of vegetation coverage in the study area,central mining area and restoration area were analyzed,and the response between mining activities and vegetation coverage with time was revealed.The results showed that:The vegetation coverage of Shendong Mining Area showed an upward-trend as a whole,and the spatial distribution of vegetation coverage and its grades in different years is similar.The spatial-temporal evolution pattern of vegetation coverage is broken by mining and restoration activities.The vegetation coverage of the study area is mainly medium low（Ⅲ） and medium（Ⅳ）,which account for more than 80% of the study area.The area ratio of increased,unchanged and decreased vegetation coverage was 5.69:4.55:1.The correlation coefficient was between-0.8933 and 0.3291.The correlation was not significant in the range of positive value,but significant in the negative part.The vegetation damage is most serious in open pit coal mining.The vegetation coverage of the open pit mining area,the dumping site and the surrounding 2.81 km area showed a significant downward trend.The surface subsidence caused by underground mining,destroyed the site conditions of plant growth,decreased the soil water holding capacity,decreased the groundwater level,and finally affected the growth of plants.Vegetation reconstruction plays an important role in improving the vegetation coverage in the mining area.6 years after the restoration,the vegetation growth has entered a stable period.In order to ensure the sustainability of vegetation restoration,it is suggested that the management cycle of vegetation restoration in arid mining areas should be guaranteed to be more than 6 years under the condition of damage and disturbance.The improvement of vegetation coverage in coal mining area depends on two aspects:reducing social pressure and improving ecological resilience.The research results will provide information support for scientific protection,decision-making,restoration and management of mining area ecological environment.更多还原