黄土区大型露天煤矿企业土地复垦质量控制研究

Land reclamation quality completion standards for large opencast coal mine enterprises in Loess areas

根据《中华人民共和国土地管理法》《土地复垦条例》《土地复垦质量控制标准》的要求,采用遥感影像解译、实地监测与室内分析相结合的方法,以及中国地质大学(北京)土地复垦团队1986—2016年在平朔矿区长期试验示范、跟踪监测评价的成果,旨在建立符合地域特色、具有可操作性的煤矿企业土地复垦质量控制标准。分析矿区1986、1996、2000、2004、2009、2013年的土地利用变化,以及18个典型耕地、林地、草地土壤剖面的土壤环境质量和土壤肥力指标。结果表明,地貌重塑是复垦土地质量的基础,土壤重构是复垦土地质量的核心,植被重建是复垦土地质量的保障。土地复垦质量控制的基本要求是:地貌稳定系数≥1.3,土壤侵蚀模数≤1000 t·km^(-2)·a^(-1),控制在黄土区允许的土壤侵蚀量范围内,耕地面积比例占60%左右、林草用地面积占30%左右,海拔高程不超过1500 m;土壤污染物含量达到《绿色食品产地环境质量标准》(p H>7.5),耕地和林草地的有效土层厚度不小于120 cm和60 cm,容重1.2~1.4 g·cm^(-3),pH值7.0~8.5,有机质含量不低于10.0 g·kg^(-1);选择先锋植物与适生植物,进行草、灌、乔不同复垦模式的合理配置,形成有效控制地表径流的乔木层、灌木层、草本层、枯落物层和土壤层。

On the basis of the requirements of the Land Administration Law of the People＇s Republic of China, the Land Reclamation Regu-lations and the Completion Standards on Land Reclamation Quality, the objective of this study was to establish completion standards for the land reclamation quality of coal mine enterprises with the features of regional characteristics and operability. The methods of remote sensing image interpretation and a combination of field monitoring and indoor analysis were used in this study, and we adopted the accumulated ex-perimental, demonstration, monitoring, and evaluation results for the period 1986 to 2016 in the Pingshuo mining area, obtained by the land reclamation team of the China University of Geosciences（Beijing）. Land-use changes in the mining area for the years 1986, 1996, 2000, 2004, 2009, and 2013 were analyzed, as were soil environmental quality and fertility indices derived from 18 soil profiles, including those from arable land, forest land, and grassland. Landform reshaping is the basis of reclaimed land quality,whereas soil reconstruction is the core, and vegetation restoration is the guarantee. The basic requirements of land reclamation quality completion are as follows：the geomor-phic stability coefficient should not be less than 1.3;the soil erosion modulus should not be greater than 1000 t·km-2·a-1, which is within the permitted range of soil erosion amount in loess areas; the proportion of cultivated land area should be approximately 60%, and forest and grassland should comprise approximately 30%;the elevation should be less than 1500 m;soil contaminant contents should comply with the Green Food Origin Environmental Quality Standards（pH〉7.5）, namely, an effective soil thickness of arable and grasslands greater than 120 cm and 60 cm, respectively, a bulk density between 1.2 and 1.4 g·cm-3, a pH value between 7.0 and 8.5, and an organic matter content greater than 10.0 g·kg^-1;pioneer and adaptable vegetation should be selected to configure different reclamation modes of grass, shrub, and tree;moreover, the tree, shrub, herbaceous, litter, and soil layers should be established to effectively control surface runoff.