平朔安太堡大型露天矿区土壤质量演变过程分析

Investigation on the Evolution of Soil Quality in the Antaibao Large-scaled Opencast Area

本文对安太堡大型露天矿区的采矿和复垦过程中土壤质量的变化状况进行了调查,结果表明:采矿造成原地表结构的彻底改变,土壤质量变化经过退化和恢复两个阶段。在整个过程中,土壤的物理、化学和侵蚀性状都发生了变化,并且土壤的恢复过程很缓慢。

The study area, Antaibao Opencast （39°23＇～39°37＇N, 112°10＇58＂～113°30＇E）, is located in Shuozhou City of north Shanxi Province, a triangle zone in the contiguous areas of Shanxi Province, Shaanxi Province and Inner Mongolia Autonomous Region in the Loess Plateau, China, and it belongs to a temperate arid continental monsoon climatic area. The opencast area is characterized by the extensive distribution of loess, sparse vegetation and serious water and wind erosion, and is one of the regions with vulnerable ecological environment in China. The Antaibao Opencast is the first large-scaled opencast in the study area, the mining area is about 60 km^2, and the service time is 92 years. The geographical environment has been significantly changed since mining from 1985. In this paper, the changes of soil quality during mining and after reclaiming in the Antaibao Opencast area are investigated. A 15-year stationed observation is carried out in the plots of 10 m×10 m for arbors, shrubs and mixed forests and of 5 m×5 m for herbs and vegetation-uncovered lands, and the samples are sampled from 5 sampling sites of each plot. The results reveal that the evolution of soil quality in the study area can be divided into two stages, i.e., the degradation stage and restoration stage. In the degradation stage, the soil quality is changed in a burst way, the physical and chemical properties of soil are seriously destroyed and degraded. In the restoration stage, the lands are reclaimed and the soil is improved by artificially improving soil and increasing the erosion-resistant capability of lands so as to recover the productivity of lands as soon as possible. However, such improvement and restoration are very slow, the soil quality is much poorer after the lands are reclaimed for 8 years than that before disturbing. Moreover, the virtuous evolution of soil quality may be reversed if natural disasters or irrational human activities occur. Therefore, the land reclamation and the regeneration of ecological environment should be paid great attention to.