煤炭井工开采对干旱荒漠区植被动态变化的影响

我国西北干旱荒漠区生态环境脆弱，煤炭开采活动严重地破坏植被和影响生态环境，而煤炭井工开采对干旱荒漠区植被动态变化的影响尚不明确。以灵武市为例，采用遥感技术和野外实地调查相结合的方法，分析2000-2019年间煤炭井工开采对植被动态变化的影响。结果表明：灵武市的植被主要以沙蒿（Artemisia salsoloides）、柠条（Caragana korshinskii）和芨芨草（Achnatherum splendens）等荒漠植物为主；2000-2019年间，植被覆盖度（FVC）和绿度变化率（GRC）表明灵武市植被整体呈现改善趋势；归一化植被指数（NDVI）与年降水量（P）和年平均风速（S）等气象因子显著相关，表明气候因子对区域植被动态变化起主要作用；煤炭开采区侵占草地和灌丛面积，使得土地利用类型发生变化，生态环保政策的实施对于区域土地利用类型的变化和植被改善具有重要作用。实地调查分析表明煤炭开采改变了矿区植物群落结构，植被盖度和物种多样性指数均在煤炭开采后1-4a呈下降趋势，5-9a为上升趋势，10a自然恢复后与对照区的变化趋势一致，说明在自然条件下煤炭开采区植被恢复经历了退化期、改善期和初步恢复期等过程。这些研究结果为西北干旱荒漠区煤炭井工开采矿区植被恢复和生态环境建设提供了理论基础。

Effects of the underground coal mining on the dynamic changes of vegetation in arid desert area

The ecological environment in the northwest arid desert areas of China is fragile. Coal mining activity severely damaged vegetation and affected the ecological environment of mining area. However, the impact of the underground coal mining on the dynamic change of vegetation in the arid desert area is not yet clear. In this study, taking Lingwu city as an example, the dynamic changes of vegetation and its relationship with underground coal mining from 2000 to 2019 was analyzed using a combination of remote sensing technology and field investigation. The results showed that the vegetation in the region of Lingwu was mainly desert plants such as Artemisia salsoloides, Caragana korshinskii, and Achnatherum splendens. From 2000 to 2019, the fractional vegetation coverage (FVC) and the greenness rate of change (GRC) showed that the vegetation was slight improved. The normalized vegetation index (NDVI) had significant correlation with meteorological factors such as annual precipitation (P) and mean wind speed (S), indicating that meteorological factors played a major role in the dynamic change of vegetation in northwest arid desert areas. Coal mining activity encroached on grassland and shrubland areas, and led to changes in land use types, while the implementation of ecological environmental protection policy played important roles in the changes of land use types and vegetation improvement in this region. The field investigation showed that the plant community structure in coal mining area was changed by the coal mining activity. The vegetation coverage and species diversity index both showed a downward trend within 1-4 years after coal mining, and an upward trend within 5-9 years, and tended to be consistent with the control area after 10 years natural restoration. This indicated that the succession of vegetation under natural restoration in coal mining areas experienced three stages: the degradation, improvement and initial recovery. All these results provided a theoretical basis for vegetation restoration in coal mining areas and ecological environment construction in the northwest arid desert areas.