Shuitu baochi tongbao (Apr 2023)
Vegetation Spatial and Temporal Dynamic Characteristics and Ecological Quality Assessment in Metal Mine Areas of Desert-Steppe
Abstract
[Objective] The impacts of a metal mine on the surrounding grassland were studied, and the ecological environment was evaluated using remote sensing technology as a significant aid to ecological restoration and environmental protection of mining areas. [Methods] The study was conducted at a desert-steppe gold mine located in an ecologically fragile area. Spatial and temporal dynamics of normalized difference vegetation index (NDVI) in the mine area were analyzed based on long time series remote sensing data to conduct a comprehensive evaluation of the ecological quality of the study area using the remote sensing ecological index (RSEI). [Results] The impacted area of desert-steppe gold mining was determined as the area with a radius of 5 km outward from the mine boundary. There was a fluctuating increase in NDVI values in the mine and impact areas that varied with the duration of mining in the steppe from 2009 to 2021. The annual average value of NVDI within the mine area during the underground mining operation period was 51.9% higher than during the open pit mining operation period. In addition, the impact of open pit mining on vegetation in the study area was higher compared with underground mining. The RSEI values in the mining area and the impacted area initially increased, then decreased, and then stabilized, resulting in an overall non-significant increase. The spatial distribution of RSEI indicated that the areas with poor ecological environmental quality in the mine and impact areas were mainly the waste dump and surrounding area. [Conclusion] Gold mining influenced the surrounding desert grassland within a radius of 5 km from the mine. The ecological environment of the mine and the impacted area gradually improved through management efforts during mining. Ecological restoration and environmental management of the waste dump and the surrounding area should be strengthened during the process of mine ecological construction.
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