Evolution analysis of vegetation cover under the disturbance of rare earth mining: A case in Lingbei mining area

More and more attentions are paid to the problems which caused by ionic rare earth mining vegetation degradation and serious ecological environment. In Lingbei rare earth mining area, Dingnan County is regarded as the research object, the Landsat images of 23a as data source, monitoring and analyzing the spatiotemporal evolution of vegetation coverage under the disturbance of rare earth mining. In order to improve the reliability of monitoring and analyzing, using dimidiate pixel model (DPM) and linear spectral mixture model (LSMM) to extract vegetation coverage of mining area, vegetation coverage extraction accuracy is validated by Pleiades image with a 0.5 m spatial resolution. The results show that: LSMM takes the spectral characteristics of unique tailings into consideration, it is more suitable for the mining area vegetation coverage extraction; from 1990 to 2013, average vegetation coverage maintains a high level; concentrating trend of the low vegetation coverage areas is very obvious, mainly for bare surface due to the pool/heap leaching rare earth mining, ecological problem is still serious; vegetation degradation mainly caused by rare earth mining, in-situ leaching reduced the direct destruction of surface vegetation, but due to leakage of leaching liquid inevitably, may lead to a greater range of vegetation degradation; average vegetation coverage of each year increased with the mining area as the center, the effect area of coverage involves around 300 to 400 m, in-situ leaching on the surrounding vegetation effect is less than tank/heap leaching.