大同半干旱煤矿区植被覆盖度时空演化研究及影响因素分析

Spatial-temporal Evolution and Affecting Factors of Vegetation Coverage in Datong Semiarid Coal Mining Area

基于像元二分法，以归一化植被指数（ NDVI值）为参数提取半干旱煤矿区-大同矿区，1999～2010共12个年份植被覆盖度，运用空间变差函数及其分维数为刻度指标，分析12年间大同矿区植被盖度的空间相关性和空间异质性的变化，并利用山西大同矿区口泉沟、云岗沟两个采矿点的煤炭开采量，分析植被空间分布变化的影响因素。结果表明，（1）大同矿区植被盖度呈“下降-振荡上升-迅速上升”的趋势，在空间上集聚分布性先增加后减弱，空间差异先增大后减小，在南-北方向表现得尤为明显；（2）煤炭开发对矿区植被的扰动呈现整体性特征；（3）煤炭开发对植被的扰动效应与其产量成正比，煤炭开发的扰动作用是大同矿区植被盖度时空演化的内在因素，而采煤棚户区搬迁则是外在推手。

Vegetation coverage data in semiarid Datong coal mining area from 1999 to 2010 were extracted by using the pixel dichotomy method, with normalized difference vegetation index values serving as parameters.Spatial var-iogram and fractal dimension were applied as calibration indexes to describe variation of spatial correlation and spa-tial heterogeneity of the vegetation coverage in Datong coal mining area during 12 years.The coal production of Kouquan Valley and Yungang Valley in Datong coal mining area were used to analyze influential factors of spatial variation of vegetation.Generally variation tendency of the vegetation coverage in Datong coal mining area were de-clining, oscillatory rising and rapid rising.The main findings were as follows： （1） The vegetation coverage in Da-tong coal mining area exhibited a“declining-oscillatory rising-rapid rising” trend, a gradual weakening of the spa-tial autocorrelation and aggregation effects, a constantly decreasing spatial disparity, and a generally discrete sta-tus.These features were especially obvious in the south-north direction.（2） Coal mining activities disturbed veg-etation in the mining area in overall features.（3） The disturbance effects caused by coal mining were proportional to the coal production capacity, which was the internal factor of the spatial-temporal evolution of the vegetation cov-erage in the Datong coal mining area.The relocation of mining shanty towns served as the extrinsic factor.