基于时间分割算法的半干旱矿区植被动态特征分析

Analysis of dynamic characteristics of vegetation in semi-arid mining area based on time trajectory segmentation algorithm

分析半干旱矿区植被扰动与恢复动态特征,对矿区生态环境保护具有指导意义。以大柳塔煤矿为例,利用时间轨迹分割算法提取1994—2014年植被扰动与恢复时间及幅度特征,分析大柳塔煤矿各用地类型区植被空间分异及植被对煤炭开采响应特征。结果表明:1各类型区植被扰动/恢复发生的时间集中,各区域均于1995年发生大面积扰动与恢复;露天开采区第2次大面积植被扰动与恢复时间分别为2006和2009年,而工作面、重建区和小窑为2010年。幅度方面,建成区及工业广场植被扰动与恢复平均幅度最大,小窑扰动幅度与恢复幅度间差值最高。各类型区植被最大扰动持续时长均低于最大恢复持续时长。2工作面尺度,植被对煤炭开采扰动响应具有滞后性。工作面采后2 a植被扰动发生面积最大,而植被恢复面积随采后时长逐渐扩大。植被平均扰动幅度高于平均恢复幅度。时长方面,平均扰动持续时长为1.54~2.40 a,平均恢复持续时长为4.06~7.18 a。

Previous studies on vegetation change have difficulties to depict the detail information of dynamic characteristics of vegetation disturbance and recovery. This study takes Daliuta as a research area to extract the year of event onset,the duration and magnitude of vegetation disturbance and recovery based on time trajectory segmentation algorithm. The results indicated that： 1 At different production functional ozone scales,the area proportion of each time of event onset showed clustering over the year,large disturbance and recovery both distributed in all functional zones in1995,and the same as partial functional zones including mining face ozone,small coal pit area and vegetation reconstruction area in 2010. Large disturbance and recovery of open-pit mining in 2006 and 2009 respectively was occurred.Compared with other functional ozone,the industrial square and built-up area were seriously disturbed and recovered.The disturbance magnitude of coal pit was significantly higher than the magnitude of recovery,and the differences between disturbance and recovery magnitude were largest among different functional zones. 2 At mining face scale,thevegetation response to coal mining showed postponing. In addition,the largest range of disturbance occurred in the second year after exploitation. The magnitude of first vegetation disturbance after coal exploitation was higher than recovery magnitude,whereas the disturbance duration was less than the recovery duration. The range of duration of the first disturbance after coal exploitation is from 1. 54 to 2. 40,while is from 4. 05 to 6. 75 for the first recovery duration after coal mining.