Evolution and degradation mechanism of surface vegetation coverage in typical ecologically fragile mining areas in western China
HUANG Yanli,GUO Yachao,QI Wenyue,LI Junmeng,WANG Jiaqi, OUYANG Shenyang,WU Laiwei
中国矿业大学 矿业工程学院中国矿业大学 煤炭资源与安全开采国家重点实验室新疆工程学院 矿业工程与地质学院燕山大学 河北省重型装备与大型结构力学可靠性重点实验室
生态本底脆弱的西部矿区已成为我国煤炭资源的主产区,采动影响下矿区生态环境日趋退化,其中最直观的体现就是对地表植被的影响。为揭示采矿扰动区地表植被变化状况,以枣泉煤矿为研究靶区,选取了10景连续的SentineL-1A雷达影像数据和93景SentineL-2A光学数据,基于小基线集差分干涉测量技术(SBAS-InSAR),结合一元线性回归分析和相关系数,研究了工作面开采过程中地表下沉特征,分析了工作面开采沉陷区与非沉陷区植被NDVI时序演化特征,评估了采矿扰动下矿区植被覆盖度时序演化趋势,并对采损植被退化机制进行了剖析。研究表明:2014年-2021年枣泉矿区地表植被NDVI呈物候性周期变化趋势,矿区植被覆盖度总体呈改善状态;工作面开采当年地表植被开始出现退化,退化程度较低,在采后2-3年退化最为明显,随后逐渐缓慢恢复,总体经历了轻微退化期、显著退化期以及逐渐恢复期等变化过程。土壤有机质、含水率是影响矿区植被发育的重要土壤理化性质因子,采矿扰动区地表下沉、裂缝发育引起有机质、全氮、全磷等地表土壤理化性质的改变以及采动影响下地下水位下降是造成工作面植被退化的重要原因,温度和降雨量也对矿区地表植被发育状态有重要的影响。研究成果为西部生态脆弱矿区采损植被生长状况的科学诊断、矿区植被修复时机的确定提供了理论与数据支撑。
The western mining area with fragile ecological background has become the main production area of coal re⁃ sources in China, and the ecological environment of the mining areas has been degraded under the influence of mining,the most obvious impact is on vegetation. In order to reveal the changes of surface vegetation in the mining disturbance areas,the Zaoquan coal mine was used as the target area,the 10 views of continuous SentineL-1A radar im⁃ age data and 93 views of SentineL-2A optical data were selected. Based on Small Baseline Subset InSAR (SBAS-In⁃ SAR) technology,combined with one⁃dimensional linear regression analysis and correlation coefficients,the surface subsidence characteristics during mining were studied,the NDVI time⁃series evolution characteristics of vegetation in the subsidence area and non⁃subsidence area of the working face were analyzed.Also,the time⁃series evolution trend of vegetation cover in the mining area under mining disturbance was assessed,and the degradation mechanism of min⁃ ing⁃damaged vegetation was analyzed. The results show that the surface vegetation NDVI of the Zaoquan mining area from 2014 to 2021 showed a trend of physical cycle,and the overall vegetation cover of the mining area was improved The surface vegetation began to degrade in the year of mining,the degradation degree was low,and the degradation was most obvious in 2 - 3 years after mining, and then slowly recovered. In general, the vegetation cover has gone through the process of slight degradation,significant degradation and gradual recovery. Soil organic content and soil moisture content are important factors affecting the development of vegetation in the mining areas. The changes in surface soil physical and chemical properties such as organic matter,total nitrogen and total phosphorus caused by sur⁃ face subsidence and fracture development in the mining disturbed areas,as well as the decline of groundwater level un⁃ der the influence of mining are important causes of vegetation degradation at the surface of working face. Temperature and rainfall also have an important influence on the development status of surface vegetation in mining areas. The stud⁃ y results provide theoretical and data support for the scientific diagnosis of the growth of mining⁃damaged vegetation in the ecologically fragile mining areas in the western China and the determination of timing for vegetation restoration in the mining areas.
ecological fragile mining area;mining subsidence;vegetation coverage;linear regression;spatiotemporal e⁃ volution
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会