生态修复下金川矿区植被覆盖度及景观格局的变化

Changes of Vegetation Coverage and Landscape Pattern in Jinchuan Mining Area:A Study under the Ecological Restoration

矿区生态修复过程中植被覆盖度及其景观格局变化,可间接反映矿区植被生态修复效果。本研究基于NDVI数据,利用像元二分法提取甘肃省金川矿区植被覆盖度,分析矿区植被景观格局变化,探究矿区植被修复效果,为后续植被恢复与保护及生态修复措施调整提供参考借鉴。结果表明:(1)2005—2020年金川矿区植被覆盖度从24.15%提升至30.99%,且高覆盖植被占比逐步上升。(2)研究区植被覆盖度呈“西高东低”的空间格局,植被覆盖明显改善的区域为北部防护林、中部湿地公园及西南部矿山公园,退化区域为西北部建设用地扩张区域。(3)金川矿区植被覆盖度景观破碎化随时间先增加后降低,景观多样性与均匀度有所提升。高覆盖与低覆盖的景观破碎化程度较低且集聚性高,呈集中连片分布特征;较高、中等及较低等级植被覆盖景观破碎化程度较高,但近5年破碎化速度有所减缓,呈不规则形状零散分布在市区内。今后应继续因地制宜地修复矿区植被,提高植被的自我恢复能力,增强植被生态系统稳定性与可持续性。

Based on NDVI data,this study extracted the vegetation coverage of Jinchuan mining area in Gansu Province by pixel dichotomy.The change of vegetation landscape pattern in the area was analyzed.Moreover,the effect of vegetation restoration was explored.The results show that,(1)the vegetation coverage of Jinchuan mining area increased from 24.15%to 30.99%during 2005 and 2020,and the proportion of high vegetation coverage increased gradually.(2)The spatial pattern of vegetation coverage in the area is that of high in the west while low in the east.The areas with obvious improvement in vegetation coverage are the northern shelter belt,the central wetland park,and the southwest mine park,and the degraded areas are the northwest construction land expansion areas.(3)The landscape fragmentation of vegetation coverage in the area first increased and then decreased with time,and the landscape diversity and evenness improved.The landscape with high coverage and low coverage has a low degree of fragmentation and high concentration,which is characterized by concentrated contiguous distribution.The degree of fragmentation of high,medium,and low-grade vegetation cover landscape is high,but the fragmentation speed has slowed down in recent five years,and it is scattered in the urban area in an irregular shape.