拉西瓦水电站建设对区域景观格局与生境质量的影响

评价水电站建设对景观格局与生境质量的影响对改善当地生态环境质量、减少水土流失具有重要意义。以拉西瓦水电站周边区域为研究区,基于2000年、2005年、2010年、2015年土地利用和DEM等数据,利用移动窗口法分析水电站建设各时期景观格局指数的时空演变规律,结合InVEST模型研究生境质量的时空分布特征,探究水电站建设对周边区域景观格局与生境质量造成的影响。在此基础上,采用空间自相关方法分析生境质量的时空聚集模式,探讨高原地区水电站建设对周边区域生境质量时空聚集造成的影响。结果表明:(1)在2005—2010年水电站建设中期,景观格局指数空间分布发生明显变化,2000—2005年水电站建设前期与2010—2015年水电站建设后期几乎不变。(2)研究区的生境质量数值为0.3～0.7,在2005—2010年水电站建设中期,"中等"生境质量的面积占比由35.15%变成45.26%,"良好"生境质量的面积占比由48.23%变成40.28%。(3)2000年、2005年、2010年、2015年4期生境质量的Moran’s I均为正值,在空间上呈现非随机性,"高—高"空间聚集主要为河流与裸土地地区,"低—低"空间聚集为稀疏草地与建设用地地区,2005—2010年在水电站位置的西北区域,"不显著"空间聚集转为"低—低"空间聚集。

Impact of Laxiwa Hydropower Station Construction on the Regional Landscape Pattern and Habitat Quality

Evaluation the influence of hydropower station construction on landscape pattern and habitat quality was of great significance to improve local ecological environment quality and reduce soil erosion. Taking the surrounding area of Laxiwa Hydropower Station as the research area, based on the land use and DEM data in 2000, 2005, 2010 and 2015, the temporal and spatial evolution law of landscape pattern index in each period of hydropower station construction was analyzed by the moving window method, and the temporal and spatial distribution characteristics of habitat quality were studied by combining with invest model, so as to explore the impact of hydropower station construction on the regional landscape pattern and habitat quality of surrounding areas. On this basis, the spatial autocorrelation method was used to analyze the spatial and temporal clustering degree of habitat quality, and the influence of hydropower station construction on the spatial and temporal clustering degree of habitat quality in surrounding areas in plateau area was discussed. The results showed that:(1) In the middle period of hydropower station construction from 2005 to 2010, the spatial distribution of landscape pattern index changed significantly, while that in the early period of hydropower station construction from 2000 to 2005 and the late period of hydropower station construction from 2010 to 2015 remained almost the same. (2) The habitat quality of the study area was mainly between 0.3 and 0.7, during the middle period of hydropower station construction from 2005 to 2010, the proportion of the area with medium habitat quality increased from 35.15% to 45.26%, and the proportion of the area with good habitat quality increased from 48.23% to 40.28%. (3) Habitat qualities of Moran''s I in 2000, 2005, 2010 and 2015 were all positive, showing non randomness in space. The "high-high" spatial aggregation was mainly river and bare land area, and the "low-low" spatial aggregation was mainly sparse grass and construction land area. From 2005 to 2010, the "insignificant" spatial aggregation turned to "low-low" spatial aggregation in the northwest of the hydropower station location.