为了流域的生态保护修复和可持续发展,其景观格局脆弱性的研究变得尤为重要。以黄土丘陵沟壑区汾河流域为研究对象,通过构建景观格局脆弱度指数,利用质心及标准差椭圆、探索性空间数据分析(ESDA)的方法,对近25年来流域景观格局脆弱度时空演变及空间关联性进行了分析。结果 表明:(1)1990—2015年汾河流域景观格局脆弱度总体上呈现先上升后下降的趋势,脆弱度高的区域空间分布由相对集中变得较为分散;(2)1990—2015年景观格局脆弱度质心不断向北移动,标准差椭圆呈“东北—西南”的空间分布格局,脆弱度空间分布越发分散;(3)研究区各时期景观格局脆弱度全局Moran's I表现为一定程度的正相关,且相关程度先上升后下降;(4)研究区景观格局脆弱度局部空间自相关在3个时期发生了明显的变化,高低值区域呈现空间集聚,且分布范围由相对集中转变为较为分散。地形、河流等自然因素影响汾河流域景观格局脆弱性的空间分布; 政策导向、社会经济活动等人为因素加速了景观格局脆弱性的变化。
For the ecological protection and restoration and sustainable development of the river basin, the research on the vulnerability of its landscape pattern becomes particularly important. By constructing the landscape pattern vulnerability index and using the centroid and standard deviation ellipse, using exploratory spatial data analysis method as well, taking the Fenhe River Basin in the Loess hilly and gully region as the study area, we investigated the spatial and temporal evolution and spatial correlation of the landscape pattern fragility in the past 25 years. The results show that:(1)the landscape pattern fragility in the Fenhe River Basin generally demonstrated the increasing trend at first and decreasing trend later, and the spatial distribution of areas with high fragility became more dispersed from relative concentration from 1990 to 2015;(2)the barycentre of landscape pattern fragility moved northward gradually, and the standard deviation ellipse showed the spatial distribution pattern of ‘north-southwest', and the spatial distribution of fragility was more dispersed from 1990 to 2015;(3)the Moran's I of the landscape pattern fragility in the study area showed the positive correlation at a certain degree, the correlation degree increased at first and then decreased;(4)the spatial autocorrelation of the landscape pattern fragility in the study area had changed significantly in three periods: the high and low value areas showed spatial agglomeration, and the distribution trend converted to more dispersed pattern from relatively concentrated pattern. Natural factors such as topography and rivers affect the spatial distribution of landscape pattern vulnerability in Fenhe River basin, and human factors such as policy guidance and social and economic activities accelerate the change of landscape pattern vulnerability.
