汾河流域景观破碎化时空演变特征

以1990年、2000年、2015年遥感影像解译数据为基础,利用Fragstats 4.2软件分别采取标准法和移动窗口法获取最佳分析尺度;在此基础上探索各景观指数空间分异特征,揭示流域景观破碎化时空演变过程;采用空间自回归模型分析景观破碎化的影响因子。结果表明:随着粒度和幅度的改变,部分景观指数呈现一定规律性,90 m栅格大小、900 m方形窗口尺寸为研究区最佳分析尺度;斑块密度、蔓延度、有效网格大小、香农多样性指数在三个时期均存在空间集聚效应,且空间集聚类型分布形态具有较强的相似性;1990-2015年汾河流域景观破碎化空间分布格局发生明显变化,破碎化集聚区域呈现碎斑化;坡度、高程、距建设用地距离是影响三个时期流域景观破碎化的主要影响因素。

The spatio-temporal evolution characteristics of landscape fragmentation in Fenhe River Basin

There is fragmented land and fragile ecological environment in the loess hilly and gully region. With the rapid population growth and socio-economic development in recent years, the degree of fragmentation has been further aggravated. Therefore, based on the interpretation data of remote sensing images in 1990, 2000 and 2015, this paper uses Fragstats 4.2 to obtain the best analysis scale combined with the standard method and moving window method. On this basis, the spatial differentiation characteristics of each landscape index are explored; The spatial and temporal evolution process of watershed landscape fragmentation is revealed; The spatial autoregressive model is used to analyze the impact factors contributing to landscape fragmentation. The results show that with the change of grain size and extent, some landscape indices show a regularity to certain degree. The 90 m grid size and 900 m square window size are the best analysis scales in the Fenhe River Basin; patch density, contagion, effective grid size, and Shannon's diversity index have a spatial agglomeration effect in the three periods, and the spatial agglomeration type distribution has strong similarity. From 1990 to 2015, the spatial pattern of landscape fragmentation in the study area has obviously changed; the slope, elevation and distance from the construction land are the main factors affecting landscape fragmentation of river basin during the three periods. The research results can provide reference for landscape fragmentation analysis in Northwest China, and provide basis for future regional landscape pattern optimization and effective land management.