宜昌市西陵区景观格局适宜粒度判别与效应分析

Appropriate Granularity Discrimination and Effect Analysis of Landscape Pattern in Xiling District, Yichang City

基于GIS和RS的技术支持,以土地资源利用数据为主,以宜昌市西陵区2017年GF-1高精度遥感影像为辅,二者相结合并以ArcGIS为技术手段.提出研究该区域景观格局的适宜粒度,分析不同粒度大小对不同类型景观指数的影响.研究结果表明:在200~330m粒度范围内,250m的粒度大小最适宜该区域的景观格局指数的研究.研究分析景观格局指数对粒度效应的响应,结果表明:类型水平景观指数中聚合指数等5个景观指数,粒度效应变化曲线随粒度的增加呈现下降趋势;类型水平景观指数中平均形状指数等7个景观指数,粒度效应变化曲线随粒度的增加差异较大,无可循规律;整体景观水平景观指数中凝聚度指数等8个景观指数,粒度效应变化曲线随粒度的增加无巨大波动起伏,而指示不同地类斑块形状的景观形状指数粒度效应变化曲线随粒度的增加,呈下降趋势.从粒度效应曲线总体分析可得,同一景观指数的不同景观类型的粒度效应曲线变化趋势表现基本一致,除了细微的差异之外,并不存在明显的相反方向的变化趋势.从折点来看,不同类型景观下的景观指数,临界粒度基本相同,粒度240m为主要临界粒度.本研究确定了研究区域适宜的研究粒度阈值,表明了所选景观格局指数对粒度变化的响应程度大小.

Based on the technical support of geographic information system(GIS)and Remote Sensing(RS),the land use resources inventory data are the main,taking the high-precision remote sensing image of GF-1 in Xiling District of Yichang City as a supplement,combination of the two,using ArcGIS as a technical means.The suitable granularity of the landscape pattern in the region is proposed;and the effects of different granularities on different types of landscape indices are analyzed.The results show that:the grain size of 250m is the most suitable for the study of landscape pattern index in this region in the range of 200-330 m.The response of the landscape pattern index to the grain size effect is studied.The results indicate that:Five landscape indices,such as the aggregation index in the type horizontal landscape index,the grain size effect curve shows a downward trend with the increase of the grain size;there are 7 landscape indices such as the average shape index in the type horizontal landscape index.The variation of the grain size effect varies greatly with the increase of the grain size,and there is no rule to follow;there are 8 landscape indices such as the cohesion index in the overall landscape horizontal landscape index.The grain size effect curve does not fluctuate greatly with the increase of grain size,but the landscape shape index indicating the shape of different types of grains,while the grain shape effect curve of landscape shape index showed a downward trend with the increase of grain size.From the overall analysis of the grain size effect curve,the variation trend of the grain size effect curves of different landscape types of the same landscape index is basically the same,except for the slight difference,there is no obvious trend of the opposite direction.From the point of view of the breakpoint,the landscape index under different types of landscapes has the same critical grain size,and the grain size of 240m is the main critical grain size.On the one hand,this study determined the appropriate research granularity threshold for the study area;in the other hand,it indicates the degree of response of the selected landscape pattern index to the change of grain size.