典型地貌景观指数的多尺度效应分析——以山西省运城市为例

景观指数作为定量描述景观特征的指数,具有明显的尺度效应.进行景观指数的尺度效应研究,对进一步理解格局与尺度之间的关系具有重要意义.本文以TM影像为基础,选择山西省运城市平原、丘陵、山地及综合地貌4种不同地貌类型,对7个常用景观指数进行了多尺度效应分析.结果表明:不同地形上斑块密度(PD)、景观形状指数(LSI)、结合度(COHESION)3个指数有明显的粒度效应,随粒度的增加呈现逐渐减少的变化趋势;最大斑块指数(LPI)、周长面积比分维数(PAFRAC)、景观聚集度(CONTAG)和Shannon多样性指数(SHDI)4个指数随粒度的增加几乎不发生变化.不同地貌的景观指数随幅度的变化规律比较复杂,景观形状指数(LSI)随幅度的增加呈现逐渐增加的趋势,其余6个指数在较小幅度范围内变化比较复杂,但随着幅度的增大有逐渐趋于平稳的趋势.针对研究区不同地貌类型,其景观指数在不同粒度和幅度下有较大区别,可以根据景观指数值的大小来区分地貌的复杂程度.

Analysis of Multi-scale Effect of Landscape Indices of Classical Landforms in Yuncheng City,Shanxi Province

Landscape indices,as quantitative description to landform characteristics,have obvious scale effect and have being used widely.Researches on the scale effect of landscape indices have important significance in understanding the relationship between pattern and scale of landforms.Based on TM images,we choose four different geomorphologic types,i.e.plain,hill,mountain and complex landform in Yuncheng City,Shanxi Province,and seven landscape indices to analyze the multi-scale effects.Firstly,we did the resample from landform images to get ten grain sizes and twelve extent sizes;secondly,according to the response curves of landscape indices of different grain and extent sizes to the four landforms,we analyzed the grain effect and extent effect of seven common landscape indices.The result showed that： patch density（PD）,landscape shape index（LSI）,patch cohesion index（COHESION） show a gradual downward trend with increasing of grain size with different geomorphologic types,largest patch index（LPI）,perimeter-area fractal dimension（PAFRAC）,landscape contagion（CONTAG） and Shannon diversity index（SHDI） have no significant changes.All landscape indices showed complicate changes with the changed spatial extent in different geomorphologic types.Landscape shape index（LSI） gradually declined with the increasing spatial extent,the other landscape indices curve changed rather complicatedly in the smaller spatial extent and showed no significant changes in the larger spatial extent.In addition,according to the different landforms,the landscape indices have obvious distinction in different grain and extent sizes,so we can distinct the complexity of different landforms by landscape indices.