A survey of the effect of scale on the sensitivity of landscape metrics

Development of remote sensing (RS) and GIS techniques and that of landscape metrics in the late 1980s have caused to introduce a new dimension in the landscape ecology arena (the relationship between spatial patterns and ecological processes). However, scale dependence of some of landscape metrics and RS systems of different spatial resolution has resulted in particular attention into selection of an appropriate scale in the landscape ecology studies and correct interpretation of ecological processes. Hence, the present study has investigated the behaviors of some landscape metrics in relation to changes in scale. Accordingly, the effects of the scale (pixel size and extent) on those landscape metrics which indicate trends of vegetation cover class was discussed applying Landsat images in Isfahan city and its surrounding (an area of ​​960 thousand hectares). For this purpose, behavior of NP, PD, LSI, MPS, ED, MNN, MSI and TCAI have studied through changing the size from 30 m to 60, 120, 240 and 480 and extent from 300 ha to 600, 1200, 2400 and 4800. The results of this study indicated sensitivity of these metrics except TCAI in relation to the scale factor. This type of studies and attention to the spatial scale have indicated that it could play an important role in identifying the impacts of ecological processes, predicting the ecological functions (landscape modeling) and reducing the uncertainty in landscape ecology studies.