Applying Landscape Metrics to Revise Land Degradation Model for Assessing Environmental Impacts
Document Type : Research Paper
Authors
Department of Environmental Science Faculty of Natural Resources University of Tehran Karaj, Iran.
Abstract
In the present study, in order to model the environmental impacts using landscape metrics; Guilan province was divided into 183 impact unit, and the Land Degradation Model was applied. In the next step, using the measures of (Related circumscribing circle, Perimeter-area ratio, Shape index, Fractal dimension index & Contiguity index) which were calculated by Fragststs, five models were developed based on stepwise modeling approach. Following from that, Akaike information criterion was applied to determine the most appropriate model. The results of this study showed that 39.78% of Guilan province is located in sensitive and susceptible areas. The highest physiological density was observed in Siahkal county. Regression models indicated that the amount of environmental degradation can be predicted using the weighted average of measures related to the landscape structure metrics: rcc (r2 = 0.437, p ≤ 0.05), contig (r2 = 0.615, p ≤ 0.05), frac (r2 = 0.505, p ≤ 0.05), shp (r2 = 0.499, p ≤ 0.05) and (r2 = 0.672, p ≤ 0.05). The most appropriate model, which was determined by AIC, was the model for the Perimeter-area ratio, and it had a good model validation result. Our findings revealed that applying the landscape metrics would be able to use for assessing the environmental impacts. In turn, it would decrease the degree of subjectivity in the landscape degradation model, as well. On the other hand, the use of landscape metrics, which can be easily and quickly calculated through land use or land cover maps, will greatly eliminate the need for extensive field work. Accordingly, using land degradation model will be more easily implemented in a much shorter time and at a lower cost to evaluate the environmental impacts.
Keywords
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