Quantifying the impacts of roads on Isfahan landscape pattern using gradient analysis and landscape metrics methods

Quantifying urban landscape is fundamental for monitoring and assessing ecological and socioeconomic consequences of urbanization. Expansion of roads is a significant factor driving urban landscape change. The aim of this research is quantifying impacts of roads on Isfahan city landscape. To achieve this aim، land use map of Isfahan was created in 6 classes: urban، green spaces، agricultural، bare land، road and water. Combining gradient analysis with landscape metrics were used for analyzing landscape pattern. Landscape metrics were computed along a 15×3 km2 east-west transect cutting across city center with a moving window technique. In this study، we used 3 metrics: percentage of landscape (PLAND)، Patch Density (PD)، Largest patch index (LPI). To assess road impacts، urban class was merged with road، and then comparing these two transects، road impacts were assessed. The results showed that the urban landscape pattern of Isfahan was greatly changed when road corridors were merged with urban patches. Merging road and urban patches resulted in a sharp reduction in patch density and a rise in largest Patch index. Landscape patch density is significantly correlated with road percent coverage and the most important effect of road corridors on urban landscape is increased habitat fragmentation.