spatial–temporal monitoring of ecotonal belt using landscape ecological indices in the central elburz region: remote sensing and gis analysis

iran has mountainous landscapes and half of its surface is occupied by highlands. moreover, iran is an arid country and deserts are located at lower altitudes. most metropolitan areas are positioned in mid-altitudes between mountain and desert. cities grow upwardly toward the highlands under pressures of urbanization and desertification. foothill ecotones are a zone between upland mountains and midland plains. upwardly sprawl of urban centers has transformed the structures and functions of these ecologically strategic belts. in this article, we analyzed the transformational trend of the ecotonal zone in the southern slopes of the central elburz (tehran-karaj urban region). landsat 7 etm+ (2000) and 8 oli (2013) are used to monitor spatial and temporal variability of landscape metrics. the land covers are grouped into four classes: vegetation cover, open space, built area, and water body. seven landscape metrics are used including: np, cap, mps, aw-mps, mnnd, para, and te. our results indicate that np, aw-mps, te, and para increased whereas cap and mps decreased. these results are a sign of the fragmentation process across the ecotonal strip.