A measurement of Urban sprawl in spatial dynamics of Rasht ,Iran

Urban sprawl, is the encroachment of urban land uses on non-urban land, which in recent years has become one of the challenges of planning the spatial development of cities around the world. The purpose of this study is to identify and measure the dimensions and urban sprawl reflections of urban surface in Rasht. The method of this research is descriptive-analytical. In order to measure and study the urban sprawl, first land use maps were created by using Landsat satellite images in four classes (urban and built areas, water and paddy areas, forests and agricultural lands as well as gardens) .They, also, used spatial metrics (Class Area, Number of Patch, Patch Density, Total Edge, Edge Density, Mean Shape Index, Area Weighted Mean Shape Index, Euclidean Nearest-Neighbor Distance, Proximity Index, Aggregation Index) in two levels of class and landscape to calculate the Rasht city Urban sprawl surface via FRAGSTATS software. The results of the research show that urban areas have grown increasingly and several urban plots have emerged. Along with this growth, agricultural land and paddy fields have lost their spatial cohesion and integrity and have turned into considerable number of plots. The coefficient of 103% increase in urban class over a period of 26 years (1993-2019) indicates the rapid change of spatial dynamics of the city into physical dispersion, which, in turn, is generally associated with land use change, land cover change and destruction of natural and terrestrial resources outside and around the city.