Investigating urban sprawl metrics and dynamics using RS and GIS case study: Gilan province, IRAN

Urban sprawl, meaning low density and inefficient development around cities, occurs as a result of population explosion and high immigration rate. Urban sprawl results in changes in land use and the loss of agricultural lands and open spaces around cities. In Iran, which has a high rate of urbanization, urban sprawl is considered as one of the main factors transforming land use. In particular, it is critically important to examine this phenomenon in Gilan province since it is one of the country's main agricultural zones and it also enjoys a high level of biodiversity. In this article an attempt is made to investigate urban sprawl metrics and dynamics in Rasht, Bandar-e-Anzali, and Some-e-Sara in landscape scale using RS data and GIS and also the demographic data collected over the last two decades. The results of the study show that the development of the built-up area was more than the rate of population growth in the area while the proportion of population to the built-up area (alpha density) decreased. The results also suggest that the expanse and pattern of urban sprawl can be determined by utilizing the RS and GIS and the collected temporal and spatial data. Calculating the landscape metrics such as Shannon's entropy, patchiness, and map density, the government's policy of controlling urban sprawl was verified to be effective.