Geomorphological analysis of constraints on the physical development of the city by emphasizing the Gully (Case Study: Mohr City in the southern province of Fars)

Rapid population growth and physical expansion are the main problems of cities in the developing countries. It is necessary to recognition and analysis of land properties and it’s suitability in addition to socio-economic analysis for appropriate control of physical development and urban sprawl. The aim of this study is analysis of gully erosion phenomena and its effect on the physical development of Mohr city in the southern of Fars province. According to this, the goal this study is recognition of phenomena and geomorphological process effect on the physical development of city with an emphasize on gully erosion and its limitation. The materials used in this study consist of topographic maps (scale 1:25000), geology, land use data and aerial photos of the years 1957, 1995 and 2014. After preparing all of the data, AHP method has been used for zoning of gully hazard erosion in the study area. The result shows that physical development of Mohr city is face to the geomorphological limitation in all direction. But the processes of gully erosion and slope are the main limitations of urban development. It seems that the most of these constraints are in the north, northwest, northeast and south of Mohr city. Also, the results of gully erosion zoning show that lithology, land use, distance from the streams, slope and distance from the roads have the most value respectively in gully erosion and the Mohr City is in the high and very high zones. Engineering methods for controlling streams in short term and watershed management for controlling runoff in long term and management program for soil modification are the main approaches to preventing gully erosion increasing in Mohr city.