Locating Suitable Directions for Kamyaran Urban Development through a Hazardology Approach based on the Application of Geomorphologically Restricted Areas

The location of Settlements and other facilities created by humans is fully influenced by environmental factors, especially Geomorphology and Geology. Establishment and growth of cities, irrespective of the capabilities of the land and its talents, have many destructive and harmful effects, and increase the multiplicity of financial and mortal damages in times of crisis. From the hazardology and management point of view, most of the damages are related to the incorrect placement of buildings and structures. Therefore, the importance and necessity of recognizing the characteristics of natural environments to identify the appropriate points for the construction of buildings, is very noticeable. 
In this way, through the study of Geomorphology, effective steps can be taken to select the most appropriate location for the expansion of cities and take serious action to prevent or counteract with risk of natural phenomena.

The present research is based on a managerial and hazardology approach, aiming locating the areas susceptible to urban development using the forbidden areas method. For this purpose, to provide a theoretical framework, the existing literature have been reviewed. Then, along with the application of specific methods in the field of software, expert discussions were used. To select the areas prudent for the desired purposes, eight criteria and effective environmental parameters including elevation, slope, aspect, distance from the river, land use, lithology, distance from the fault and urban areas and their layers were provided. Then, according to the existing standards and experts’ opinions, the forbidden areas were identified. Other areas of study outside of the forbidden areas were identified as suitable zoned for future urban development. In doing so, the Fuzzy logic and ANP models, the value of each layer was calculated. Fuzzy Gamma operator has been used to modulate the high sensitivity of the Fuzzy operator. Finally, overlapping the layers, map which entails both forbidden areas and those susceptible for urban development, was created.

 In the first stage, the effective environmental parameters in the survey of the favorable areas of urban development of Kamyaran, include Geological parameters (Lithology and Fault), Geomorphological parameters (Slope, Aspect, Elevation), Hydrogeomorphological parameters (River) and, finally, Human parameters (Land use and Distance from Urban areas) as effective information layers were considered.  Then the layers were Fuzzy and the banned areas were determined. Investigating the parameters in the study area showed that in terms of lithology, most of the study areas is covered by Quaternary Sediments. The Location of urban areas in different parts of the city is not significantly different. However, there are several fault lines in the northeastern range that limits the city's expansion in this direction. In terms of topographic parameters, apart from the northeastern mountainous masses with a height of more than 1800 meters and a slope of more than 30 percent, there are no special restrictions on other parts of the area. The surface water currents of the area are drained by the slope of the south and southwest of the area. Therefore, in relation to the risks such as urban flood and due to tissues of sediment of the area, respecting the buffer is essential that in this study, 200 meters of the river was estimated. According to the study of environmental variables and the application of prohibited areas, it can be concluded that suitable zones are mainly located at a close distance from the current urban areas. They all have low Slope, low Elevation, south Aspect and proper distance from the rivers and fault lines.

The findings of this research show that the area of research is 166 square kilometers. 37 percent, equivalent to 4.61 square kilometers of study area, were among the forbidden areas. In terms of Neotectonic, Lithological, Topographic and Hydromorphological parameters, it is in some way at risk. This range is often found in the northeastern part of the study area. Since the current area of the city is about 5 square kilometers, it can be concluded that the city has the optimal development space for several years on low-risk route. Therefore, it can be said that existing research based on the application of prohibited areas and system approach is the basis for efficient spatial management of urban and around cities development.