Spatial Analysis of Environmental Hazards

Spatial Analysis of Environmental Hazards

Site selection of crisis management base in Kahrizak District of Ray County

Authors
farhad azizpour
Vahid Riahi
Ali Moazeni
university of kharazmi
Abstract
Environmental hazards are considered as one of the main obstacles for achieving sustainable human settlements development (particularly in rural areas). Today, with a new look at crisis management, using all managerial, organizational and planning accomplishments before the crisis, is an essential and rational concern. Rural settlements of the country along with cities always are threatened by a variety of environmental hazards, but what makes these spaces different from the cities is the high-intensity of vulnerability due to its physical decay texture. In this regard, one of the key elements in confronting the possible crisis that must be taken into account is the crisis management bases in which all prevention, preparedness and response measures, including disaster relief, temporary accommodation for the injured, etc. is provided and minimizes the consequences of potential crisis. Being located in the Kahrizak fault zone and the placement of hazardous industries in this region, is the main reason for selecting Kahrizak district as a study area in this research. To achieve goals of constructing crisis management bases which indeed is the tactic ability of crisis management system (CMS), it is required to set the site selection criteria and standards for constructing them in such a way that provide more operational activities and develop the level of their impacts. In this regard, in the first step, the final criteria for site selection of crisis management base were selected after reviewing previous studies. Then, after surveying the experts and also the localization of criteria on the basis of area condition, seventeen final criteria were determined. For quantitative criteria, data were collected through organizations and reference centers and for a single qualitative criterion (cultural convergence), the questionnaire instrument used in gathering data. After collecting data using library and field methods, a combination of two models: fuzzy logic and hierarchical analysis process (AHP) applied for optimal location of crisis management base. To determine the impact level of each criterion in the site selection process in two above-mentioned models, the standards for each of the seventeen criteria was determined with the help of combination method. The standards of some of the criteria determined using the standards in related organizations and some other standards proposed by experts and also through the localization by the researcher. Afterward, initially fuzzy standardized common scale maps produced from all information layers in a raster format. Then selected criteria by experts in the format of AHP model were compared with each other through pairwise comparison method. As a result of this comparison, the weight of criteria was determined which indicates the preference degree of each criterion over the others. At last, all standardized (fuzzified) layers multiplied in each of the final weight resulting from Analytical Hierarchy Model and in total converted into weighted fuzzy layers. In the next step, following the process of fuzzy model, fuzzy addition and multiplication operators were applied on output layers. Finally, to modify the layer resulting from fuzzy addition and multiplication, the Gamma operator was used. As such, after producing layers of different fuzzy gammas, essential assessment was conducted for selecting appropriate and ideal gamma. In order to do this, produced layers of each fuzzy gammas were compared with the study area for optimal location and the establishment of crisis management base. Since the gamma 0.9 had the most conformity to suitable zone in the layers of study area, it was selected as the appropriate gamma. However, to ensure the selected location, field study was conducted. According to the research findings, the following conclusions were obtained: Site selection criteria for rural crisis management base not only has an environmental essence (built and natural), but socio –economic criteria are important as well Effective criteria for site selection of rural crisis management base, affected by regional and local requirements are not the same. Localization of criteria is a necessity that should be considered in site selection. Standards based on site selection criteria depending on the type of services, goals and location at multiple spatial levels (regional, local, urban and rural) is different: in the other words one size does not fit all Site selection is not only based on the location within overlaying information layers by using the models, but the final choice is done after field evaluation and visit.
Keywords
Site selection
crisis management base
Fuzzy logic
AHP
GIS
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