Multi criteria decision making application for site selection of artemia farming in arid region using saline water resources (Case study: SiahKouh Playa, Yazd)

The major threat to habitability may be the degradation of arid lands in developing countries where many people depend upon restricted resources for their livelihood. Although land degradation process in arid regions (desertification) is not new or site specific، the environmental awareness in a world board scale has extended and generated a wider public interest، extensive to the scientific circles and governments. Desertification affects the livelihoods of millions of people، including a considerable proportion of the poor in arid lands which occupies about 41% of the Earth''s land and are home to more than two billion people. The persistence of unresolved stabilization of these fragile environments and the substantial decrease in the provision of ecosystem services as a result of intensive use of resources، incapacity of wide spread suitable technologies for providing rose supply of food، forage and fuel، water scarcity، and climate change puts desertification in among the main environmental challenges today and a major impediment to getting human needs. Recently، arid regions and desert ecosystems with including several potential and various resources such as unconventional water became remarkable area for economic projects. Regarding to desert condition and in order to guarantee both rich and sustainability and prevent undesirable consequences of these economic projects، addressing the suitable areas for aquaculture is very vital consideration in any aquaculture activities. Relatively rarely، in the case of suitable site selection research، the researchers apply Geographical Information Systems (GIS) based MultiCriteria Evaluation (MCE) analysis to determine suitable sites in aquaculture in Iran. Therefore، this study was conducted to identify suitable sites for Artemia farming development in SiahKouh Playa، Yazd using Multi Criteria Decision Making (MCDM). The method is based on Analytical Hierarchy Process (AHP) which is one of the multi-criteria decision making methods. Analytical Hierarchy Process usually includes three phase: first، the decomposition of a complex problem into a decision hierarchy in order to determine the main components of the problem، second the evaluation of options (comparative judgment) by means of a pairwise comparison، which enables the decision maker to assess the contribution of each criterion to the overall goal، and finally third the synthesis of the priorities، so as to identify the relative preferences for the chosen policy options. One of the major advantages of this method is that it considers the interrelations between different levels of decision as well as the interconnection of the decisions in one level. Following determining the decision makers group، the most important criteria effective in determination of suitable area in study area were identified through comparison questionnaires filled by the experts and researchers. The second questionnaire was designed to determine the rate of each criterion to choose the best alternative. The thematic layers of slope، geology، geomorphology، soil، vegetation، climate such as isohyet، hydrometery، land use، power lines and management quality indices are the main data required for determining the suitable area for Artemia farming. These layers were extracted and manipulated from the available topographic، geologic maps، aerial photographs and field survey data analyses. Spatial analyst function in Arc-GIS 9. 2 software was used for matching the thematic layers and evaluating the aquaculture indices. The results showed that three main factors are effective in suitable area determination for aquaculture units in desert ecosystem. These factors are as follow according to their importance، environmental، technical، and infrastructure، socio-economic. The environmental criteria were included geomorphological faces and rangeland area. The indices in the technical criteria were slope percentage، soil texture، unconventional water resources and climatology factors such as evaporation، rainfall and temperature. The indices in the infrastructure، socio-economic criteria were based on distance to cities، roads and power sources and also land use. Finally those criteria and indices were applied to address the optimal areas for Artemia farming by using weighted linear combination assessment. In the final result of this study، suitability levels were determined as suitable area (area with high potential، located east and eastern south of study area) and non suitable area. The results of this study indicated that the best choice among three alternatives is considering the geomorphological faces as assessing and monitoring unit of other criteria in arid and desert ecosystems. Also، using multi criteria analysis methods will help to make better decision and choose effective alternatives.