بررسي پايداري اقتصادي و زيست محيطي معيشت عشاير استان فارس با استفاده از منطق فازي

Investigating The Economic and Environmental Sustainability of Nomad Households’ Livelihood in Fars Province Using Fuzzy Logic

در سال­هاي اخير، معيشت عشاير با اختلال­هاي بيروني مانند خشكسالي، تغيير اقليم و تخريب مرتع ­ها رو به رو شده است. از آنجاكه تغييرپذيري ­هاي اقليمي، خدمات بوم سامانه­اي را كه عشاير به آن وابسته هستند تحت فشار قرار مي­دهند، بنابراين براي كمك به عشاير براي حفظ معيشت خود به ابزارهاي كارآمدي نياز است. در اين راستا، چارچوب معيشت پايدار مي­تواند در بررسي زمينه، راهبردها و پيامدهاي معيشتي، مساعدت كند. هدف اين پژوهش بررسي پايداري اقتصادي و زيست ­محيطي ناشي از اتخاذ راهبردهاي معيشتي مختلف در جامعه ­هاي عشايري استان فارس با استفاده از سامانه نتيجه­ گيري فازي (FIS) است. بر مبناي نظرسنجي از 393 خانوار عشايري قشقايي، كه از طريق روش نمونه­ گيري خوشه­اي چند مرحله­ اي گزينش شده ­اند، دامداري سنتي به ­عنوان الگوي معيشت پايه براي عشاير مي­باشد و ارتباط اقتصادي و فرهنگي خود را با عشاير حفظ كرده است. يافته­ هاي پژوهش نشان داد كه شيوه ­ي معيشت مبتني بر دامداري سنتي منجر به وضعيت اقتصادي فقير براي خانوارها و شرايط زيست­محيطي ناپايدار براي مرتع­ هاي طبيعي مي­شود. درحالي­كه كاهش سهم درآمد دامداري و افزايش علوفه مصرفي سرانه، كاهش فقر و بهبود كيفيت مرتع­ ها را به دست مي­آورد. نتايج مدل فازي طراحي شده گوياي اين است كه دستيابي به پايداري اقتصادي و زيست­محيطي مشروط به تركيب درست و بهينه دارايي­ هاي معيشتي است.

Introduction The nomads’ main livelihood is based on traditional pastoralism activities in the Middle East and North Africa, 34% of the total lands in those areas are natural rangelands. However, about 61% of rangelands in the Middle East and North Africa are of medium to low quality. While traditional pastoral activities have positive effects on nomadic livelihoods and livestock, natural rangelands and natural resource-based livelihoods are under pressure due to external disturbances such as climate change. Sensitivity of traditional pastoral systems to climate diversity and change has increased through human activities. Excessive dependence of nomadic households on natural rangelands and their unsustainable exploitation due to overgrazing has led to significant destruction of these natural resources and the spread of desertification in arid and semi-arid regions. To increase the resilience of nomads exposed to climate and non-climate risks, targeted programs and policies need to be formulated using the concepts of assets, strategy, and livelihood outcomes. Despite several studies on livelihood vulnerability to climate change and sustainable livelihood frameworks in developing countries, most studies have focused on farming households and information on nomadic livelihoods is not enough in developing countries. In addition, studies on the livelihood strategies of nomads under climatic and non-climatic risks are low or insufficient. Without accurate information, it is very difficult to improve the welfare of nomads and their resilience to climatic and non-climatic risks. Some research examines livelihood strategies and their effects on household resilience however, it is not yet clear to what extent expectations of economic and environmental sustainability are met through livelihood strategies. In this regard, this study was aimed to determine the effects of assets and livelihood strategies on the economic status of nomads and rangeland environmental conditions. Materials and Methods To evaluate economic and environmental sustainability based on assets and livelihood tree algorithm. Subsequently, these rules were fuzzy and used in the fuzzy inference system (FIS). It should be noted that the input and output variables of the Mamdani-based fuzzy inference system must be continuous, or discontinuous variables that have sequential values. Thus, the sequential values of these continuous and discontinuous variables can be converted to fuzzy linguistic values. In this study, the livelihood strategy variable is a discontinuous variable that has non-sequential values (nominal variable). Therefore, to consider the variable of livelihood strategies in the fuzzy inference system, two alternative continuous variables were used, including the share of livestock in total income and per capita forage consumption. Other input variables of the FIS include three human, natural, and physical assets. Fuzzy logic can predict the economic status of nomads and the environmental conditions of their rangelands as model outputs based on specific inputs, including household assets and livelihood strategies (replaced by the share of livestock in total income and per capita forage consumption). The fuzzy inference system executes most of the model inputs and outputs by four units, including fuzzification, fuzzy rules, inference engine, and defuzzification. Linguistic values have been used to fuzzy the input and output variables of the FIS. Both triangular and trapezoidal membership functions have been used to construct membership functions. Fuzzy logic can combine all the basic linguistic rules for a fuzzy model. Results and discussion At the beginning, the appropriate rules extracted from the decision tree model are used in the FIS. Out of a total of 25 rules obtained, 14 rules are related to economic status and 11 rules are related to environmental conditions. In front of each rule, two criteria of confidence and support are given. As an example, rule number one is 100% confident and is supported by six sample households. The maximum and minimum confidence criteria for the extracted rules were 100% and 35%, respectively. Also, their maximum and minimum support criteria were 125 and six households, respectively. For example, rule number one indicates that if 0.14