Currently, adaptation to water resources changes is one of the priorities in integrated water resources management. The capability of learning from past experiences is one of the main characteristics of such an adaptive structure which is crucial in dealing with changes. Adopting a social learning framework, this study aims to assess the water institution (both formal and informal) in the Tashk-Bakhtegan Basin. The social learning loops, orientation and direction features were adopted to assess the formal institution. To assess the informal institution, the drought of 2008 was considered as the change that affected the water resources system of Tashk-Bakhtegan Basin. The responses of informal water institution to that change were then assessed. Formal institutions were assessed by using qualitative content analysis of water law and project's documents. Informal institutions were detected by using snowball sampling and were assessed by using semi-structured interview and qualitative content analysis. For formal institutions, the results showed that this structure relies on the national authorities and has low level of learning capacity. In the informal sector, the components of social learning process were generally found low in the upstream (because there is still enough water resources), but those components were found at much better levels in the downstream. The assessment of social learning outputs components showed that the downstream sub-regions were at a higher level of social learning capacity comparing with the upstream (double and triple loops of learning are active), and the responses were oriented towards better conservation of water resources. Furthermore, the width of those responses went beyond individual levels to collective and participating levels. Therefore, those sub-regions showed to have higher level of adaptation capacity. For the water institution of the Tashk-Bakhtegan Basin, this paper suggests that implied mechanisms of water laws need to be modified, national and centralized governance requires to be transformed to participatory and cooperative structures, private and public institutions need to be initiated, and finally the components of social learning process, that were found at a low level, require to be improved.

In the present era, Climate change and its impact on available water resources are one of the main challenges. In this regard, temporal and spatial analysis of temperature and precipitation, which are important parameters in determining the status of water resources, can be used to assess the hydro-climatological conditions of the watershed and appropriate management policies. In this research, the trend in precipitation and temperature distribution over 30 years testing period of 1981-2010 was investigated using non-parametric tests such as Man-Kendal, Spearman, Sen’, s Slope, and Pettit. Afterward, interpolation techniques, such as IDW, LPI, GPI, and RBF were used to detect spatially trends at the watershed. The results showed that precipitation decreased by 14. 3% during the period 1981-2010 and the temperature increased by 3. 5%, with changes in precipitation and temperature occurring in 2004 and 1985, respectively. However, the negative trend in precipitation was not significant in contrast to the positive temperature trend during the study period. A comparative analysis of interpolation techniques shows that Ordinary Kriging and Radial Basis Functions with least error are the best methods for spatial analysis of precipitation and temperature, respectively.

Water scarcity is one of the most important and influential factors in the pattern of crop cultivation and farmers' profits. This research was conducted to evaluate the effects of rainfall reduction on cultivation pattern and farmers' profits in the Tashk-Bakhtegan basin. To this purpose, a composed model which includes two parts, hydrological and economic was used. In the hydrological section, the water evaluation and planning system model (WEAP) and in the economic section, the positive mathematical planning model (PMP) were used. In this research, the effects of rainfall reduction at two scenarios of 20 and 40% reduction on the agricultural sector are determined by determining the amount of water delivered to this sector and then the reaction of farmers is examined through their cultivation pattern and profits. This modeling was done regionally in 5 separate zones of the Tashk-Bakhtegan basin and compared to the base year (2006-2007). The results of this research showed that with the implementation of the scenario of 20% rainfall reduction, the area under cultivation and farmers 'profits decreased by 33 and 29%, respectively, and at the scenario of 40% rainfall reduction, the amount of the cultivation area and farmers' profits decreased by 36 and 32%, respectively. Among the different crops, the most changes in the area under cultivation were related to alfalfa and the area under cultivation of rice did not changed due to its high profits.

Water resources systems are facing with changes in terms of natural and socio-economic aspects. As a result, water resources management should be prepared for the future possibilities, rather than relying on the predicting of probabilities. Hence, the management approach should tend towards the mechanisms which can promote understanding and adapting to changes. That school of thoughts which is based on versatility with changes is known as adaptive management. From this perspective, adaptation to change is a priority for the adaptive management. One of the main features of an adaptive structure, is its capacity to adapt to change. Thus, this study aims to assess the adaptive capacity of the local organizations in Tashk– Bkhtgan Basin versus water scarcity. The adopted methodology is based on the Adaptive Capacity Wheel. The required data were gathered using questionnaires and structured interviews. The results show that a relatively negative adaptive capacity within the local organizations. That means there are gaps among the local organizations to deal with the negative effects of new conditions that need to be repaired.

To develop appropriate management strategies and solve water issues, the analysis of water resources systems requires different information to provide a deep and proper understanding of the hydrological processes of the basin, manageable and unmanageable water flows, and interactions with land use and provide a comprehensive picture on this issue. In this regard, by integrating various structural information for a comprehensive integrated management of water resources and applying targeted policies, water accounting framework is consciously provided as a useful tool. The aim of this paper is to provide an application of Water Accounting Plus (WA + ) Framework in the Tashk-Bakhtegan basin based on modification of the Soil Water Assessment Tool (SWAT) model. In this study, it has been provided an analysis of basin conditions in three time periods based on Water Accounting Plus (WA +). The analysis of the results indicates that the Tashk-Bakhtegan basin is a closed basin. In this basin, due to climate change, the manageable water resources have been remarkably declined and unfortunately, not only water managed consumption in the basin (Supplementary Evapotranspiration) have not been reduced but also it has been considerably increased (53%). This has led to a decrease in outflows as the water right supplier of the lake. Moreover, the results indicate an increase in groundwater resources deficiencies and their unsustainable exploitation. Increasing transpiration of plants in agricultural land is another factor influencing the current situation of the Tashk-Bakhtegan basin, due to the expansion of the land area and the increase of high water consuming plants as well as significant contribution of the soil evaporation of the total nonbeneficial consumption of the basin. At the other hand, a significant amount of agriculture water withdrawal is returned to the water basin cycle which emphasizes on "depletion "to "withdrawal" planning.

Introduction Food security is a multi-dimensional phenomenon that occurs when all people have physical, economic, and social access to sufficient and safe food for an active and healthy life at any time. On the other hand, food insecurity imposes a significant burden on society through healthcare and social costs. The achievement of food security is one of the most important national and international development concerns. Hence, one of the most important ways to improve food security is to pay special attention to the agricultural sector. However, this sector is the most vulnerable to the consequences of climate change, which ranks first among the ten most dangerous human phenomena. Therefore, it is essential to adopt appropriate strategies to mitigate the effects of climate change on food insecurity. Materials and Methods In this paper, the impact of adopting climate change adaptation strategies on food security was studied using the Propensity Score Matching (PSM) approach. Factors influencing the adoption of climate change adaptation strategies were studied using a multi-variable probit model in Bakhtegan-Tashk basin. A total of 300 farmers were selected using a multi-stage sampling method in the Bakhtegan-Tashk basin. Results and Discussion The results of the Propensity Score Matching (PSM) approach showed that if farmers adopt climate change adaptation strategies such as diversification of livelihood activities, modern irrigation systems, construction of irrigation ponds, and use of low-water-need varieties, the household calorie intake of the sample households would increase by approximately 219.85, 182, 137.82, and 83.23 calories, respectively. Furthermore, the results of the multi-variable Probit model showed that the age of the farmer, education level, household size, household income, access to credit, irrigation water supply, ownership of agricultural machinery, access to agricultural extension services, number of crops planted, and soil quality are considered significant determinants of adaptive strategies. Conclusions According to the results, the most important solution to mitigate the negative consequences of climate change on food insecurity is to adopt the diversification of livelihood activities. It is therefore recommended that the research results, especially the effects of adopting adaptive strategies to climate change on food security, be taken into account in the formulation of national food security programs.

Water resources carrying capacity (WRCC) is a major component of resource and environmental studies and it is a management concept aimed at supporting sustainable socioeconomic development on a regional scale and catchment areas. Failure to pay attention to concepts such as the carrying capacity in the country's planning has led to the ineffectiveness of most programs. For this purpose, in the present study, it has been tried to use the simulation-optimization approach to determine the water resources carrying capacity in a pilot basin (Tashk-Bakhtegan Basin), considering the economic, environmental and Water resources in the historical periods (1985-2014) and terms of climate change (2045-2015) should be considered. In this regard, the Water and Soil Assessment Tool (SWAT) and the Genetic Algorithm are used. For this purpose, the outputs of three general circulation atmosphere models under RCP 2.6, 4.5, 8.5 scenarios have been used to assess climate change in this study. The results of the study indicate overloading of water resources due to increased crop area in all studied periods. Also, the water resources carrying capacity due to climate fluctuations and climate change in the examined period (1985 - 2045) has been declining, and from 2.6 billion cubic meters in the period (1985-2006) to 1.9 billion cubic meters. The most pessimistic climatic conditions are reduced.