Determination of long-term water resources strategy in arid zone (Case study: Shahrood township)

In recent years, water supply systems for municipal, industrial and agricultural uses have been faced with critical conditions (especially in arid regions) under the influence of human activities and his economic development and industrialization. This affects quality of life of communities particularly societies in arid regions, so the planning and management of water resources has become essential to improve the quality of life of communities. Sustainable watershed management requires collaboration of specialists in social sciences, natural sciences, water resource managers, planners and politicians. The complexities of evaluation indicators in water resources management and also the conflicts of interest between the farmers, other stockholders and policy-makers are among the reasons that necessitated the use of Multi-Criteria Decision Making (MCDM) methods for water resources planning. Numerous applications of MCDM methods have shown that they are useful tools in decision-making for water resources planning and management. The best evaluation criteria to achieve the prospect of sustainable development are indicators of sustainable development. Thus, the most appropriate prioritization to implement strategies can be obtained by evaluating sustainability of strategies with regard to sustainable development criteria. Literature review shows that the application of MCDM methods in water resources management can provide acceptable results for water resources planning. In most previous studies, the use of MCDM methods in water resources management has been in levels of reservoir management or farm management. In this study, the MCDM methods have been used for prioritizing water resource management strategies in different parts of a dry area. Thus, we addressed it in this research to provide an appropriate model to involve sustainable development criteria in choosing the best sustainable water resources management strategy for an arid region in central desert of Iran.
The Shahrood Township is one of the eight cities in the Semnan Province. This Township is located in the north eastern part of Iran, in the north part of a desert and southern slopes of the Alborz Mountains. The hydrological and meteorological records of the Semnan Province shows that this region has cold and dry climate based on the Domarten index. The rivers that flow in this area are not permanent. Most of these rivers are mountainous with low water which only in times of high rainfall cause floods and flow to the Kavir plain. This region which is one of the arid regions of Iran is faced with water shortage, and so the strategic management of water resources based on sustainable development can improve future water resources management in this region.
In this study, to determine the long-term strategy for water resources management in the region, a hybrid of brain storming with MCDM methods of Simple Additive Weighting (SAW) and Analytic Hierarchy Process (AHP) were used. In the brain storming session sufficient information was notified to meeting members with a description of the problem and objectives and then the opinions and ideas were produced and finally the best of them were selected. Using this method nine (9) different water resources management strategies in the Semnan province were obtained for the assessment by the MCDM models. Sustainable development criteria used in this study were obtained from previous water resources studies. These criteria were weighted at the meeting of experts. The results of the surveys have uncertainty due to the uncertain, imprecise and not defined elements in the judgments. In order to reduce errors arise from this uncertainty, the sensitivity analysis were performed on the results for ±20% changes in criteria weights.
The results showed that the strategy of the “study and implementation of spatial planning” in SAW model and the strategy of “supervision of aquifer pumping” in AHP are top-ranked.
The minimum acceptable score for each strategy in order to satisfy the sustainable development was determined as 50% of weights, and this was not observed by “inter-basin water transfer strategy” in application of AHP model. So this strategy is not suggested for implementation.
In addition, sensitivity analysis showed that the SAW and AHP models were more sensitive to changing “Socio-cultural acceptability” and “Environmental conservation” criteria weights that have high weights among other criteria. The AHP model is less sensitive than SAW model with regard to criteria’s weights but its ranking is almost similar to SAW model. Therefore, determination of long-term strategy for water resources management is recommended by AHP model.