Selecting proper sites for underground dam construction using Multi-Attribute Utility Theory in arid and semi-arid regions

Although the construction of underground dams is one of the best methods to conserve water resources in arid and semi-arid regions,applying efficient methods for the selection of suitable sites for subsurface dam construction remains a challenge.Due to the costly and time-consuming methods of site selection for underground dam construction,this study aimed to present a new method using geographic information systems techniques and decision-making processes.The exclusionary criteria including fault,slope,hypsometry,land use,soil,stream,geology,and chemical properties of groundwater were selected for site selection of dam construction and inappropriate regions were omitted by integration and scoring layers in ArcGIS based on the Boolean logic.Finally,appropriate sites were prioritized using the Multi-Attribute Utility Theory.According to the results of the utility coefficient,seven sites were selected as the region for underground dam construction based on all criteria and experts’opinions.The site of Nazarabad dam was the best location for underground dam construction with a utility coefficient of 0.7137 followed by sites of Akhavan with a utility coefficient of 0.4633 and Mirshamsi with a utility coefficient of 0.4083.This study proposed a new approach for the construction of the subsurface dam at the proper site and help managers and decision-makers achieve sustainable water resources with limited facilities and capital and avoid wasting national capital.

Assessment of drought hazard,vulnerability and risk in Iran using GIS techniques

The drought has enormous adverse effects on agriculture,water resources and environment,and causes damages around the world.Drought risk assessment and prioritization of drought management can help decision makers and planners to manage the adverse effects of drought.This paper aims to determine the risk of drought in Iran.At the first stage,standardized precipitation index(SPI)was calculated for the period 1981–2016.Then the probability map of different drought classes or drought hazard probability map were prepared.After that the indicator-based vulnerability assessment method was used to determine the drought vulnerability index.Five indices including climate,topography,waterway density,land use and groundwater resources were chosen as the most critical factors of drought in Iran and followed by the analytical hierarchy process questionnaire,the weights of each index were obtained based on expert opinions.Fuzzy membership maps of each index and sub-index were prepared using ArcGIS software.The drought vulnerability map of Iran was plotted using these weights and maps of each indicator.Finally,the drought risk map of Iran was provided by multiplying drought hazard and vulnerability maps.According to the 43-completed questionnaires by experts,climate index has the highest vulnerability to drought.Climate does not have an important role in drought hazard index,but it is the most crucial factor to classified drought vulnerability index.The results showed that central,northeast,southeast and west parts of Iran are at high risks of drought.There are regions with different risks in Iran due to unusual weather and climatic conditions.We realized that the climate and the groundwater situation is almost the same in the central,east and south parts of Iran,because the land use plays a crucial role in the drought vulnerability and risk in these areas.The drought risk decreases from the center of Iran to the southwest and northwest.