Document Type : Research Paper

Authors

• Zahra Saiedifar ¹
• Mohammad Rahimi ²
• Sakineh Lotfinasabasl ³
• Mohammad Khosroshahi ⁴
• Mohammadreza Yazdani ²

¹ Ph.D. Student in Combating Desertification, Faculty of Desert Studies, Semnan University, Iran

² Associate Professor, Faculty of Desert Studies, Semnan University, Iran

³ Email: "mrahimi@semnan.ac.ir". 3- Assistant Professor, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.

⁴ Associate Professor, Desert Research Division, Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

Abstract

    Jazmurian basin in the southeast of Iran is one of the most important and vital basins. Due to the lack of surface water resources and placing in the priority of use this basin is faced with a sharp decline in the level of underground aquifers.TheThe aim of this study was to identify the factors affecting groundwater resources and predict the groundwater level and its variation in Jazmourian Basin. In this study by considering the importance of identifying the factors affecting the condition of groundwater resources and the causes of decline, initially, the geological and geomorphological features of the basin and its impacts on the quantity and distribution of the groundwater resources were studied. Then, the effect of hydrological droughts with using two streamflow index (SDI) and the standardized precipitation index (SPI) at hydrometric, pluviometric, and synoptic stations located in the basin aquifers was studied. The portion of perceptions on changes in groundwater resources by wells, spring, and aqueducts, as well as the impact of surface structures and expenditures on land surface level changes were determined. In addition, the average monthly and annual mean of groundwater levels during the years 1370-93 were investigated using time series models to predict groundwater changes by the year 1420. The study results on the effect of different factors on groundwater water changes showed that hydroclimatic droughts, although affecting underground water changes, did not have a significant effect. The dams and deep and semi-deep wells with negative correlations of 0.83, 0.75 and 0.68 had the most negative effects on groundwater drops, respectively, and the average discharge of wells and springs increased significantly with increasing groundwater level. Also, the study of changes in groundwater level in the basin indicates a significant decrease (0.37 m / year) and predictions show that in the coming years it will face more severe losses. The high level of decline was observed in the summer with a change of 1.96% and in the autumn it was 1.78% lower than the other seasons. Overall, the results showed that if the current trend of exploitation of the groundwater resources continues, the region will be facing more challenges.

Keywords

• Groundwater level drop
• time series model
• hydroclimatic index
• utilization