University of Tabriz Water and Soil Science 2008-5133 31 3 2021 09 23 Analysis of Spatiotemporal Variations of Groundwater Drought, Case Study: Karun Watershed Analysis of Spatiotemporal Variations of Groundwater Drought, Case Study: Karun Watershed 101 118 12243 10.22034/ws.2021.12243 FA Samira Zandifar Desert Research Division, Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization (AREEO), Tehran Elham Fijani School of Geology, Faculty of Science, University of Tehran Maryam Naeimi Desert Research Division, Research Institute of Forests and Rangeland, Agricultural Research, Education and Extension Organization (AREEO), Tehran Zohre Ebrahimi Khusfi Department of Nature Engineering , Faculty of Natural Resources, University of Jiroft, Jiroft Journal Article 2019 11 10 Drought as one of the natural disasters has a major impact on parts of an ecosystem. Although it cannot be prevented, its negative effects can be mitigated by some measures. Considering the high importance of groundwater resources in the country, the study of hydrogeological droughts and factors affecting groundwater drawdown is essential for the management of these vital resources. In order to investigate the impact of droughts on each other, the groundwater level variations and evaluation of the groundwater drought in Karun watershed were analyzed using GRI and SDI drought indices over a ten-year statistical period (2008-2018). The results showed a correlation between GRI and SDI indices in most regions of the study areas. Although in some cases, the impact of hydrological drought on groundwater is delayed by 6 months to one year. Low correlation between two hydrological and groundwater drought indices and the high correlation between GRI and groundwater abstraction indicated that drawdown in the aquifers cannot be the sole cause of drought, rather, in some cases, excessive abstraction is more effective. Overall, the GRI indices are more obvious in the southeast and west of the Karun watershed during the ten-year statistical period. In the final years of this period the northern side of the basin has also been affected by more severe droughts, which also has a correlation with the values of the SDI indices. Drought as one of the natural disasters has a major impact on parts of an ecosystem. Although it cannot be prevented, its negative effects can be mitigated by some measures. Considering the high importance of groundwater resources in the country, the study of hydrogeological droughts and factors affecting groundwater drawdown is essential for the management of these vital resources. In order to investigate the impact of droughts on each other, the groundwater level variations and evaluation of the groundwater drought in Karun watershed were analyzed using GRI and SDI drought indices over a ten-year statistical period (2008-2018). The results showed a correlation between GRI and SDI indices in most regions of the study areas. Although in some cases, the impact of hydrological drought on groundwater is delayed by 6 months to one year. Low correlation between two hydrological and groundwater drought indices and the high correlation between GRI and groundwater abstraction indicated that drawdown in the aquifers cannot be the sole cause of drought, rather, in some cases, excessive abstraction is more effective. Overall, the GRI indices are more obvious in the southeast and west of the Karun watershed during the ten-year statistical period. In the final years of this period the northern side of the basin has also been affected by more severe droughts, which also has a correlation with the values of the SDI indices. https://water-soil.tabrizu.ac.ir/article_12243_b81f62742c73347578df977543eb4f16.pdf