GroMoPo Metadata for Isfahan-Borkhar aquifer MODFLOW model

Recently, many studies have investigated the effect of climate change on groundwater resources in semiarid and arid areas and have shown adverse effects on groundwater recharge and water level. However, only a few studies have shown suitable strategies for reducing these adverse effects. In this study, climate conditions were predicted for the future period of 2020-2044, under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5, for Isfahan-Borkhar aquifer, Isfahan, Iran, using MODFLOW-2000 (MODFLOW is United States Geological Survey product). Results showed that the average groundwater level of the aquifer would decrease to 13, 15, and 16 m in 2012 to 2044 approximately under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. Then, three groundwater sustainability management scenarios were defined that included 10%, 30%, and 50% reduction in groundwater extraction. These strategies simulated the reduced negative effects of climate change on the aquifer. The results showed that decreases in water withdrawal rates of 10%, 30%, and 50% under RCP8.5 scenario (critical scenario) could decrease the mean groundwater level by 14, 11, and 7 m, respectively. The main result of the study showed that 50% reduction in groundwater withdrawal may increase the groundwater levels significantly in order to restore the aquifer sustainability in the study area. In this study, with assuming that the current harvest of wells in the future period is constant, so the results of studies showed that for the aquifer's sustainability management, the water abstraction from the aquifer should reduce up to 50% of the existing wells. Changing the irrigation method from surface to subdroplet irrigation plays an important role in reducing the withdrawal from the aquifer. The results of a study in Iran have shown that the change in the irrigation method from surface to subdroplet irrigation causes a 40% reduction in water use for agriculture.

近期，众多研究已对气候变化对半干旱和干旱地区地下水资源的效应进行了探讨，并揭示了其对地下水补给和水位的负面影响。然而，仅有少数研究提出了减轻这些负面影响的适宜策略。在本研究中，利用MODFLOW-2000（MODFLOW为美国地质调查局的产品）对伊朗伊斯法罕-博尔卡赫含水层进行了2020-2044年未来期内的气候条件预测，预测情景包括RCP2.6、RCP4.5和RCP8.5。结果显示，在RCP2.6、RCP4.5和RCP8.5情景下，该含水层的平均地下水位分别预计将在2012至2044年期间下降至13米、15米和16米。随后，定义了三种地下水可持续管理情景，包括地下水开采量减少10%、30%和50%。这些策略模拟了气候变化对含水层负面的减少效应。结果显示，在RCP8.5情景（关键情景）下，将取水率分别降低10%、30%和50%可以分别使平均地下水位降低14米、11米和7米。本研究的主要结果表明，将地下水取水量减少50%可能显著提高地下水水平，以恢复研究区含水层的可持续性。在本研究中，假设未来期内井的采水量保持恒定，因此研究结果指出，为了实现含水层的可持续管理，从含水层中提取的水量应减少至现有井口50%。将灌溉方式从地表灌溉转变为微滴灌溉在减少含水层取水方面发挥着重要作用。伊朗的一项研究表明，将灌溉方式从地表灌溉转变为微滴灌溉导致农业用水量减少了40%。