Department of Minerals and Groundwater Resources, School of Earth Sciences, Shahid Beheshti University, Tehran, Iran.
GIS and Remote Sensing Studies Center, School of Earth Sciences, Shahid Beheshti University, Tehran, Iran.
Environ Monit Assess. 2021 Mar 12;193(4):182. doi: 10.1007/s10661-021-08955-w.
Several studies have evaluated the impact of climate change on the alluvial aquifers; however, no research has been carried out on a small-scale aquifer without any human influences and pumping wells. The object of this study is to assess the response of such an aquifer to the climate change to observe if it can preserve its storage or not. Pali aquifer, southwest Iran, is solely discharged by Taraz-Harkesh stream and geological formations. On the other hand, it is recharged by precipitation and geological formations. The Taraz-Harkesh stream's discharge rates and the Pali aquifer's groundwater level were simulated by IHACRES and MODFLOW, respectively, in the base (1961-1990) and future (2021-2050) time periods under two Representative Concentration Pathways, i.e., RCP4.5 and RCP8.5. The outputs of IHACRES were regarded as the input of MODFLOW. The groundwater model was calibrated in the steady-state for the hydrological year 2007 and in the unsteady-state for the time period 2008-2014 with annual time steps. Further, the groundwater model was verified for the time period 2015-2018. The statistical criteria maintained the groundwater model's ability, consequently measuring the root mean square error to be 0.69, 0.85, and 1.18 m for the steady calibration, unsteady calibration and verification of the groundwater model, respectively. Results indicate that the stream's discharge rates would decrease in the future time period, especially under RCP8.5. Nevertheless, the groundwater level would not fluctuate considerably. Indeed, the groundwater resources, even a semi-arid, small-scaled aquifer, may be considered as the water supplying systems under the future climate change.
已有多项研究评估了气候变化对冲积含水层的影响，但针对无人类影响和抽水井的小型含水层，尚无相关研究。本研究旨在评估此类含水层对气候变化的响应，以观察其是否能够保持储水能力。伊朗西南部的帕利含水层仅由塔拉斯-哈克什溪流和地质构造排泄，同时也通过降水和地质构造补给。利用 IHACRES 和 MODFLOW 分别模拟了塔拉斯-哈克什溪流的流量和帕利含水层的地下水位，这两个模型的输入数据是在两种代表性浓度途径（RCP4.5 和 RCP8.5）下的基础期（1961-1990 年）和未来期（2021-2050 年）。IHACRES 的输出结果被用作 MODFLOW 的输入。地下水模型在稳定状态下，针对 2007 年水文年进行了校准，并在非稳定状态下，针对 2008-2014 年的时间段，使用年度时间步长进行了校准。此外，还对 2015-2018 年的时间段进行了验证。统计标准保持了地下水模型的能力，因此，稳定校准、非稳定校准和地下水模型验证的均方根误差分别为 0.69、0.85 和 1.18m。结果表明，未来时期溪流的流量将减少，特别是在 RCP8.5 下。然而，地下水位不会出现大幅波动。事实上，即使在半干旱地区，小型含水层的地下水资源也可以被视为未来气候变化下的供水系统。
