Department of Water Engineering and Management, Tarbiat Modares University, Tehran, Iran.
Department of Hydrology, Meteorology and Water Management, Institute of Environmental Engineering, Warsaw University of Life Sciences, Warsaw, Poland.
Sci Total Environ. 2022 Jul 15;830:154810. doi: 10.1016/j.scitotenv.2022.154810. Epub 2022 Mar 24.
Agricultural activities in the concept of integrated water resources management play a vital role. Especially in dry and semi-dry regions, agricultural activities have the largest share of water consumption. By employing a model-based approach using modified Soil and Water Assessment Tool (SWAT agro-hydrological model), this study has prepared Water Accounting Plus (WA+) framework requirements to investigate different conditions of supply and demand in wet (1985-2000) and dry (2001-2015) periods in a semi-dry basin (Karkheh River Basin) in Iran. Our assessments based on WA+ show decreasing 10% (21.65 to 19.29 Billion Cubic Meters (BCM)/year) of precipitation in the dry period caused a 4% (0.13 BCM/year) decline in natural evapotranspiration. However, the basin experienced a 24% increment in evapotranspiration from agricultural activities at the same period, and runoff was approximately halved (2.45 BCM/year). Therefore, especially in downstream parts, surface water withdrawal has decreased by 18%. These new conditions have put pressure on groundwater resources. The aquifer extraction and total withdrawal for irrigation have grown by about 17% and 4%, respectively. Finally, it is evident that the manageable water has diminished due to climate change; not only the managed water consumption in the basin has not reduced, but it has also highly risen. The current study results help water authorities arrange new hydrological and climatic conditions strategies.
在水资源综合管理的概念中，农业活动起着至关重要的作用。特别是在干旱和半干旱地区，农业活动的用水量最大。本研究采用基于模型的方法，使用改进的土壤和水评估工具（SWAT 水文学模型），为水会计加（WA+）框架需求制定了准备工作，以调查半干旱流域（伊朗卡伦河流域）湿润期（1985-2000 年）和干旱期（2001-2015 年）不同供需条件。我们基于 WA+的评估显示，干旱期降水量减少 10%（从 216.5 亿立方米减少到 192.9 亿立方米/年）导致自然蒸散量减少 4%（0.13 亿立方米/年）。然而，同期农业活动的蒸散量增加了 24%，径流量减少了近一半（24.5 亿立方米/年）。因此，特别是在下游地区，地表水的开采量减少了 18%。这些新情况给地下水资源带来了压力。含水层抽取和灌溉总取水量分别增长了约 17%和 4%。最后，很明显，由于气候变化，可管理的水量已经减少；流域的管理用水量不仅没有减少，反而大幅增加。本研究结果有助于水资源管理部门制定新的水文和气候条件战略。
