Reta Birara Gebeyhu, Hatiye Samuel Dagalo, Finsa Mekuanent Muluneh
Faculty of Water Resources and Irrigation Engineering, Arba Minch Water Technology Institute, Arba Minch University, Arba Minch, Ethiopia.
Water Resources Research Centre, Arba Minch Water Technology Institute, Arba Minch University, Arba Minch, Ethiopia.
Heliyon. 2024 May 16;10(10):e31332. doi: 10.1016/j.heliyon.2024.e31332. eCollection 2024 May 30.
Crop water requirement and irrigation scheduling in Lower Kulfo Catchment of southern Ethiopia have not assessed under climate change scenarios, and the allocation of crop land also not optimal that signifcantly challenges to crop productivity.Therefore, this study was conducted to evaluate the effects of climate change on future crop water requirements, and irrigation scheduling, and to allocate cropland optimally. Bias of projected precipitation and temperature were corrected by utilizing Climate Model data with the hydrologic modeling tool (CMhyd). Alongside, crop water requirements and irrigation scheduling were assessed using Crop Water Assessment Tool. After estimating crop water requirement, crop land were allocated optimally using General Algebraic Modeling System programming with non-negativity constraints (scenario 1), and non-negativity constraints based on farmers adaptation (scenario 2). Average reference evapotranspiration from 2030 to 2050 and 2060 to 2080 was increased by 11.9 %, and 16.2 %, respectively compared with the reference period (2010-2022). The total seasonal crop water requirements were 4,529 mm, 4866.7 mm, and 5272.2 mm under 2010 to 2022, 2030 to 2050, and 2060 to 2080 climate change scenarios, respectively. The meean irrigation interval in 2010-2022, 2030 to 2050, and 2060 to 2080 climate change scenarios were 8 days, 7 days, and 5 days, respectively. This irrigation interval was decreased by 14 % (2030-2050), and 34 % (2060-2080) compared with the reference period. In 2030 to 2050 and 2026 to 2080 climate change scenarios, the required irrigation water at the inlet of main canal increased by 6.8 %, and 18 %, respectively. The optimal allocated area for tomato (60.4 %), maize (20.8 %), and watermelon (18.8 %) in scenario 1 with net benefit of 1.47108 Ethiopian Birr. The allocated areas in scenario 2 were (48 %) for maize, (31.6 %) for tomato, and (20.4 %) for watermelon with 1.3410 Ethiopian Birr net benefit it was reduced by 19.1 % compared with the net benefit in scenario 1. Fruit crops alone may not suffice for local food needs and to address this, small farmers should grow maize, tomato, and watermelon. This research aids policymakers in encouraging climate-resilient agriculture and improving small-scale farmers' awareness through conducting workshops and training.
埃塞俄比亚南部下库尔福集水区的作物需水量和灌溉调度在气候变化情景下尚未得到评估，而且作物土地分配也不理想，这对作物生产力构成了重大挑战。因此，本研究旨在评估气候变化对未来作物需水量和灌溉调度的影响，并优化作物土地分配。利用气候模型数据和水文建模工具（CMhyd）对预测的降水和温度偏差进行了校正。同时，使用作物水分评估工具评估了作物需水量和灌溉调度。在估算作物需水量后，使用具有非负约束的通用代数建模系统编程（情景1）和基于农民适应性的非负约束（情景2）对作物土地进行了优化分配。与参考期（2010 - 2022年）相比，2030年至2050年以及2060年至2080年的平均参考蒸发散分别增加了11.9%和16.2%。在2010年至2022年、2030年至2050年以及2060年至2080年气候变化情景下，季节性作物总需水量分别为4529毫米、4866.7毫米和5272.2毫米。2010 - 2022年、2030年至2050年以及2060年至2080年气候变化情景下的平均灌溉间隔分别为8天、7天和5天。与参考期相比，这个灌溉间隔在2030 - 2050年减少了14%，在2060 - 2080年减少了34%。在2030年至2050年以及2060年至2080年气候变化情景下，主渠入口处所需灌溉水量分别增加了6.8%和18%。情景1中番茄的最优分配面积为60.4%，玉米为20.8%，西瓜为18.8%，净收益为1.47×10⁸埃塞俄比亚比尔。情景2中的分配面积为玉米48%，番茄31.6%，西瓜20.4%，净收益为1.34×10埃塞俄比亚比尔，与情景1中的净收益相比减少了19.1%。仅水果作物可能无法满足当地的粮食需求，为解决这一问题，小农户应种植玉米、番茄和西瓜。本研究通过举办研讨会和培训，有助于政策制定者鼓励气候适应型农业并提高小农户的认识。
