GIS‐based surface irrigation potential assessment of Gololcha River Watershed, Awash Basin, Ethiopia

The Gololcha River Watershed is lacking comprehensive assessment of land suitability for surface irrigation, available water potential, and prioritized irrigable areas. This study aims to evaluate the potential of land and water resources for surface irrigation in the Gololcha River Watershed. The study employed a multi‐criteria analysis approach using the analytical hierarchy process (AHP) and ArcGIS to assess land suitability, considering factors like slope, land use/cover, soil characteristics, and proximity to water sources. The observed mean monthly water flow potential for each sub‐watershed was statistically evaluated, and the area ratio approach was used to transfer discharges from gauged sites to the site of interest. Irrigation water requirements for three major crops in the study area were calculated using the CROPWAT8.0 model. The findings revealed an average water availability for irrigation of 2.70 m 3 /s/month, 1.10 m 3 /s/month, and 1.03 m 3 /s/month for the Kurkura, Midagdu, and Wefi sub‐watersheds, respectively, with a total annual river flow of 161 m 3 /s. Based on the suitability analysis, 2508 ha (7.27%) of the watershed area was classified as highly suitable for surface irrigation, 16,420 ha (47.565%) as moderately suitable, 1502 ha (4.35%) as marginally suitable, and 14,029 ha (40.71%) as unsuitable. The overall surface irrigation potential, aligned with available water, was estimated at 4872.58 ha. However, due to water limitations, only 14.15% of the total suitable land can be irrigated using existing flows. The study highlights the significant potential for expanding surface irrigation in the Gololcha River Watershed, particularly during the rainy seasons when substantial water flows are available. The findings provide valuable insights for developing sustainable irrigation strategies, enhancing agricultural productivity, and contributing to food security in the region. Gololcha河流域缺乏对“地面灌溉的土地适宜性、可用水潜力和优先灌溉区域”的综合评估。本研究旨在评价Gololcha河流域土地和水资源在地面灌溉方面的潜力。本研究采用多标准分析方法, 使用层次分析法 (AHP)和ArcGIS来评估土地适宜性, 并考量了坡度、土地利用/覆盖、土壤特征和“与水源的距离”等因素。对每个子流域观测到的平均每月水流量潜力进行了统计评价, 并使用面积比方法将排放量从测量点转移到目标点。使用CROPWAT8.0模型计算了研究区域内三种主要作物的灌溉用水需求。研究结果显示, Kurkura、Midagdu和Wefi子流域的平均灌溉水可用量分别为每月2.70立方米/秒、1.10立方米/秒和1.03立方米/秒, 年河流总流量为161立方米/秒。根据适宜性分析, 2508公顷(7.27%)的流域面积被归类为非常适合地面灌溉, 16,420公顷(47.565%)为中等适宜, 1502公顷(4.35%)为边缘适宜, 14,029公顷(40.71%)为不适宜。与可用水量相匹配的整体地面灌溉潜力估计为4872.58公顷。然而, 由于水资源限制, 只有14.15%的总适宜土地能利用现有流量进行灌溉。本研究强调了“扩大Gololcha河流域地面灌溉”一事的巨大潜力, 特别是在雨季, 因为雨季有大量水流。研究结果提供了宝贵