The Awash River basin is classified into the upper basin, middle basin, and lower basin. The upper basin is the most irrigated and socio-economically important, wherein early and modern agriculture started. This study aimed to assess the upper basin’s hydroclimate variability under climate change from 1991 to 2015 following the county’s land-use policy change. Distinguished topographical settings, namely, lowland, midland, and highland, are used for upper Awash basin hydroclimate trend analysis. Lowland stations revealed a nonsignificant seasonal and annual increasing trend except for the Autumn season. Midland stations showed a decreased seasonal rainfall. Except for Sendafa, the increased station, the highland area exhibited an annual decreasing trend. The Awash-Hombole and Mojo main tributaries are used for the evaluation of basin streamflow. The Awash-Hombole main tributary resulted in annually growing trends during the summer season. Mojo main tributary resulted in a significantly decreasing trend during the spring, summer, and autumn seasons with a 99% level of significance. Therefore, following the basin’s topographic nature, the change of hydroclimatic elements, mainly of the rainfall and streamflow, is observed. Accordingly, its hydroclimate variated by 11 and 38% with precipitation and streamflow, respectively, from the mean value within the study time series.

中文翻译：

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埃塞俄比亚上阿瓦什盆地水文气候趋势分析

阿瓦什河流域分为上流域、中流域和下流域。上流域是灌溉最多、社会经济最重要的流域，早期和现代农业在此发源。本研究旨在评估 1991 年至 2015 年随着该县土地利用政策变化的气候变化下上流域的水文气候变异性。不同的地形设置，即低地、中部和高地，用于上阿瓦什盆地的水文气候趋势分析。除秋季外，低地站显示出不显着的季节性和年度增长趋势。米德兰站显示季节性降雨量减少。除增加的森达法站外，高原地区均呈现逐年减少的趋势。Awash-Hombole 和 Mojo 主要支流用于评估盆地水流。Awash-Hombole 主要支流导致夏季每年呈增长趋势。Mojo 主要支流导致在 春、夏、秋三季，显着性水平为 99%。因此，根据流域的地形性质，观察到主要是降雨和水流的水文气候要素的变化。因此，它的水文气候与研究时间序列内的平均值分别随降水和水流变化 11% 和 38%。