This study aimed to analyze the status and evaluate the spatiotemporal variabilities of water quality in the Awash River, Ethiopia. The study also aims to identify the origin and geochemical composition of the river water. Temporal variabilities of similar water quality parameters in the Lake Beseka, a dramatically rising lake (0.2 m/year) in the Awash River basin, which is being channeled into the Awash River system in order to control the lake level rise, were also considered in this study. To do this, laboratory measurements and a 10-year consecutive record of physicochemical parameters, major ions, nutrients and minor ions of the Awash River and Lake Beseka waters, graphical methods and factor analysis approaches were used. The origin of the Awash River was found to be shallow-medium depth aquifer with a geochemical composition of Ca(HCO₃)₂ and NaHCO₃, while the origin of Lake Beseka was found to be deep, ancient groundwater with a geochemical composition of NaCl and NaHCO₃. However, mixing the lake water with Awash River in the downstream sites shifted the geochemical composition of the river water to a mixture of Ca(HCO₃)₂, NaHCO₃ and NaCl water types. The results also showed that the river water quality varies spatially and temporally, controlled by three major factors: the combined effects of anthropogenic activities and mineral dissolutions (Factor-1), anthropogenic activities and ion exchange (Factor-2) and ion exchange (Factor-3). While Factor-1 was the main controlling factor of the river water quality, and Factor-3 was the least, all three factors equally controlled the temporal variabilities of water quality in Lake Beseka. The observed temporal and spatial variabilities of the river water quality suggest that frequent water quality evaluations are important in designing appropriate water management strategies in river systems near intensive agricultural, industrial, and urban development areas.

中文翻译：

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河流水质参数时空变化分析与评价

本研究旨在分析埃塞俄比亚阿瓦什河的现状并评估水质的时空变化。该研究还旨在确定河水的来源和地球化学成分。在Beseka湖中，类似水质参数的时间变化也被认为是在Awash河流域中急剧上升的湖泊（每年0.2 m /年），为了控制湖泊水位的上升，该湖被引入Awash River系统。这项研究。为此，使用了实验室测量值以及Awash河和Beseka湖水的理化参数，主要离子，养分和次要离子的十年连续记录，图形方法和因子分析方法。发现阿瓦什河的起源是具有化学成分Ca（HCO）的浅中深度含水层。₃）₂和NaHCO ₃，而发现Beseka湖的起源是深层的古老地下水，其地球化学成分为NaCl和NaHCO ₃。然而，在下游站点将湖水与阿瓦什河混合，将河水的地球化学组成转变为Ca（HCO ₃）₂，NaHCO ₃的混合物。和氯化钠水类型。结果还表明，河流水质在时空上受三个主要因素控制：人为活动和矿物质溶解的综合影响（因子1），人为活动和离子交换（因子-2）和离子交换（因子-3）。因子1是影响河流水质的主要控制因素，而因子3则是最不重要的因素，但所有这三个因素均平等地控制了比塞卡湖的水质随时间变化。观察到的河流水质的时空变化表明，频繁的水质评估对于在农业，工业和城市密集开发区附近的河流系统中设计适当的水管理策略非常重要。