Ahmednur Mahmud, Sabir Remla, Lenjissa Dechassa, Ambelu Argaw
Department of Environmental Health Sciences and Technology, Institute of Health, Jimma University, Jimma, Ethiopia.
Environmental Health, Division of Water and Health, Ethiopian Institute of Water Resources, Addis Ababa University, Ethiopia.
Heliyon. 2024 Nov 29;10(23):e40778. doi: 10.1016/j.heliyon.2024.e40778. eCollection 2024 Dec 15.
Freshwater ecosystems are increasingly modified worldwide by anthropogenic activities. Land use change is one of the leading factors responsible for stream ecosystem degradation. Physical habitat disturbance due to channelization is among the factors responsible for the loss of biodiversity and degradation of river water quality worldwide. Since 2020, Jimma City municipality has been beautifying the city and one of the activities is channelizing using concrete embankment, a part of the Awetu stream that runs through the city. The main aim of this study is to assess the effect of channelization on macroinvertebrate assemblages and the water quality of the Awetu stream. A cross-sectional study was conducted in April 2022. Macroinvertebrates, water samples, and habitat data were collected from 21 sampling sites along the three segments of the stream (upstream, channelized, and downstream). Data were analyzed for different macroinvertebrate metrics and water quality parameters. Canonical Correspondence Analysis was used to examine the overall relationship between macroinvertebrate assemblages and water quality parameters. The upstream site has better macroinvertebrate assemblages than channelized and downstream sites (p < 0.05). The downstream site showed better assemblage compared to the channelized site, though it was not significant. Regarding water quality parameters, a significant variation was observed between channelized and, un-channelized sites (upstream and downstream) (p < 0.05). The habitat condition score varied from 47 (poor) at channelization to 150 (suboptimal) upstream. Upstream sites were found to have relatively better macroinvertebrate assemblages, better water quality, and good habitat conditions. The downstream sites had lower macroinvertebrate assemblages, poor habitat conditions, and degraded water quality compared to the upstream sites. The channelized segment had the poorest habitat, with poor macroinvertebrate assemblages and water quality. Thus, the conservation of habitat conditions along the channelized segments of the Awetu stream is recommended to improve the water quality and macroinvertebrate assemblage.
在全球范围内，淡水生态系统正日益受到人为活动的影响而发生改变。土地利用变化是导致河流生态系统退化的主要因素之一。渠道化造成的物理栖息地干扰是全球生物多样性丧失和河流水质退化的原因之一。自2020年以来，吉姆马市一直在进行城市美化，其中一项活动是使用混凝土堤岸进行渠道化，阿韦图溪流的一部分流经该市。本研究的主要目的是评估渠道化对阿韦图溪流大型无脊椎动物群落和水质的影响。2022年4月进行了一项横断面研究。从溪流的三个段（上游、渠道化段和下游）的21个采样点收集了大型无脊椎动物、水样和栖息地数据。对不同的大型无脊椎动物指标和水质参数进行了数据分析。典范对应分析用于检验大型无脊椎动物群落与水质参数之间的总体关系。上游采样点的大型无脊椎动物群落比渠道化段和下游采样点更好（p < 0.05）。与渠道化段相比，下游采样点的群落状况更好，尽管不显著。关于水质参数，渠道化段与未渠道化段（上游和下游）之间存在显著差异（p < 0.05）。栖息地条件评分从渠道化段的47（差）到上游的150（次优）不等。发现上游采样点的大型无脊椎动物群落相对较好，水质较好，栖息地条件良好。与上游采样点相比，下游采样点的大型无脊椎动物群落较少，栖息地条件较差，水质退化。渠道化段的栖息地最差，大型无脊椎动物群落和水质都很差。因此，建议保护阿韦图溪流渠道化段的栖息地条件，以改善水质和大型无脊椎动物群落。
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