Urban impact on ecological integrity of nearby rivers in developing countries: The Borkena River in highland Ethiopia
Environmental Monitoring and Assessment
Plant Science and Nature Management (APNA), Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium; Environmental Health, Jimma University, P.O. Box 378, Jimma, Ethiopia; Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94143, United States
Accelerated pollution and eutrophication of rivers and streams because of human activity are a concern throughout the world and severe in Africa where Ethiopia is case in point. The objective of this study was to assess the urban impact on the ecological integrity of the Borkena River at the eastern escarpment of the central Ethiopian highlands. The water quality status and macroinvertebrate distribution and diversity of the river were assessed during the dry and wet seasons. Diversity indices revealed that a severe decline in the ecological integrity of the Borkena River downstream of Dessie and within Kombolcha towns in terms of macroinvertebrate abundance and composition. Clustering and ordination analysis clearly separated reference sites from urban impacted sites. At the urban-impacted sites, dissolved oxygen was also depleted to 0.5 mg/l and BOD5 values were reached to a level of above 1,000 mg/l, with extremely low biological diversity of pollution-sensitive taxa. These patterns are the result of a combination of rampant dumping of untreated wastes exacerbated by geologic, topographic, climatic and land use factors. © Springer Science+Business Media B.V. 2008.
Borkena river; Ecological integrity; Ethiopia; Faunal diversity; Macroinvertebrate; Developing countries; Dissolution; Dissolved oxygen; Eutrophication; Land use; Natural resources; Pollution; Quality assurance; Rivers; Water quality; River pollution; dissolved oxygen; cluster analysis; developing world; dissolved oxygen; environmental impact; Index of Biotic Integrity; macroinvertebrate; river water; species diversity; water quality; article; biochemical oxygen demand; biodiversity; climate; cluster analysis; controlled study; dumping; environmental impact; Ethiopia; eutrophication; geology; human activities; land use; macroinvertebrate; population abundance; river ecosystem; season; taxon; topography; urban area; water pollution; water quality; Ecology; Environmental Monitoring; Environmental Pollution; Ethiopia; Geography; Rivers; Africa; Borkena River; Dese; East Africa; Ethiopia; Sub-Saharan Africa