The influence of a semi-arid sub-catchment on suspended sediments in the Mara River, Kenya

• DOI: 10.1371/journal.pone.0192828
• Publication Date: 2018-02-08T13:50:54Z
• Authors: Christopher L. Du...; Amanda L. Subalusky; Shimon C. Anisfeld; Laban Njoroge; Emma J. Rosi; David M. Post
• Keywords: Geologic Sediments; Periodicity; Arid; Climate; 02 engineering and technology; Sociology; Importance and Conservation of Freshwater Biodiversity; Rangeland Degradation and Pastoral Livelihoods; Artiodactyla; Water Science and Technology; Ecology; Geography; Q; R; Agriculture; Hydrology (agriculture); Geology; Structural basin; 6. Clean water; FOS: Sociology; Hydrological Modeling and Water Resource Management; Physical Sciences; Medicine; Research Article; Environmental Monitoring; Cartography; Drainage basin; Science; Population; 0207 environmental engineering; Management, Monitoring, Policy and Law; Environmental science; Rivers; Animals; Humans; Biology; Nature and Landscape Conservation; Demography; Environmental Flows; Geomorphology; FOS: Earth and related environmental sciences; 15. Life on land; Kenya; Geotechnical engineering; 13. Climate action; FOS: Biological sciences; Environmental Science; Hydrodynamics; Animal Migration; Cattle; Sediment

The Mara River Basin in East Africa is a trans-boundary basin of international significance experiencing excessive levels sediment loads. Sediment this river are extremely high (turbidities as 6,000 NTU) and appear to be increasing over time. Large wildlife populations, unregulated livestock grazing, agricultural land conversion all potential factors loads the semi-arid portion basin. well-known for its annual wildebeest (Connochaetes taurinus) migration approximately 1.3 million individuals, but it also has growing population hippopotami (Hippopotamus amphibius), which reside within may contribute flux suspended sediments. We used situ pressure transducers turbidity sensors quantify at two sites investigate origin riverine sediment. found that combined Middle Mara—Talek catchment, relatively flat region with large populations domestic cattle, responsible 2/3 flux. yield from Mara–Talek catchment same headwaters, despite receiving less rainfall. There was monthly variability fluxes. Although hippopotamus pools not major source sediments under baseflow, they do short-term This research identified sources important regions target conservation, suggests influence dynamics.