Effects of heterogeneous land use/cover types on river channel morphology in the Solo River catchment,Eastern Uganda |
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| Authors: | Bernard Barasa Vincent Kakembo Tim Mwololo Waema Macopiyo Laban |
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| Institution: | 1. Department of Geosciences, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa;2. Geographical Information Systems Centre, Makerere University, Kampala, Uganda;3. Department of Land Resource Management and Agricultural Technology, University of Nairobi, Nairobi, Kenya |
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| Abstract: | In the tropics, unmonitored land use/cover types cause significant effects on the narrowing and widening of river channels which affects the integrity of water resources. River channel planform extent was characterized using Landsat images, while water and bedload samples were collected and analysed for a period of one year. The results revealed that in 1986, the channel planform covered 3.7 sq km in length than in 2013 where it increased to 4.2 sq km. Wetland (537.1mgl?1) and bushland (186.3mgl?1) cover types had the highest concentration of suspended sediments. Fine sand (0.25 mm), silty sand (1 mm) and silty clay (0.125 mm) bedload particle types dominated the riverbed along the channel from the sampled land use/cover types. The high concentration of sediments, bedload materials, bank instability, and streamflow were significant contributors to the narrowing and widening of the channel (p < 0.05). Agricultural land use was the major contributor of channel aggradation (0.8 m) and degradation (0.25 m) compared to tree plantations, bushlands, forest and wetland cover types. |
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| Keywords: | River channel planform sediments streamflow cross-sections |
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