Authors : M.E. Toriman, A.C. Er, Mazlin Mokhtar, Rahmah Elfithri, Muhammad Barzani Gasim, Othman Karim, Mokhtar Jaafar, Nor Azlina Abdul Aziz and Nor Rohaizah Jamil
Abstract: River regulation is a process of alteration of stream flow for water resources and hydropower. Most regulation structures involved dams and weirs which are able to control the flow regimes for special requirements, i.e., agriculture, domestic and industrial power. This study examines channel geometry change in particular their planform characteristic due to intensive regulation by the Pangson and Semenyih reservoirs on the Langat river over the last 12 years. GIS-ArcInfo extrapolation analysis was used to quantify the geometry change. Superimposed topographical maps of pre (1973) and post regulated (1985) were successful to determined type and pattern of channel planform change. Examination of planform indices represented by three-point stations in the upland, intermediate and lowland reaches indicate that in general, channel sections tend to be straighter in the upland and become narrower with more meandering in the intermediate and lowland reach sections. These were proven quantitatively using Sinuosity Index (SINDX). In the upland reach, the SINDX was reduced to average 1.02-0.99 post-regulation while the others demonstrate the opposite trend.
M.E. Toriman, A.C. Er, Mazlin Mokhtar, Rahmah Elfithri, Muhammad Barzani Gasim, Othman Karim, Mokhtar Jaafar, Nor Azlina Abdul Aziz and Nor Rohaizah Jamil, 2011. River Regulation and its Impact on River Channel Planform Changes. Journal of Engineering and Applied Sciences, 6: 423-427.