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Spatial and temporal variations of sedimentation rate in the Timah Tasoh Water Reservoir, Perlis, Malaysia

100%

Rahaman Z. A., Ismail W. R.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2010

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tom 42

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nr 1

127-138

Human activities such as logging, land conservation, road construction and other disturbances in watersheds will increase erosion rate and thus the amount of sediment transported into the river that reaches lakes, reservoirs and sea. Accelerated sedimentation rate in the reservoir can signifi cantly reduce a reservoir’s surface area, eliminating wetland area surrounding the reservoir and shallow the areas near the shore of the reservoir. A study of sedimentation rate in the Timah Tasoh water reservoir was carried out from May 2001 to April 2002 by means of sediment traps. The aim of this study is to determine the spatial and temporal pattern of sedimentation rates in the reservoir. The sediment traps were installed at five different locations in the reservoir and replaced every month. Gross sedimentation rates measured in the sediment traps vary from about an average of 1.4 kg/m2/month or 16.3 kg/m2/yr in the deepest part of the reservoir to about 79.2 kg/m2/yr (monthly average of 6.6 kg/m2/month) and 47.1 kg/m2/yr (monthly average of 3.9 kg/m2/month) near the inlet of the Pelarit River and the Tasoh River respectively. The sedimentation rate near the Pelarit River and the Tasoh River inflow is correlated with the water and suspended sediment discharge in the river, owing to its proximity to the rivers and the fl ooding effect, mainly during the wet season. The sedimentation rate decreases southward along the reservoir, as a result of increasing distance from the river mouth. The total suspended sediment load of the Upper Pelarit River and the Jarum River flowing into the reservoir is 11.4 × 103 ton/year and 5.41 × 103 ton/ /year respectively.

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Dominant discharge in the Indus river from downstream of the Kotri barrage dam

100%

Radecki-Pawlik A., Laszek W., Plesinski K., Khan Lashari B.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2014

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tom 13

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nr 4

Hydraulic data of the Indus River, downstream of Kotri Barrage dam are analyzed. An attempt has been made to determine the dominant discharge, which is defined as that discharge which over a long time period transports the most sediments and could be used to predict the shape of river cross-section. For dominant discharge calculation Wolman and Miller’s approach has been applied. Since the transport of sediment concentration could be a more effective variable for forming the shape of the river cross-section, suspended sediment concentration has been introduced, because more than 85% of total load is in suspension. We show in the paper that water discharge Q = 1000 m³ · sˉ¹ of water is a frequent discharge and carries maximum sediment load. This discharge we call here the dominant discharge (Qdd) for the Kotri dam cross section.

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The transport of material by the rivers of the Northern slope of the Pomeranian Lakeland to the Baltic Sea

100%

Szymczak E.

Oceanological Studies

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2002

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tom 31

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nr 3-4

Ograniczanie wyników

1 Acta Scientiarum Polonorum. Formatio Circumiectus

1 Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

1 Oceanological Studies

1 Ismail W. R.

1 Khan Lashari B.

1 Laszek W.

1 Plesinski K.

1 Radecki-Pawlik A.

1 Rahaman Z. A.

1 Szymczak E.

1 2014

1 2010

1 2002

Spatial and temporal variations of sedimentation rate in the Timah Tasoh Water Reservoir, Perlis, Malaysia

Dominant discharge in the Indus river from downstream of the Kotri barrage dam

The transport of material by the rivers of the Northern slope of the Pomeranian Lakeland to the Baltic Sea