River Flow Conditions and Dynamic State Analysis of Pahang River

Abstract

Pahang River (Sg. Pahang) is the longest river in Peninsular Malaysia. Flood is a common event in Pahang River Basin during wet season which triggered by monsoon season. The hydrodynamic study of Pahang River should be well understood especially when it is a target of northeast monsoon which influenced the Pahang River Basin every year (from November to March). 17 river cross section stations were selected and used to measure its drainage capacity, hydraulic parameters and estimation of flow discharge. Long term (1980 to 2009) variation of hydrologic data series comprised of river flow, river stage and rainfall data were analyzed based on the Department of Irrigation and Drainage (DID) Malaysia record. Monthly rainfall was recorded from Sg. Yap, Temerloh and Lubuk Paku Rainfall Stations. Two hydrologic sampling trips had been carried out; first sampling on January 2010 and second sampling on February 2010. The study indicates that velocity and river flow measurement during first sampling ranged from 0.308 to 0.582 m sec −1 and 153.282 to 439.684 m 3 sec −1 . Meanwhile, during second sampling, the velocity and river flow ranged from 0.217 to 0.484 and 52.071 to 304.485 m 3 sec −1 , respectively. Floods were occurred annually at Pahang River especially during northeast monsoon, these events are expected to be stimulated by the inconsistent condition of width and depth along Pahang River which finally create sedimentation and meandering characteristic.

RETRACTED: Hydrological and climate impacts on river characteristics of Pahang River Basin, Malaysia

“…22 (b), the R 2 is equal to 0.66. From the hypothesis testing, it appears that the correlation between Sinuosity Index (SI) and water level is considered moderate as it is between 0.50 and 0.70 [ [114] , [115] , [116] , [117] , [118] ]. Based on these results, the changes in the Pahang River planform can be indicated and reliable by analysing the discharge of the river, and in this case, water level was used to represent discharge.…”

Low Flow Frequency Analysis at Triang River Streamflow Station

“…After that, February is said to be the driest month of the year while May is the hottest. Within these months, extreme weather conditions may occur and can lead to a drastic change in the rivers [6].…”

The Assessment of Sedimentation Problems in Kenyir Hydropower Reservoir, Malaysia

“…Among the characteristics are the erosion caused by stream flow turbulence, the side erosion that finally causes the bank structure to collapse, landslip caused by a rise in bank slope, and the removal of soil particles on riverbanks as a result of flow regime. Water is a powerful symbol of transportation that may both protract soils and remove and sweep them away, creating an unstable riverbed morphology [28][29][30]. According to [31], it has been established that the hydrological features, erosion of soil, land use practices, topography and geomorphological elements, dam capacity, and water flow rate are all contributing factors to the sedimentation issue in the Kenyir generating reservoir.…”

“…Table 1a,b shows the current and future (100-year ARI) results of sediment load production for each sub-catchment along the Kenyir Lake Basin based on forest coverage reduction percentage [31]. Based on secondary and primary data obtained, the average erosion rate around the research area is assumed to be 'low', which is to be expected for a dominantly forested geographical area of medium elevation and slope [11,[30][31][32]. The Kenyir Hydropower Reservoir's sedimentation issues are not yet critical, but they will become so if more through monitoring programmes and coordinated lake basin management are not recommended to protect and safeguard the catchment, particularly close to the Kenyir Dam, Tembat Dam, and Puah Dam, in order to prevent significant soil erosion.…”