A Water Quality Study of the Selangor River, Malaysia

Malaysia’s rapid economic and demographic development has put pressures on its water supplies and consequently on the quality of its river water. The Selangor River, close to the nation’s capital, is now a major source of water and there are fears that its water quality will deteriorate. The Malaysian Government in its Vision for Water 2025 states that rivers should achieve Class II as measured by Malaysia’s Water Quality Index (WQI) (Class I is cleanest). The objectives of this thesis are to investigate the effects of flow through the 10 major tidal control gates (TCGs) which regulate run-off from the oil-palm plantations into the river, and to predict the water quality for the river in 2015, 2020 and 2030. In order to achieve these objectives it was necessary to set-up, calibrate and validate a commercial one-dimensional numerical model, InfoWorks, which includes both the hydrodynamics and water quality of the river-estuary network. It was concluded that there was insufficient hydrodynamic (stage and current) and water quality data to fully calibrate and validate the InfoWorks model but it performed well when compared with measured salinity transects. The model was found to be relatively insensitive to the choice of diffusion parameters but needed a high value for the oxygen transfer velocity, 0.3 m h-1, to get reasonable values for the dissolved oxygen (DO) along the river. The effect of run-off through the TCGs was less than expected and attributed to the high oxygen transfer velocity and needs to be addressed before the model can properly represent run-off through the TCGs. The model shows the WQI of the lower reaches of the river to be Class III in both wet and dry seasons except close to the estuary where it is Class II due to tidal flushing. The dissertation identifies several deficiencies in the model; the lack of an operational ramp function at the estuary boundary, the use of a single value of the oxygen transfer velocity throughout, and the exclusion of water extraction. Land-use changes above Rantau Panjang, the upper boundary of the InfoWorks model, and water quality data were used to estimate the water quality and its uncertainties at Rantau Panjang in 2015, 2020 and 2030 due to predicted development in the upper catchment for both wet and dry seasons. InfoWorks models of water quality along the river in 2015, 2020 and 2030, which included extraction at the Batang Berjuntai barrage, predict little change in the WQ (Class II/III boundary) below the barrage during the dry season but a rapid deterioration in the wet season (down to Class III/IV by 2030) showing the importance of water extraction to the water quality of the river. Overall, because of its relative simplicity and ease of operation, InfoWorks is considered to be a useful tool for river management in Malaysia

Land use change in highland area and its impact on river water quality: a review of case studies in Malaysia

The policy of encouraging agriculture and development for mass tourism has led to environmental problems in Cameron Highlands, Malaysia. Rampant development and land clearing have significantly altered the land cover of Cameron Highlands for the past 30 years. Sensitive highlands areas are prone to landslides and soil erosion which then contributed to the main water pollution issues in the network of river system, sedimentation and siltation. The continuous trend of river water quality deterioration in Cameron Highlands has raised the issues for discussion in this review article. The purpose of this review is to briefly summarize the land use change, agriculture practices, agro-tourism, and agriculture policy and management toward water quality of the river system network in Cameron Highlands specifically in the downtown where most of the development and agriculture activities are concentrated. A rigorous review has been done on the existing literature to determine the relationship between land use change and agriculture practices toward river water quality in Cameron Highlands from 2001 to 2017. The total number of reviewed papers was 68. The outcomes established from previous researchers have highlighted factors such as soil erosion, landslides, agriculture activities, urbanization, and unplanned development associated with land use change have significantly influenced the river water quality in the highland areas. Continuous land use changes without proper development plan and law enforcement may critically threaten the sustainability of river network in the highlands area

Heavy metals contamination and potential health risk in highland river watershed (Malaysia)

Introduction: Extensive agriculture activities in the upstream area causes pollutants flow to the downstream area and contaminate the drinking water resources. Methods: Water samples were collected from 27 sampling points of Bertam River in Cameron Highlands, during wet season in September 2017 for physicochemical properties and heavy metals analyses. Potential health risk was calculated based on the heavy metals concentration detected. Results: The pH value of the river ranged from neutral to slightly acidic (6.15-7.01). The overall mean level of turbidity (109.94 ± 160.73 NTU), DO (7.86 ± 0.71 mg/L), E. coli (5191.00 ± 14937.42 CFU/100 mL), and NH3-N (0.85 ± 0.54 mg/L) were exceeded the National Standard for Drinking Water Quality (NSDWQ) (Ministry of Health Malaysia). The concentration of heavy metals were in the following order; Fe>Al>Cu>Zn>Pb>Cd. The overall mean concentration of Cd (0.015 ± 0.007 mg/L), Fe (0.442 ± 0.191 mg/L) and Pb (0.021 ± 0.005 mg/L) were exceeded the national standard (NSDWQ). The non-carcinogenic health risk for adult and children from daily water consumption was within an acceptable risk. There is a potential cancer risk through Cd exposure in the drinking water where the risk higher among children (4.92 x 10-3), followed by adult male (3.06 x 10-3) and adult female (2.98 x 10-3). Conclusion: Significant heavy metals contamination and health risk through water consumption were observed in the highland river watershed, possibly due to the anthropogenic activities

Lake and Watershed Management: Issues and Challenges in Managing Lake Water Quality

Abstract -High-intensity land-use activities occur near lakes including in their watershed and increase of population density in areas neighbouring the lakes have caused overexploitation of lake water resources and discharge of large volumes of pollutants into lakes water. As a consequence led to escalating deterioration of lake water quality. Water quality conditions of lakes are significantly influence by their watershed behaviours. The lentic nature of lakes allows problems to build up and symptoms to go unnoticed for a lengthy period and commonly only appearing at a delayed and dangerous stage given that similarly a slow and often equally long period is needed to treat before positive results begin to show again. Hence, it is quite complex to comprehend types and strengths of pressures that impact water quality status, when do the changes will occur and what the status of water quality would be, not only on the presence situation but over the long term. Lake water quality and catchment relationship is an intricate issue and required the lake managers and planners to be attentive and prepared to engage in sustained actions over a long-term time frame relating to the development of lakes because progression of degradation inside a lake mostly takes place on a wider and deeper scale than is readily apparent. The comprehensive understanding on anthropogenic upheaval and hydrological linkages within lake watershed influences the dynamics of the lake water quality and is vital to the resulting livelihood including the cultural, biodiversity, and economic activities that are supported by lakes. This paper highlights the issues and challenges in managing lake water quality, variables that significantly influence lake catchment-water quality relationship, discussing the water quality parameters that must be regularly monitored, and proposing a management support tool as the expected research output to ensure lake water quality is not compromise while meeting the country's socio-economic demand

Erosion risk index: Correlation of ROM-scale and Mackintosh Probe at Sungai Langat tributary

The assessment of soil erosion risk has been widely studied, and various methods have been established. However, most of the methods require extensive field and laboratory works that are time-consuming. The previous literature mainly focused on utilizing the existed empirical models like USLE and its derivatives. The establishment of empirical correlation can increase the efficiency to estimate the potential of soil erosion in a shorter time. This study was performed to develop an empirical correlation between the number of blows per unit penetration (M-value) obtained from Mackintosh Probe test and ROM-scale number from soil particle size distribution analysis. Both tests were conducted at three different points at one of Sg. Langat tributary riverbank nearby Universiti Kebangsaan Malaysia, Bangi. The soil at each location was analyzed at three different layers, from 0 m to 1.5 m with intervals of 0.3 m and 0.5 m for Mackintosh Probe test and ROM-scale, respectively. The result indicates that ROM-scale umber is inversely proportional to M-value with a coefficient of determination of 0.5885