Selangor River Research Articles

Microplastic Contamination and Ecological Risk Assessment in Tropical Riverine Surface Water of Selangor River Basin, Malaysia

Microplastic Contamination and Ecological Risk Assessment in Tropical Riverine Surface Water of Selangor River Basin, Malaysia

Assessment of Water Quality and Heavy Metals Concentration in Selangor River

Assessment of Water Quality and Heavy Metals Concentration in Selangor River

Seasonal variations in the distribution of aliphatic hydrocarbons in surface sediments from the Selangor River, Peninsular Malaysia's West Coast.

The seasonal variation of petroleum pollution including n-alkanes in surface sediments of the Selangor River in Malaysia during all four climatic seasons was investigated using GC-MS. The concentrations of n-alkanes in the sediment samples did not significantly correlate with TOC (r = 0.34, p > 0.05). The concentrations of the 29 n-alkanes in the Selangor River ranged from 967 to 3711 µg g-1dw, with higher concentrations detected during the dry season. The overall mean per cent of grain-sized particles in the Selangor River was 85.9 ± 2.85% sand, 13.5 ± 2.8% clay, and 0.59 ± 0.34% gravel, respectively. n-alkanes are derived from a variety of sources, including fresh oil, terrestrial plants, and heavy/degraded oil in estuaries. The results of this study highlight concerns and serve as a warning that hydrocarbon contamination is affecting human health. As a result, constant monitoring and assessment of aliphatic hydrocarbons in coastal and riverine environments are needed.

Sonneratia sp. as a phytoremediator potential of selected heavy metal contamination on mangrove sediment along Selangor River in Peninsular Malaysia

This study aimed to examine Sonneratia sp as a potential plant for phytoremediation of selected heavy metal contamination of mangrove sediment in Peninsular Malaysia. Five stations were established along Selangor riverbanks under Sonneratia sp trees zone. Five sub-plots (2 m x 2 m) were established for samples collection each plot. Collected samples were prepared and analysed in the laboratory. There was a significant difference of selected heavy metal concentration on sediment and on Sonneratia sp (roots, barks and leaves) between five stations for Zn and Cr, while it was not significant difference for Cu, Pb and Cd. Bio-concentration Factors (BCF) also revealed the species ability to contain elements absorbed differed by vegetative parts where higher average accumulation occurred in leaves for Zn (0.363) and Cd (0.633), in barks for Pb (0.070) and Cr (0.396), while in roots for Cu (2.242). Translocation factor (TF) of Cr in barks was the most concentrated vegetative parts per elements measured in roots at ratio of 1.814 while the lowest was Pb in leaves at 0.515. Sonneratia caseolaris is a good vegetation for uptake the heavy metal from mangrove and can be recommended as a phytoremediation potential of heavy contamination of mangrove sediment.

Best Practice Approach to Stage-Discharge Rating Curve: Case Study of Selected Rivers in Selangor

A stage-discharge rating curve represents the relationship between the water level at a given point in a stream and a corresponding volumetric rate of flow. It is widely used for the analysis of flow regimes, designing hydraulic structures, flood forecasting, flow-sediment interaction and prediction, and river channel analysis. The reliability and stability of the stage-discharge rating curve are based on numerous numbers of discharges and stage data from the lowest to the highest bank full stage observed over a long period of time. Stage-discharge rating curves contribute to reliable discharge prediction for future flood forecasting. This study focuses on the best-practice approach to stage-discharge rating curve development for selected rivers in Selangor. The stagedischarge rating curve derived was evaluated in terms of the statistical parameter, which denotes the degree of determination or r-squared value. The polynomial function yields better accuracy at 68.6% than the exponential function at 60.3%. Model validation was performed using the discrepancy ratio and confirmed that the stagedischarge rating curve developed using both mathematical functions give good predictions with more than 80% accuracy for the specified flow range and stage levels.

Heavy Metal Concentration in Mangrove Soils under Sonneratia caseolaris Trees: The Case of Kampung Kuantan Fireflies Park

The local ecosystem potentiality is pressurized by the getting up heavy metal concentrations, especially in Kampung Kuantan Fireflies Park. This mangrove forest park, which is dominated by Sonneratia caseolaris, is a well-known place to visit for people who like nature in Kuala Selangor Peninsular Malaysia. However, the investigations on heavy metal concentration in mangrove soils under S. caseolaris are still limited. This study aims to find out the concentration of heavy metal in mangrove soil under S. caseolaris. The soil samples were taken from under S. caseolaris trees zone. Five plots were built up on mangrove soils through the Selangor River. Five sub-plots, each measuring 2 m ´ 2 m, were made for sample collection in each plot. The heavy metal contents and the geo-accumulation index (I-geo) were evaluated. As the results, the concentration of heavy metals on soils such as zinc (Zn), copper (Cu), lead (Pb), chromium (Cr), and cadmium (Cd) under the S. caseolaris trees of 240.24 mg/kg, 6.89 mg/kg, 25.46 mg/kg, 34.88 mg/kg, and 0.14 mg/kg, respectively. The I-geo ratio indicated that the soils have low heavy metal deposits, with Cd having the lowest concentration and Zn having the highest. There is a significant difference between Zn and Cr concentrations on the soils in five plots, but there are no significant differences for Cu, Pb, and Cd. In general, the heavy metal contents throughout the sampling area were considered not polluted, since the amount of trace elements in the soil was relatively low compared to the average limit. Keywords: heavy metal, Kampung Kuantan Fireflies Park, Kuala Selangor, mangrove, Sonneratia caseolaris

The economic impact of water supply disruption from the Selangor River, Malaysia

Abstract The insidious economic impact of water disruption has received less attention compared to palpable climate disasters, but climate change and water security concerns call for investigation on cost consequences of property values and business losses in an already fragile water supply-demand balance in many developing countries. The economic impact of frequent water supply disruptions from the Selangor River in Malaysia due to technical issues, water pollution, and climate-related problems was estimated using the stock flow measure to assess property at risk, and survey to estimate business loss. The findings revealed that commercial, residential, and industrial property valued at RM459,041 million in 2020 in the State of Selangor and parts of Kuala Lumpur were at risk due to frequent water supply disruptions. A survey of small and medium enterprises from the manufacturing, construction, and services sectors revealed that 46% of the respondents were affected with losses amounting to RM2,053 million. The total economic impact of water supply disruption in 2020, combining both property value at risk and business loss, amounted to RM461,094 million, which accounted for 34% of Malaysia's GDP. A number of recommendations are made to prevent the widespread occurrence of water disruptions.

Microplastic Pollution in Freshwater Sediments: Abundance and Distribution in Selangor River Basin, Malaysia

Microplastic Pollution in Freshwater Sediments: Abundance and Distribution in Selangor River Basin, Malaysia

Trend study on COVID-19 pandemic lockdown impact on rivers in Selangor, Malaysia

According to the Department of Environment, numerous rivers, and streams in Selangor, and practically all rivers, are in the 'polluted' and ‘slightly polluted' category even before the COVID-19 outbreak (DOE, 2022). Due to a lack of anthropogenic activities such as industrial discharge, agricultural, poultry, sediment, and silt erosion, the trend of pandemic lockdown on water quality parameters in Selangor is expected to decline. The goal of this research is to see if contamination of water resources and rivers increases or decreases during a pandemic by examining the trajectory of water quality parameters in relation to the COVID-19 pandemic, to figure out which parameters are affecting pollution in Selangor rivers, and to emphasize the water quality in each river for DOE (2022), utilizing data from 2016 to 2020. The results of the investigation revealed significant variations in water and wastewater quality over time. Finally, it showed positive changes during the pre-pandemic and pandemic lockdown periods. DO, TSS, ammoniacal nitrogen, and turbidity exhibited positive effects on water quality metrics during the pandemic lockdown period, however, BOD, COD, and pH levels had negative effects.

Spatio-Temporal Analysis of Leptospirosis Hotspot Areas and Its Association With Hydroclimatic Factors in Selangor, Malaysia: Protocol for an Ecological Cross-sectional Study

Leptospirosis is considered a neglected zoonotic disease in temperate regions but an endemic disease in countries with tropical climates such as South America, Southern Asia, and Southeast Asia. There has been an increase in leptospirosis incidence in Malaysia from 1.45 to 25.94 cases per 100,000 population between 2005 and 2014. With increasing incidence in Selangor, Malaysia, and frequent climate change dynamics, a study on the disease hotspot areas and their association with the hydroclimatic factors would further enhance disease surveillance and public health interventions. This study aims to examine the association between the spatio-temporal distribution of leptospirosis hotspot areas from 2011 to 2019 with the hydroclimatic factors in Selangor using the geographical information system and remote sensing techniques to develop a leptospirosis hotspot predictive model. This will be an ecological cross-sectional study with geographical information system and remote sensing mapping and analysis concerning leptospirosis using secondary data. Leptospirosis cases in Selangor from January 2011 to December 2019 shall be obtained from the Selangor State Health Department. Laboratory-confirmed cases with data on the possible source of infection would be identified and georeferenced according to their longitude and latitudes. Topographic data consisting of subdistrict boundaries and the distribution of rivers in Selangor will be obtained from the Department of Survey and Mapping. The ArcGIS Pro software will be used to evaluate the clustering of the cases and mapped using the Getis-Ord Gi* tool. The satellite images for rainfall and land surface temperature will be acquired from the Giovanni National Aeronautics and Space Administration EarthData website and processed to obtain the average monthly values in millimeters and degrees Celsius. Meanwhile, the average monthly river hydrometric levels will be obtained from the Department of Drainage and Irrigation. Data are then inputted as thematic layers and in the ArcGIS software for further analysis. The artificial neural network analysis in artificial intelligence Phyton software will then be used to obtain the leptospirosis hotspot predictive model. This research was funded as of November 2022. Data collection, processing, and analysis commenced in December 2022, and the results of the study are expected to be published by the end of 2024. The leptospirosis distribution and clusters may be significantly associated with the hydroclimatic factors of rainfall, land surface temperature, and the river hydrometric level. This study will explore the associations of leptospirosis hotspot areas with the hydroclimatic factors in Selangor and subsequently the development of a leptospirosis predictive model. The constructed predictive model could potentially be used to design and enhance public health initiatives for disease prevention. PRR1-10.2196/43712.

The Analysis of Large Dam Impacts on Sediment Grain Size Distribution in a Tropical River System

Sedimentation is a natural phenomenon of rivers that is enhanced by modification of the river basin. The presence of dams delays the exchange of sediments, nutrients, and organisms between the terrestrial and aquatic environments. This article assesses the impact of the Selangor dam on the sediment grain size distribution and its association with river velocity and discharge. The fieldwork for sampling is conducted in the normal and rainy seasons. The samples were analyzed through a sieve analysis procedure to determine the particle size of the sediments. After the sieve analysis technique, GRADISTAT analysis was performed on the output. The GRADISTAT analysis classifies the sediments between sandy gravel and sand, and the median grain size (D50) ranges from 4.00 to 0.18 mm. The spatial distribution of the D50 shows that the bed-load sediments of the upper Selangor River are becoming fine-grained downstream. The skewness of the sediments differs from 0.86 to 8.44, which indicates that the sediments are poorly to moderately well sorted. The Spearman's correlation of the D50 and river velocity and discharge determine no association of the D50 with river velocity and discharge. The stations near Selangor Dam have high slopes and receive "sediment hungry" water that washes small-sized sediments; therefore, the upper stations have a more significant amount of gravel and large sand. Doi: 10.28991/CEJ-SP2023-09-02 Full Text: PDF

A New Model for Organic Contamination Assessments Using Benthic Macroinvertebrates as Biological Indicators

The main goal of this study was to develop a model for organic pollution assessment. Seven sampling sites in six rivers in the Rawang sub-basin, Selangor River, Malaysia, were selected with one reference site. The sampling sites near the fish farm were used to develop the model. SR2 was used for the validation of the developed model. Benthic macroinvertebrates and water sampling were conducted from April 2019 to March 2020. The Principal Components Analysis (PCA) and regression were conducted to select the most representing benthic macroinvertebrates family. Based on the score value (variance coefficient) of each benthic macroinvertebrates family, the cumulative score value of each sampling site was calculated (i.e., 18=6 sampling sites x 3 replicates). The nine benthic macroinvertebrate families (Baetidae, Libellulidae, Protoneuridae Chironomidae, Curbicullidae Hydropchysidae, Tubificidae, Lumbriculiade, and Naididae) were identified using PCA and regression. The cluster analysis and mean confidence intervals were used to classify water quality classes precisely. Finally, three different value scales were produced to represent the level of contamination (i.e., <0.69 as organically polluted, 0.69-0.87 as slightly organic polluted, and >0.87 as clean status). The newly developed model was validated. The results produced after validation were better than the water quality status from other studies based on the BMWP/BMWPThai score. This study concludes that the developed model can evaluate river organic contamination successfully. model can evaluate river organic contamination successfully.

INTERPRETATION OF CURRENT AND TIDAL PATTERN AT SELANGOR RIVER, KUALA SELANGOR

Abstract. Tidal data has been used to determine long-term water level alterations. Tides are high-powered and notoriously hard to ascertain. Tidal analysis and prediction need substantial study with the requisite approaches, techniques, and tools in conjunction with weather parameters and natural calamities. TOtal TIde Solution (TOTIS) software, which is rooted in harmonic analysis, is one of the most often used software in Malaysia. This study aims to interpret the current circulation and tidal pattern at the Selangor River, Kuala Selangor, Selangor Darul Ehsan. A period of one-month data is retrieved via Valeport 740 Tide Gauge from tide gauge station, whereas the current data are retrieved via Valeport Current Meter 105, which are used to analysed. The latest updated data period for the tide gauge station utilised are based on the availability of data. Therefore, tides are predicted using 33 resolved constituents for two years, starting from January 2021 until December 2022. Tidal analysis generates tidal constituents, which are then used for tidal prediction. Root Mean Square Error (RMSE) and datum offset are used to evaluate software's output. It signifies that TOTIS software is trustworthy and reliable in terms of tidal analysis and prediction accuracy. The highest river current records with high speed occur during high tide phenomenon. The output data for magnitude of river current speed are derived satisfactorily with high precision. It aids in monitoring and analyse of an appropriate method to prevent or reduce additional river erosion.

THE ENVIRONMENTAL FLOW METHOD FOR SUPPLEMENTING THE WATER NEEDED FOR THE MANAGEMENT OF SELANGOR RIVER, MALAYSIA

The shortage of water resources is one of the main problems in the world today, and water pollution and under-utilization of water resources are two factors contributing to this shortage. Appropriate supplement environmental flow can have a positive impact on dilution of pollutants, and consequently on fish habitats and the characteristics of the river channels. The purpose of this study is to determine the environmental water demand of the lower Selangor River, known as Sungai Selangor, through the Tennant Method, and then compare the data with the findings in available documents in order to ascertain the most economical and favorable supplement environmental flow method. The results of this study show that the months of November and December between the years 2009 and 2018 were the peak periods of discharge, with it being important for the discharge of these two months to meet 200% of the average annual flow needed to maintain fish habitats and channels in downstream Sungai Selangor. To meet the requirements of supplement environmental flow and improvement of water quality, it is recommended that the spillway working gate of the Sungai Kerling hydropower plant be modified so that the flow can be discharged downstream to supplement the environmental flow. Providing environmental flows for downstream would generate economic benefits and allow upstream and downstream regions to share resources.

GIS-based risk assessment of tropical surface water pollution by integrating hydrogeological and anthropogenic parameters

Surface water pollution is a huge issue worldwide that keeps growing in magnitude and complexity which leads to millions of people don’t have access to clean water resource. Numerous studies on vulnerability, hazard and risk assessment of water pollution had been conducted yet most of them only focused on one of the three risk components. Therefore, the objective of this study was to apply a geospatial approach that integrated hydrogeological and anthropogenic parameters to assess the risk of surface water pollution in Selangor River Basin, Malaysia. Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) were applied in hydrogeological vulnerability assessment. WRASTIC index was used in anthropogenic hazard assessment. The risk map showed that high-risk zones were mainly located in areas where development and agricultural activities are extensive. Conversely, low-risk zones were in areas that were mostly covered by forest with few developments, such as the upstream region. The results also revealed that high and very risk levels were dependent on soil media and presence of land use and anthropogenic activity especially agriculture, industry, and wastewater presence. The risk map also showed that developed area with high hydrogeological vulnerability would have higher risk of pollution compared to areas without any anthropogenic hazard. The risk map can assist stakeholders to identify at risk of pollution. This allows for better decision-making in integrated river basin management.

Invaders of Langat River: Introduction of varied vermiculated sailfin catfish, Pterygoplichthys disjunctivus

Globally and locally, invasive aquatic species pose a major threat towards aquatic ecosystems. Among the most successful of these aquatic invaders in Malaysian freshwater river systems is the vermiculated sailfin catfish or Pterygoplichthys disjunctivus. The study is conducted in Langat River, a subsidiary of the Selangor River basin which flows through the capital and high population density areas of the country. The impact of the species can be seen through its overpopulation and high density in the river due to the absence of natural predators and extremely high fecundity. This study provides the first report on the occurrence of introduced vermiculated sailfin catfish, P. disjunctivus, from Langat River, where the P. pardalis had been previously reported. In this study, random sampling exercises were conducted by using gill nets in a stretch of the Langat River. Out of 24 samples of Pterygoplichthys obtained, 11 were of P. pardalis. This was further confirmed by the morphometric and meristic characters as well as the patterns on the fish. Furthermore, during the sampling, we also described a new body pattern Pterygoplichthys, which does not fit both P. pardalis and P. disjunctivus entirely. The new body pattern of Pterygoplichthys, could be the result of hybridization between both species or variation patterns within the same species. However, a deeper study is necessary to be conducted to confirm this claim.

Future Outlook of Fresh Water Supply and Demand in Selangor

Water is an essential resource for the well-being of humans as well as for ecosystems. In this regard, the increasing water scarcity areas has become one of the major problems faced by humanity. In Malaysia, Selangor is considered a water-stressed area due to the increase in water demand and limited suitable fresh water resources for treatment and distribution. The increase in population as well as urbanization and industrialization made the rivers in Selangor arguably the most polluted compared to other states. These situations result in a series of unscheduled water supply interruption over the years and negatively impact the majority of consumers. Projected water demand also indicates that the existing water supplies are not sufficient in the long run, therefore, it is deemed required to study the water demand and supply gap in Selangor to ensure the current water management is sustainable for the remote future. This paper mainly discusses on the current water production from Water Treatment Plants as well as projection of water demand which also foresee the future water deficit in Selangor. The method used in this study was based on review of secondary data acquired from available published report and website, while the assessment of water demand conducted comprise of calculation of projected population, projected domestic water demand, projected total water demand and water deficit up to year 2050. According to the result obtained, the existing water demand and supply in Selangor is 4,967 MLD, meanwhile, the projection of water demand in Selangor up to year 2050 is 7,011 MLD with the projected water deficit of 2,044 MLD. The findings of this paper are essential in water resources planning and management, particularly in terms of additional raw water supply that will be required to cater to the future water demand in Selangor.

Arthropod Communities on Sonneratia caseolaris along Selangor River, Kampung Kuantan, Kuala Selangor, Malaysia

Sonneratia caseolaris commonly known as mangrove apple or Berembang in the Malay language, is a species of plant in the family Lythraceae. Area of S. caseolaris along Selangor River in Kampung Kuantan has become a natural habitat for a variety of arthropods. This study aimed to identify the species variations in arthropod communities at different selected stations along Selangor River at two different sampling times. Present study was conducted for six consecutive months (August 2010 until January 2011) at 19 selected stations along the Selangor River. Sampling was conducted once per day and night. Sweeping method by using sweep nets were used as the arthropod sampling method. Data analysis was done quantitatively to determine the composition of arthropod community. A total of 7,707 individual arthropods collected belonging to 10 different orders consisting of Coleoptera, Hymenoptera, Diptera, Neuroptera, Orthoptera, Odonata, Lepidoptera, Blattodea, Mantodea and Araneae. A total of 4,563 arthropod individuals were sampled at night, which was more than the daytime (3,144 individuals), with Station 17 recorded the highest arthropod individual out of the 19 sampling sites. During the night, the firefly, that belongs to the Lampyridae family showed the highest arthropod composition. The presence of arthropod biodiversity along the Selangor River reveals that the S. caseolaris area is important in maintaining a diverse community of fireflies and other arthropods for conservation purposes.

Water quality assessment and pollution threat to safe water supply for three river basins in Malaysia

Pollution in raw water poses increasing threats to safe water supply in many developing countries. Therefore, a comprehensive water quality assessment is essential to provide various stakeholders the information to deal with this problem. This study applies chemometrics to interpret a recent 10-year water quality data from three major river basins (Selangor River basin, Langat River basin, and Klang River basin) frequented by water supply disruptions in Selangor, Malaysia. We present the application of selected chemometrics approaches, namely agglomerative hierarchical cluster analysis, principal component analysis, factor analysis and Man-Kendall trend analysis. The results showed three spatial groups of monitoring stations with similar land use practices and pollution characteristics. Besides spatial differences, periodic variations were observed when similar pollutants exhibited different pollution loads during rainy and dry periods. We found that nitrogen species, total suspended solids, and dissolved solids represented the major pollution loads in the studied basins. The results further confirmed a significant increasing trend in ammonia pollution. Our study demonstrates how ammonia pollutant is likely to pose a threat to water supply and highlights the vulnerability of Selangor's water resource system to water pollution. The results of this study could facilitate decision making towards more holistic strategies, specifically, incorporating ammonia treatment facilities into the conventional water treatment plant will help achieve smooth water supply operations.

Real-Time and Intelligent Flood Forecasting Using UAV-Assisted Wireless Sensor Network

The Wireless Sensor Network (WSN) is a promising technology that could be used to monitor rivers’ water levels for early warning flood detection in the 5G context. However, during a flood, sensor nodes may be washed up or become faulty, which seriously affects network connectivity. To address this issue, Unmanned Aerial Vehicles (UAVs) could be integrated with WSN as routers or data mules to provide reliable data collection and flood prediction. In light of this, we propose a fault-tolerant multi-level framework comprised of a WSN and a UAV to monitor river levels. The framework is capable to provide seamless data collection by handling the disconnections caused by the failed nodes during a flood. Besides, an algorithm hybridized with Group Method Data Handling (GMDH) and Particle Swarm Optimization (PSO) is proposed to predict forthcoming floods in an intelligent collaborative environment. The proposed water-level prediction model is trained based on the real dataset obtained from the Selangor River in Malaysia. The performance of the work in comparison with other models has been also evaluated and numerical results based on different metrics such as coefficient of determination (), correlation coefficient (), Root Mean Square Error (), Mean Absolute Percentage Error (), and are provided.