Flood flow simulations and return period calculation for the Kota Tinggi watershed, Malaysia

Abdullah, Jazuri; Muhammad, Nur Shazwani; Juliën, Pierre Y.; Ariffin, Junaidah; Shafie, Atikah

doi:10.1111/jfr3.12256

Cited by 30 publications

(7 citation statements)

References 50 publications

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“…2), four statistical analyses were also used to evaluate the model performance, namely, the Nash-Sutcliffe Efficiency Coefficient (NSEC), Mean Absolute Error (MAE), Determination Coefficient (R2) and Discrepancies Ratio (DR) [10]. NSEC value of 1 indicates that the model is able to estimate the flow as good as the observed data, while the efficiency value of less than zero shows that the simulated result is less than the actual mean [12][13]. The value R2 approaching the value of 1 indicates that the model is more in line with the observed data.…”

Section: Hydraulic Simulation Results -Calibration and Validationmentioning

confidence: 99%

Chlorine Decay Simulation in Water Distribution System Using EPANET

Muhammad

Shin²,

Abdullah

2021

IJIE

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Chlorine is used as a disinfectant in the water treatment process so that treated water is delivered safely to consumers. However, chlorine concentration decays when water flows from the treatment plant to the supply point, due to the reaction with natural organic matter and the inner surface of the pipe. Low chlorine concentration may encourage bacteria re-growth, while high chlorine concentration can result in the formation of harmful chemical components. Therefore, this study aims to simulate the complex process of chlorine decay using EPANET. This exercise enables the determination the chlorine concentration dosage required to maintain the desired requirement given by the World Health Organization (WHO) and the Ministry of Health, Malaysia (MOH). A successful model with an extended period of simulations of 72 hours enable the mapping of spatial and temporal variations of flow and residue chlorine concentrations at all links and nodes. Constant chlorine dosage of 3.96 mg/l at node R1 has successfully satisfy the requirement given by WHO and MOH. The residue chlorine concentrations at the nodes and links in the water distribution system also depends on the water usage at node 5, the size of service reservoir and service tank and distance from the reservoir.

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Section: Hydraulic Simulation Results -Calibration and Validationmentioning

confidence: 99%

Chlorine Decay Simulation in Water Distribution System Using EPANET

Muhammad

Shin²,

Abdullah

2021

IJIE

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“…Kota Tinggi consist of large watershed area and experience high amount of rainfall with annual average rainfall of 2470 mm. The study that are related to worst flood that occurred over large watershed due to the monsoon climates are poorly known and conducting comprehensive research is helpful to give an insight about climatic and hydrologic conditions of an area [12]. There are two (2) selected rainfall station at Kota Tinggi, Johor that are utilized to perform this research and to collect the rainfall data needed.…”

Section: Study Area and Precipitation Datamentioning

confidence: 99%

Climate Change Assessment on Flood Occurrence in Kota Tinggi, Johor

Anuar

Rahmat

2022

JAESRR

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Flood is associated with the climatic change where the climate variable has detrimental impact on hydrologic cycle. Johor is among the affected states by flood catastrophe for almost every year. Over the year, Johor has experienced increasing amount of rainfall. However, studies on future rainfall pattern in Johor are still quite limited. Thus, this study was carried out to identify climate change impacts by projecting rainfall data using Statistical Downscaling Model (SDSM) and predicting flood events utilizing the Standardised Precipitation Index (SPI). Through SDSM, the rainfall data was projected in corresponding with General Circulation Models (GCM) predictor under three different representative concentration pathway (RCP) of RCP2.6, RCP4.5 and RCP8.5 that consider different emission level in future. Future observation in the upcoming 30 years for both studied stations at Kota Tinggi, Johor recorded increasing trend in the projected mean annual rainfall under three scenarios where the highest change in projection was +12.2% under RCP8.5 at Ladang Telok Sengat station. From SPI analysis, it is predicted that there will be frequent occurrence of flooding in the upcoming 30 years due to more positive SPI values (> 1) indicated by the studied stations. From the study, the authorities can come up with better mitigation plan to supervise the flood event in the future.

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“…The NSEC is commonly used in hydrological modelling, e.g., runoff simulation and floods [19,20,41]. This performance indicator was developed by ref.…”

Section: Nash-sutcliffe Efficiency Coefficient (Nsec)mentioning

confidence: 99%

“…However, further analysis on the efficiency and accuracy of the calibrated model has been less covered and discussed, especially for water distribution network modelling. The Nash-Sutcliffe efficiency coefficient (NSEC) is found to be the best statistical approach for model performance evaluation especially in hydrological modelling [19][20][21][22]. Refs.…”

Section: Introductionmentioning

confidence: 99%

Model Performance Indicator of Aging Pipes in a Domestic Water Supply Distribution Network

Rahman

Muhammad

Abdullah

et al. 2019

Water

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Aging pipes in the domestic water distribution network have the potential to decrease the quality and quantity of the treated water supplied to the consumers. Therefore, a calibrated water distribution model is helpful to monitor and understand the behaviour of a real water distribution network. However, a comprehensive performance indicator and an integrated method to assess the efficiency of model performance have not been well established in the literature. This study developed a methodology for a model calibration exercise, with consideration of two uncertainty parameters, i.e., Hazen–Williams roughness coefficient of the pipes and Non-Revenue Water (NRW) in each nodal demand. Following this, a statistical color-coded performance indicator was established, based on the Nash–Sutcliffe Efficiency Coefficient (NSEC), the coefficient of determination (R2), the correlation coefficient (r), and the Mean Absolute Error (MAE). The accuracy of the calibrated model was measured by Discrepancy Ratio (DR) analysis. This study concluded that the model performed well when NRW was added to the nodal demand in zone(s) with suspected water loss activities. The suggested Hazen–Williams roughness coefficient for PVC pipes was between 130 and 140 for pipes aged more than 20 years. The threshold error value to determine the accuracy of the simulated model was proposed to be between –0.05 and 0.05.

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Flood flow simulations and return period calculation for the Kota Tinggi watershed, Malaysia

Cited by 30 publications

References 50 publications

Chlorine Decay Simulation in Water Distribution System Using EPANET

Chlorine Decay Simulation in Water Distribution System Using EPANET

Climate Change Assessment on Flood Occurrence in Kota Tinggi, Johor

Model Performance Indicator of Aging Pipes in a Domestic Water Supply Distribution Network

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