Now showing 1 - 7 of 7
  • Publication
    Analysing impact of climate change on hydrological trend in Kelantan river basin using HEC-HMS coupled with SDSM
    (Springer, 2023)
    Muhammad Zahran Syahmi Armain
    ;
    ;
    Sobri Harun
    ;
    Mohd Remy Rozainy Mohd Arif Zainol
    ;
    Ain Nihla Kamarudzaman
    ;
    Climate change dramatically alters many hydrologic systems, which affects the availability of water and leads to runoff and river discharge. This study assessed the effects of the future scenario of climate change on the monthly river discharge of the Kelantan River Basin, Malaysia. Statistical DownScaling model (SDSM) was used to downscale the rainfall from large climate variables of the second-generation Canadian Earth System Model (CanESM2) under the Representative Concentration Pathways of 8.5 (RCP 8.5) and project future river discharge using the Hydrologic Modeling System (HEC-HMS). From this study, the monthly rainfall and river discharge over the Kelantan River basin will be significantly reduced in the future by 30 and 50% compared to the current period.
      4  7
  • Publication
    Assessing Hydrological Response in the Timah-Tasoh Reservoir Sub-Catchments: Calibration and Validation using the HEC-HMS Model
    ( 2024)
    N A S Nordin
    ;
    ;
    N M Noor
    ;
    Ain Nihla Kamarudzaman
    ;
    A S A Ahmadni
    Abstract Hydrological modelling is a tool that is frequently used for assessing the hydrological response of a basin as a result of precipitation. It is also a vital component as water resources and environmental planning management. The study deals with calibrating and validating the hydrological response in the sub-catchments of the Timah-Tasoh reservoir using the hydrological model named Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS). This study uses the SCS Curve Number, the SCS Unit Hydrograph, the constant monthly baseflow, and lag routing for the model development. The model was simulated for ten (10) years for calibration and nine (9) years for validation. The model calibration and validation efficiency were assessed using the coefficient of correlation (R). The findings show that the HEC-HMS model performs satisfactorily in simulating the observed daily inflow series, with the R-value of 0.4902-0.5139 during calibration and 0.5047-0.5559 during validation process. Thus, the result obtained from this study can be used as a preliminary development of hydrological modelling of the catchment of the Timah-Tasoh reservoir and can be used for extend application such as water inflow forecasting, impact of land use to the reservoir and others.
      2  19
  • Publication
    Distribution and Characteristic Sediment Material of Watershed Deli River-Sumatera, Indonesia
    Abstract Rivers are a source of surface water and bring benefits to human life. River water quality changes along with the development of the river environment which is influenced by various activities and human life. Deli River is one of the rivers used by the people of Medan-North Sumatra as a provider of clean water and various other daily activities and is also used as a transportation route for fishermen. This study aims to determine the flooding conditions that often occur in the Deli River, this is caused by the shallowness and narrowness of the river body. In this study, the quantitative method was taking sediment samples at several points along the river starting from upstream, middle, and downstream with research time on 7 July 2023. The results obtained from this study were river sediment material along the Deli River from upstream to downstream generally has a grain size of 65% sand, a grain size of 26% clay, a grain size of silt 6.3%, and a grain size of gravel 3.7%. The upstream sediments are dominated by sand-sized sediments and in the middle (between the upstream and downstream) the sediments are dominated by clay-sand-sized sediments, while the downstream sediments are predominantly sandy loam. The flooding of the Deli River is caused by the reduced capacity of the river, high intensity of rainfall in the upper reaches, and narrowing of the river and high sediment deposits in the middle to lower reaches so flooding often occurs along the Deli River.
      2  30
  • Publication
    Comparison of artificial neural network and support vector machine for long-term runoff simulation
    (IOP Publishing, 2020) ;
    S Z Rosdi
    ;
    Kamarudzaman, Ain Nihla
    ;
    ;
    Simulation of runoff from a river catchment is a very difficult task and it involves a lot of data which need to be considered. However, the modelling is very essential to forecast the patterns of future runoff by observing and analysing previous patterns of runoff, based on the rainfall. This study presents the evaluation of rainfall-runoff modelling for the long-term runoff series using Artificial Neural Network (ANN) and Support Vector Machine (SVM). Both models are trained and validated using the data series of current and nine (9) antecedent rainfall. During the validation, the SVM model is better in the performance as compared the ANN model, with the R and RMSE values are 0.529-0.711 and 14.27-52.55 mm, respectively. However, the SVM model is underestimated for the peak discharge. Both models have the ability to derive the relationship between the inputs and outputs of the rainfall-runoff process.
      5  18
  • Publication
    Spatial and temporal analysis of Particulate Matter (PM10) in urban-industrial environment during episodic haze events in Malaysia
    (Thai Society of Higher Education Institutes on Environment, 2023)
    Izzati Amani Mohd Jafri
    ;
    ;
    Nur Alis Addiena A. Rahim
    ;
    Ahmad Zia Ul-Saufie
    ;
    ;
    György Deak
    Haze episode in Malaysia typically takes place during the dry monsoon season. As a result, high concentration of atmospheric particles was recorded primarily brought by transboundary air pollution from the neighbour country. Therefore, this study aims to evaluate and compare the level of particulate matter (PM10) at urban-industrial areas during the episodic haze episodes in Malaysia. Hourly PM10 concentration with the concentration of gaseous air pollutants such as NOx, NO2, SO2, CO and O3 and meteorological parameters (relative humidity, temperature, wind speed) at urban-industrial areas namely Shah Alam (Selangor), Nilai (Negeri Sembilan), Bukit Rambai (Melaka) and Larkin (Johor), during the haze episode in 1997, 2005, 2013 and 2015 were used for analysis. In this study, spatio-temporal and correlation analysis were used to provide an overview of the distribution pattern and examine the relationships between the gaseous air pollutants and meteorological parameters with PM10 concentration. From the descriptive statistics, it was observed that PM10 level for all study areas were skewed to the right (> + 1) indicating occurrences of extreme events. A significant peak of PM10 concentration for each year of haze events were observed to be started in June or during the southwest monsoon to the inter monsoon in October. The occurrence, duration and impact of 1997 haze was detected to be identical to the 2015 haze event that reached its peak in October. From the correlation analysis, PM10 concentration were strongly correlated to the CO concentration (r > 0.5) during High Particulate Event (HPE). Very weak relationship of PM10 level with meteorological parameters (r < 0.3) were observed. Interestingly, O3 level shows very strong correlation with the meteorological parameters during HPE. The findings provide comprehensive evaluation on PM10 level during the historic haze episodes, thus can help the authorities in developing policies and guidelines to effectively monitor and reduce the negative impact of haze events.
  • Publication
    Modeling and visualization of the changes of flow in the modular paver using ANSYS FLUENT
    (IOP Publishing, 2023) ; ;
    Ain Nihla Kamarudzaman
    ;
    ; ;
    Muaz Mohd Zaini Makhtar
    ;
    Increasing quantity of stormwater runoff is natural but problematic consequences of urbanization. In addressing the issue, the porous pavement usage with modular installation system has been the new alternative being experimented instead of the traditional impervious asphalt and concrete pavers. The effectiveness of porous pavement depends upon the media materials used. This study examined the potentials of an invented surface fill arrangement to be used in conjunction with the hexagonal modular system where the media tested consists of granular activated carbon (GAC), sand and zeolite. The resulting optimum bed heights of 5 cm, 5 cm and 0 cm respectively for the GAC, sand and zeolite, corroborated with the outcome of employing the optimization function, thus validating the reliability of the given arrangement. Modeling using CFD ANSYS FLUENT software and visualizing the changes in the hexagonal module filled with GAC and sand of 5 cm thickness each resulted in a flow velocity of 3.5 x 10-5 m/s while a physical experiment on the fixed filter bed media consisting of the two materials gave an unsaturated velocity of 3.08 x 10-5 m/s. The 12 % difference between the experimental and simulated velocities was considered acceptable. The results showed that GAC and sand can be used as the media for the modular paver system that treats stormwater for heavy metals contamination while serving as a practical porous pavement alternative.
  • Publication
    Preliminary study on flood simulation using the HEC-HMS model for Muda River, Malaysia
    (IOP Publishing, 2023) ;
    Najiha H Mohd Razali
    ;
    Ain Nihla Kamarudzaman
    ;
    ;
    Nor Aisyah Syafiqah Nordin
    Flooding poses a severe threat to human beings and causes significant damage to property, infrastructure, and agricultural production. The flood also has severe consequences for socio-economic activities and can lead to the loss of human life. One of the significant factors that cause the flood is rapid development, especially in the floodplain area. This study estimates the flood discharge along the Muda River, Malaysia using Hydrological Modelling System (HEC-HMS). The finding shows that the HEC-HMS model performed well during the validation period, in which the coefficient determination (R2) between observed and simulated discharge during the validation process ranges from 0.51-0.84. In terms of design flood, the model simulated the peak flow with 1247-1448.8 m3/s and 1798.5-3662.5 m3/s for 50 and 100-year ARIs, respectively. The results obtained from this study can be used as fundamental data for advanced studies of flood control and management for better sustainable flood risk management.