National Hydraulic Research Institute of Malaysia
National Hydraulic Research Institute of Malaysia
Amin M.Z.M.,National Hydraulic Research Institute of Malaysia |
Shaaban A.J.,National Hydraulic Research Institute of Malaysia |
Ercan A.,University of California Davis |
Ishida K.,University of California Davis |
And 2 more authors.
Science of the Total Environment | Year: 2017
Impacts of climate change on the hydrologic processes under future climate change conditions were assessed over Muda and Dungun watersheds of Peninsular Malaysia by means of a coupled regional climate and physically-based hydrology model utilizing an ensemble of future climate change projections. An ensemble of 15 different future climate realizations from coarse resolution global climate models’ (GCMs) projections for the 21st century was dynamically downscaled to 6 km resolution over Peninsular Malaysia by a regional climate model, which was then coupled with the watershed hydrology model WEHY through the atmospheric boundary layer over Muda and Dungun watersheds. Hydrologic simulations were carried out at hourly increments and at hillslope-scale in order to assess the impacts of climate change on the water balances and flooding conditions in the 21st century. The coupled regional climate and hydrology model was simulated for a duration of 90 years for each of the 15 realizations. It is demonstrated that the increase in mean monthly flows due to the impact of expected climate change during 2040–2100 is statistically significant from April to May and from July to October at Muda watershed. Also, the increase in mean monthly flows is shown to be significant in November during 2030–2070 and from November to December during 2070–2100 at Dungun watershed. In other words, the impact of the expected climate change will be significant during the northeast and southwest monsoon seasons at Muda watershed and during the northeast monsoon season at Dungun watershed. Furthermore, the flood frequency analyses for both watersheds indicated an overall increasing trend in the second half of the 21st century. © 2016 Elsevier B.V.
Sheikhy Narany T.,University Putra Malaysia |
Aris A.Z.,University Putra Malaysia |
Sefie A.,National Hydraulic Research Institute of Malaysia |
Keesstra S.,Wageningen University |
Keesstra S.,University of Newcastle
Science of the Total Environment | Year: 2017
The conversions of forests and grass land to urban and farmland has exerted significant changes on terrestrial ecosystems. However, quantifying how these changes can affect the quality of water resources is still a challenge for hydrologists. Nitrate concentrations can be applied as an indicator to trace the link between land use changes and groundwater quality due to their solubility and easy transport from their source to the groundwater. In this study, 25 year records (from 1989 to 2014) of nitrate concentrations are applied to show the impact of land use changes on the quality of groundwater in Northern Kelantan, Malaysia, where large scale deforestation in recent decades has occurred. The results from the integration of time series analysis and geospatial modelling revealed that nitrate (NO3-N) concentrations significantly increased with approximately 8.1% and 3.89% annually in agricultural and residential wells, respectively, over 25 years. In 1989 only 1% of the total area had a nitrate value greater than 10 mg/L; and this value increased sharply to 48% by 2014. The significant increase in nitrate was only observed in a shallow aquifer with a 3.74% annual nitrate increase. Based on the result of the Autoregressive Integrated Moving Average (ARIMA) model the nitrate contamination is expected to continue to rise by about 2.64% and 3.9% annually until 2030 in agricultural and residential areas. The present study develops techniques for detecting and predicting the impact of land use changes on environmental parameters as an essential step in land and water resource management strategy development. © 2017 Elsevier B.V.
Ahmad Z.,Universiti Sains Malaysia |
Rahim N.A.,National Hydraulic Research Institute of Malaysia |
Bahadori A.,Southern Cross University of Australia |
Zhang J.,Northumbria University
IIUM Engineering Journal | Year: 2017
Air quality monitoring and forecasting tools are necessary for the purpose of taking precautionary measures against air pollution, such as reducing the effect of a predicted air pollution peak on the surrounding population and ecosystem. In this study a single Feed-forward Artificial Neural Network (FANN) is shown to be able to predict the Air Pollution Index (API) with a Mean Squared Error (MSE) and coefficient determination, R2, of 0.1856 and 0.7950 respectively. However, due to the non-robust nature of single FANN, a selective combination of Multiple Neural Networks (MNN) is introduced using backward elimination and a forward selection method. The results show that both selective combination methods can improve the robustness and performance of the API prediction with the MSE and R2 of 0.1614 and 0.8210 respectively. This clearly shows that it is possible to reduce the number of networks combined in MNN for API prediction, without losses of any information in terms of the performance of the final API prediction model.
Latiff M.F.P.M.,University Technology of MARA |
Abustan I.,Universiti Sains Malaysia |
Ahmad M.A.,Universiti Sains Malaysia |
Yahaya N.K.E.M.,National Hydraulic Research Institute of Malaysia |
Khalid A.M.,University Technology of MARA
AIP Conference Proceedings | Year: 2016
This study investigates the potential use of agricultural waste corncob (C) that available in Malaysia, as the precursor for the preparation of activated carbon which can be applied for the removal of heavy metal, which is Cu(II) from aqueous solution. The experimental design results revealed that CO2 activation temperature, CO2 activation time and KOH impregnation ratio (IR) were important factors influencing the activated carbons yields and adsorption performance for Cu(II). The optimum conditions obtained for preparing the activated carbons from the selected precursors for CO2 activation temperature, CO2 activation time and IR were 797°C, 3.0 h and 3.5 respectively. © 2016 Author(s).
Ercan A.,University of California at Davis |
Bin Mohamad M.F.,National Hydraulic Research Institute of Malaysia |
Kavvas M.L.,University of California at Davis
Hydrological Processes | Year: 2013
The sea level change along the Peninsular Malaysia and Sabah-Sarawak coastlines for the 21st century is investigated along the coastal areas of Peninsular Malaysia and Sabah-Sarawak because of the expected climate change during the 21st century. The spatial variation of the sea level change is estimated by assimilating the global mean sea level projections from the Atmosphere-Ocean coupled Global Climate Model/General Circulation Model (AOGCM) simulations to the satellite altimeter observations along the subject coastlines. Using the assimilated AOGCM projections, the sea level around the Peninsular Malaysia coastline is projected to rise with a mean in the range of 0.066 to 0.141m in 2040 and 0.253m to 0.517m in 2100. Using the assimilated AOGCM projections, the sea level around Sabah-Sarawak coastlines is projected to rise with a mean in the range of 0.115m to 0.291m in 2040 and 0.432m to 1.064m in 2100. The highest sea level rise occurs at the northeast and northwest regions in Peninsular Malaysia and at north and east sectors of Sabah in Sabah-Sarawak coastline. © 2012 John Wiley & Sons, Ltd..
PubMed | National Hydraulic Research Institute of Malaysia, K water Institute and University of California at Davis
Type: | Journal: The Science of the total environment | Year: 2016
Impacts of climate change on the hydrologic processes under future climate change conditions were assessed over Muda and Dungun watersheds of Peninsular Malaysia by means of a coupled regional climate and physically-based hydrology model utilizing an ensemble of future climate change projections. An ensemble of 15 different future climate realizations from coarse resolution global climate models (GCMs) projections for the 21st century was dynamically downscaled to 6km resolution over Peninsular Malaysia by a regional climate model, which was then coupled with the watershed hydrology model WEHY through the atmospheric boundary layer over Muda and Dungun watersheds. Hydrologic simulations were carried out at hourly increments and at hillslope-scale in order to assess the impacts of climate change on the water balances and flooding conditions in the 21st century. The coupled regional climate and hydrology model was simulated for a duration of 90years for each of the 15 realizations. It is demonstrated that the increase in mean monthly flows due to the impact of expected climate change during 2040-2100 is statistically significant from April to May and from July to October at Muda watershed. Also, the increase in mean monthly flows is shown to be significant in November during 2030-2070 and from November to December during 2070-2100 at Dungun watershed. In other words, the impact of the expected climate change will be significant during the northeast and southwest monsoon seasons at Muda watershed and during the northeast monsoon season at Dungun watershed. Furthermore, the flood frequency analyses for both watersheds indicated an overall increasing trend in the second half of the 21st century.
Shamsuddin M.K.N.,National Hydraulic Research Institute of Malaysia |
Shamsuddin M.K.N.,University Putra Malaysia |
Sulaiman W.N.A.,University Putra Malaysia |
Suratman S.,National Hydraulic Research Institute of Malaysia |
And 2 more authors.
Hydrogeology Journal | Year: 2014
Bank infiltration (BI) is one of the solutions to providing raw water for public supply in tropical countries. This study in Malaysia explores the use of BI to supplement a polluted surface-water resource with groundwater. Three major factors were investigated: (1) contribution of surface water through BI to the resulting abstraction, (2) input of local groundwater, and (3) water-quality characteristics of the resulting water supply. A geophysical method was employed to define the subsurface geology and hydrogeology, and isotope techniques were performed to identify the source of groundwater recharge and the interaction between surface water and groundwater. The physicochemical and microbiological parameters of the local surface-water bodies and groundwater were analyzed before and during water abstraction. Extracted water revealed a 5-98 % decrease in turbidity, as well as reductions in HCO3 -, Cl-, SO4 2-, NO3 -, Ca2+, Al3+ and As concentrations compared with those of Langat River water. In addition, amounts of E. coli, total coliform and Giardia were significantly reduced (99.9 %). However, water samples from test wells during pumping showed high concentrations of Fe2+ and Mn2+. Pumping test results indicate that the two wells used in the study were able to sustain yields. © 2014 Springer-Verlag Berlin Heidelberg.
Abdullah M.F.,National Hydraulic Research Institute of Malaysia |
Ahmad K.,National University of Malaysia
Proceedings - 5th International Conference on Electrical Engineering and Informatics: Bridging the Knowledge between Academic, Industry, and Community, ICEEI 2015 | Year: 2015
Business Intelligence plays an important role in the organization for collecting, integrating, analyzing and transforming data to be useful for effective decision making process. Nowadays, organizations are flooded with various kinds of unstructured data such as e-mail, images, reports, maps, charts, publications. An effective and efficient business model of these data could help in decision making. Currently, there is no study done on the business intelligence model for managing unstructured data that can fulfil the organization needs. Therefore, the purpose of this paper is to improve the organization's business intelligence process through the exploitation of unstructured data that is owned by the organization. In this study, unstructured data are classified, enriched and complemented with diversity of data through the process of creating metadata for each unstructured data. Four main processes are proposed to transform unstructured data to structured data which are extraction, classification, storage and mapping of data classes. Each process and its activities are combined to produce an effective and efficient business intelligence model for unstructured data management. This model helps in generating new data and information that is more comprehensive and collective to help business intelligence through advanced analysis, decision-making process and planning new research areas. Output from this study is to make unstructured data as renewable assets that is easily accessible and used as a reference and foundation in business intelligence and decision making process. © 2015 IEEE.
Azhary W.A.H.W.,National Hydraulic Research Institute of Malaysia |
Awang N.A.,National Hydraulic Research Institute of Malaysia |
Hamid M.R.A.,National Hydraulic Research Institute of Malaysia
IOP Conference Series: Materials Science and Engineering | Year: 2016
KerachutBeach is a beautiful beach in Penang National Park (PNP). However this beach is categorisedas one of dangerous beach for swimming activities in Malaysia due to the drowning incidents reported almost every year. The steep beach slope and rip current were among the factors that lead to this incident. Using bathymetry profile, current, tidal and sediment data collected at site incorporated with UKMO wave data analysis,the hydrodynamic pattern was simulated using Mike 21 modelling software. Result from the model showed the evidence of rip current existence along the coastline. It showed that this rip current eventsoccurred during spring tide phase when the flow change from Flood to Ebb. During this period, the current tend to move parallel to the shoreline with maximum speed of 0.3m/s which is capable to swipe away a swimmer. The bathymetry profile at Kerachutis very steep and dangerous to swimmers since there is a 4 meter sudden plunge just meters away from the shoreline. © Published under licence by IOP Publishing Ltd.
Sharip Z.,University of Western Australia |
Sharip Z.,National Hydraulic Research Institute of Malaysia |
Schooler S.S.,University of Wisconsin-Superior |
Hipsey M.R.,University of Western Australia |
Hobbs R.J.,University of Western Australia
Biological Invasions | Year: 2012
In this study we: (1) present a quantitative spatial analysis of the macrophyte communities in Lake Chini with a focus on the biogeographical distributions of the native Nelumbo nucifera and the invasive Cabomba furcata; (2) examine the environmental changes that affect plant community composition; and (3) outline a conceptual model of the variation of ecological processes that shape the macrophyte communities. Plant species cover, biomass of C. furcata and N. nucifera, and water quality and environmental variables were measured before and after monsoonal floods in September 2009 and April 2010. Permutational multivariate analysis was used to examine the significance of the invasion of C. furcata at different spatial scales. Relationships between plant species cover and environmental variables before and after flooding were examined using principal coordinates analysis and non-parametric multivariate multiple regressions. Our findings suggest that (1) Variation in plant communities was significant at the lake scale and the distribution of plant species changed after annual floods. (2) Invasion by C. furcata significantly affected the overall plant community composition. (3) C. furcata biomass increased after the monsoonal season, which indicates that C. furcata is adapted to flooding events and that it is becoming increasingly abundant. (4) In addition to the strong monsoonal effect, total depth, nutrient concentration, and sediment type were important environmental variables that significantly affected plant community composition. The macrophyte community in Lake Chini is highly dynamic. The spatial and temporal plant community dynamics are associated with flood regime, water quality, and substrate. Human-induced changes in these parameters are likely shifting the macrophyte dominance from floating-leaved to submerged species. © 2011 Springer Science+Business Media B.V.