The Journal of The Institution of Engineers, Malaysia, 2016
Flood estimations based on itting the frequency of occurrence of annual peak discharges using the... more Flood estimations based on itting the frequency of occurrence of annual peak discharges using the Log-Pearson Type 3 distribution are commonly used but they are sensitive to the skew coeficients of the gauging stations. The estimation accuracy can be improved by using a weighted average population skew coeficient calculated from the sample station skew and the generalised unbiased skew. The U.S. Water Resources Council (WRC) has documented guidelines for estimating the generalised skew coeficients and published a map of generalised skew values for the United States. The map shows isolines of skew coeficient values and the average skew coeficient for each 1-degree quadrangle of latitude and longitude for the United States. Following the WRC guidelines, many of the state authorities in the US have developed the generalised skew coeficients separately on a state/regional basis. In Malaysia, the Log Pearson Type 3 distribution has been widely used for lood peakestimation but there are n...
The Journal of The Institution of Engineers, Malaysia, 2018
Temporal and spatial variations of a flood hydrograph moving through a river reach can be simulat... more Temporal and spatial variations of a flood hydrograph moving through a river reach can be simulated using flood routing tools such as hydrodynamic, hydrological and the ANN (Artificial Neural Networks) models. The ANN models have emerged as viable tools in flood routing and are widely adopted for this purpose. The aim of this study is to make an objective comparison of these two flood routing models to evaluate their individual performance. Four flood events recorded for Klang river at Kuala Lumpur in the period October 1973 to December 1974 for stations at Leboh Pasar and Sulaiman Bridge which are 950m apart were used for this study. The statistical performance of the models is assessed using criteria such as peak flow, root mean square error, mean absolute error and Nash –sutcliffe coefficient. Results from calibration runs for the 02/05/1974 flood event show that the MAE, RMSE and NAE for ANN and Muskingum models are 0.75,1.24,0.9917 and 1.1,1.3, 0.992 respectively. The performan...
The Journal of The Institution of Engineers, Malaysia, 2018
Rainfall temporal patterns are needed as inputs for hydrologic models such as unit hydrograph or ... more Rainfall temporal patterns are needed as inputs for hydrologic models such as unit hydrograph or runoff routing method used in the derivation of flood hydrographs. The patterns adopted can have a major effect on the resulting flood computed. Short and long duration rainfall data are both required for different sizes of catchments to determine and locate the flood producing critical storms in flood estimation. Design temporal patterns with different durations are therefore also required for distributing the storm rainfall in flood calculations. Patterns for a large number of durations with reasonably short time intervals are needed by designers to reduce the need for interpolation and to maintain the accuracy in obtaining the peak of the hydrograph. In this study, pluviograph data for the Upper Klang Catchment with records of over 30 years are used to derive temporal patterns for 20 standard durations as per ARR87. Rainfall temporal patterns for the upper Klang were derived for rainf...
The Journal of The Institution of Engineers, Malaysia, 2018
In this Study, the Muskingum and Lag river routing models were used to estimate the routing coeff... more In this Study, the Muskingum and Lag river routing models were used to estimate the routing coefficients of Klang river using flood records of gauging stations at Leboh Pasar and Sulaiman Bridge, for a river reach of 900m between the two gauging stations. Recorded inflow hydrographs at Leboh Pasar and outflow hydrographs at Suilaman Bridge were used to calibrate and validate the Muskingum and Lag routing models. Best fit routing parameters for the models were derived using the optimization module of HEC-HMS, and the average parameters obtained were used to validate the routing models using different sets of flood events. The outflow hydrographs at Sulaiman Bridge derived from routing models were used to compare with the observed hydrographs by plotting the hydrographs for visual inspections. The ability to produce the observed flow at the Sulaiman Bridge by the routing models were also assessed statistically by calculating the goodness of fit indices from the routed and observed hyd...
A set of quality control streamflow data is always required in the planning, design and managemen... more A set of quality control streamflow data is always required in the planning, design and management of water resources projects. Although every effort has been made by the authority in the collection of complete and continuous hydrological data such as rainfall and streamflow, gaps and incomplete data sets with inadequate length are always encountered, as is always the case. These can be due to faulty field instruments, the occurrence of natural disasters and other reasons. Over the years, various techniques have been developed to infill the missing data, especially the streamflow data. These techniques include regression analysis ,rainfall runoff modelling and the use of artificial neural networks(ANN) data driven models. In this study, the HEC-HMS model is used to simulate long term daily streamflow of Sg Melaka. The process involved using recorded flow and rainfall data of 1989-1992 to calibrate the model and the model validation using records of 1985-1986. Results show that the m...
2012 International Conference on Advanced Computer Science Applications and Technologies (ACSAT), 2012
ABSTRACT With the introduction of World Wide Web, users are able to connect and interact with eac... more ABSTRACT With the introduction of World Wide Web, users are able to connect and interact with each other anywhere in this world easily. However, elderly users may not be familiar with these technologies, some are even unable to cope with the rapid changes of World Wide Web. In fact, they are slow and unfamiliar with the latest trends and technology. This paper aims at addressing the problem of the gap between elderly users and the rapid changes of Internet Technologies. We use different techniques of user centred design in order to abstract design requirement for elderly users. These techniques help to gather the necessary user requirements from the elderly users. We apply these techniques to a simple case study - Web Site Design. We develop a combination of low-fidelity prototype and high-fidelity prototype to get the different perspectives of the elderly users for establishing usability requirement.
The Journal of The Institution of Engineers, Malaysia, 2016
Flood estimations based on itting the frequency of occurrence of annual peak discharges using the... more Flood estimations based on itting the frequency of occurrence of annual peak discharges using the Log-Pearson Type 3 distribution are commonly used but they are sensitive to the skew coeficients of the gauging stations. The estimation accuracy can be improved by using a weighted average population skew coeficient calculated from the sample station skew and the generalised unbiased skew. The U.S. Water Resources Council (WRC) has documented guidelines for estimating the generalised skew coeficients and published a map of generalised skew values for the United States. The map shows isolines of skew coeficient values and the average skew coeficient for each 1-degree quadrangle of latitude and longitude for the United States. Following the WRC guidelines, many of the state authorities in the US have developed the generalised skew coeficients separately on a state/regional basis. In Malaysia, the Log Pearson Type 3 distribution has been widely used for lood peakestimation but there are n...
The Journal of The Institution of Engineers, Malaysia, 2018
Temporal and spatial variations of a flood hydrograph moving through a river reach can be simulat... more Temporal and spatial variations of a flood hydrograph moving through a river reach can be simulated using flood routing tools such as hydrodynamic, hydrological and the ANN (Artificial Neural Networks) models. The ANN models have emerged as viable tools in flood routing and are widely adopted for this purpose. The aim of this study is to make an objective comparison of these two flood routing models to evaluate their individual performance. Four flood events recorded for Klang river at Kuala Lumpur in the period October 1973 to December 1974 for stations at Leboh Pasar and Sulaiman Bridge which are 950m apart were used for this study. The statistical performance of the models is assessed using criteria such as peak flow, root mean square error, mean absolute error and Nash –sutcliffe coefficient. Results from calibration runs for the 02/05/1974 flood event show that the MAE, RMSE and NAE for ANN and Muskingum models are 0.75,1.24,0.9917 and 1.1,1.3, 0.992 respectively. The performan...
The Journal of The Institution of Engineers, Malaysia, 2018
Rainfall temporal patterns are needed as inputs for hydrologic models such as unit hydrograph or ... more Rainfall temporal patterns are needed as inputs for hydrologic models such as unit hydrograph or runoff routing method used in the derivation of flood hydrographs. The patterns adopted can have a major effect on the resulting flood computed. Short and long duration rainfall data are both required for different sizes of catchments to determine and locate the flood producing critical storms in flood estimation. Design temporal patterns with different durations are therefore also required for distributing the storm rainfall in flood calculations. Patterns for a large number of durations with reasonably short time intervals are needed by designers to reduce the need for interpolation and to maintain the accuracy in obtaining the peak of the hydrograph. In this study, pluviograph data for the Upper Klang Catchment with records of over 30 years are used to derive temporal patterns for 20 standard durations as per ARR87. Rainfall temporal patterns for the upper Klang were derived for rainf...
The Journal of The Institution of Engineers, Malaysia, 2018
In this Study, the Muskingum and Lag river routing models were used to estimate the routing coeff... more In this Study, the Muskingum and Lag river routing models were used to estimate the routing coefficients of Klang river using flood records of gauging stations at Leboh Pasar and Sulaiman Bridge, for a river reach of 900m between the two gauging stations. Recorded inflow hydrographs at Leboh Pasar and outflow hydrographs at Suilaman Bridge were used to calibrate and validate the Muskingum and Lag routing models. Best fit routing parameters for the models were derived using the optimization module of HEC-HMS, and the average parameters obtained were used to validate the routing models using different sets of flood events. The outflow hydrographs at Sulaiman Bridge derived from routing models were used to compare with the observed hydrographs by plotting the hydrographs for visual inspections. The ability to produce the observed flow at the Sulaiman Bridge by the routing models were also assessed statistically by calculating the goodness of fit indices from the routed and observed hyd...
A set of quality control streamflow data is always required in the planning, design and managemen... more A set of quality control streamflow data is always required in the planning, design and management of water resources projects. Although every effort has been made by the authority in the collection of complete and continuous hydrological data such as rainfall and streamflow, gaps and incomplete data sets with inadequate length are always encountered, as is always the case. These can be due to faulty field instruments, the occurrence of natural disasters and other reasons. Over the years, various techniques have been developed to infill the missing data, especially the streamflow data. These techniques include regression analysis ,rainfall runoff modelling and the use of artificial neural networks(ANN) data driven models. In this study, the HEC-HMS model is used to simulate long term daily streamflow of Sg Melaka. The process involved using recorded flow and rainfall data of 1989-1992 to calibrate the model and the model validation using records of 1985-1986. Results show that the m...
2012 International Conference on Advanced Computer Science Applications and Technologies (ACSAT), 2012
ABSTRACT With the introduction of World Wide Web, users are able to connect and interact with eac... more ABSTRACT With the introduction of World Wide Web, users are able to connect and interact with each other anywhere in this world easily. However, elderly users may not be familiar with these technologies, some are even unable to cope with the rapid changes of World Wide Web. In fact, they are slow and unfamiliar with the latest trends and technology. This paper aims at addressing the problem of the gap between elderly users and the rapid changes of Internet Technologies. We use different techniques of user centred design in order to abstract design requirement for elderly users. These techniques help to gather the necessary user requirements from the elderly users. We apply these techniques to a simple case study - Web Site Design. We develop a combination of low-fidelity prototype and high-fidelity prototype to get the different perspectives of the elderly users for establishing usability requirement.
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