Rozi Abdullah - Academia.edu (original) (raw)

Papers by Rozi Abdullah

Water Resources Management

International Journal of Design & Nature and Ecodynamics, 2022

Evaporation is influenced by several meteorological parameters, evaporation data are usually diff... more Evaporation is influenced by several meteorological parameters, evaporation data are usually difficult to obtain compared to rainfall data, especially in arid regions. Developing a monthly evaporation prediction model in arid regions in terms of available meteorological data is a significant step. The data used in this study for modeling are monthly measurements to cover substantial continuity over a period of 18 years between January 2000 and December 2017. Stepwise and backward multiple linear regression techniques were used with a new procedure of variable selection to select the best model. Temperature, wind speed, relative humidity and sunshine hours were used as a independent variables in the multiple linear regression (MLR) technique to establish the best prediction of the evaporation model. To examine the MLR evaporation developed model in the current study, MLR results were compared with the most common evaporation models commonly used in arid regions such as Kharufa and Kh...

Proceedings of AICCE'19, 2019

This article aims to determine the criteria needed and to create a map of location suitability fo... more This article aims to determine the criteria needed and to create a map of location suitability for the retention pond site selection with the case study in the city of Medan, the province of North Sumatra, Indonesia. The multi criteria decision analysis (MCDA) based on geographic information system (GIS) was applied to reach this goal. Pairwise comparison (PC) method of analytic hierarchy process (AHP) is used to calculate the weight of each criterion and the weighted linear combination (WLC) method applied to combine the criterion or factor maps. All of the data processing and analysis were completed using IDRISI-Selva software version 17, where the final result was a suitability map. Seven factor maps (i.e. rainfall, runoff, slope, aquifer, distance to channels, distance to river, and land use/ land cost) and seven constraint maps (i.e. well, road, strategic area 1, strategic area 2, utilities, railway, land use) are established and involved in this site selection model. The obtained suitability map has four levels of suitability, namely low, moderate, high and very high suitable with an area of 0 ha, 379 ha, 12,778 ha and 1291 ha, respectively. The results of this study can be used as input to decision makers in urban areas, especially in terms of selecting the location of retention ponds to improve their rainwater management performance.

Water Environment Research, 2012

sbe.hw.ac.uk

... Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the ... more ... Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, 21 – 24 Nov 2000, pp.166 -172. Ahmad N. (2008). ... Diebolt J., El-Aroui MA, Garrido M. and Girard S. (2003). ...

International Journal of Engineering & Technology, 2014

The behavior of reservoir systems can be investigated using Critical Period (CP) which determines... more The behavior of reservoir systems can be investigated using Critical Period (CP) which determines the aggregation level of the data (monthly or annual) that are required to be utilized in the reservoir analysis. Currently there are a number of methods that could approximate the behavior of reservoir systems, however the efficiency of these approaches have not been studied and verified for the Malaysia Rivers. In this study two different hypothetical reservoirs on Malaysia Rivers are selected. The stream flow data are subjected to preliminary analysis and evaluation of the fittest probability distribution function. Afterwards, the CP is estimated by applying a Monte Carlo simulation technique and considering performance indices. The CP from this study is used to determine the within-year or over-year behavior and these results are compared with those of the previous well-known equations in this area. It is observed that existing equations are incomplete and other parameters such as r...

Most of the abstracts were submitted on floppy disk and were edited to achieve a uniform format a... more Most of the abstracts were submitted on floppy disk and were edited to achieve a uniform format and type face. Each contributor is responsible f o r the accuracy and content of his or her own paper. Statements of the contributors from outside the U. S. Department of Agriculture may not necessarily reflect the policy of the Department. Some participants did not submit abstracts, so they have not been included. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U. S. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable. Remarks about pesticides appear in some technical papers contained in these proceedings. Publication of these statements does not constitute endorsement or recommendation of them by the conference sponsors, nor does it imply that uses discussed have been registered. Use of most pesticides is regulated by State and Federal Law. Applicable regulations must be obtained from the appropriate regulatory agencies. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish and other wildlife-if they are not handled and applied properly. Use all pesticides selectively and carefully. Follow recommended practices given on the label for use and disposal of pesticides and pesticide containers.

MATEC Web of Conferences, 2016

Gravity separator tanks are used to separate oil from water in treatment units. Achieving the bes... more Gravity separator tanks are used to separate oil from water in treatment units. Achieving the best flow uniformity in a separator tank will improve the maximum removal efficiency of oil globules from water. In this study, the effect on hydraulic performance of different baffle structure positions inside a tank was investigated. Experimental data and 2D computation fluid dynamics were used for analysis. In the numerical model, two-phase flow (drift flux model) was used to validate one-phase flow. For laboratory measurements, the velocity fields were measured using an acoustic Doppler velocimeter. The measurements were compared with the result of the computational model. The results of the experimental and computational simulations indicate that the best location of a baffle structure is achieved when the standard deviation of the velocity profile and the volume of the circulation zone inside the tank are minimized.

The Journal of The Institution of Engineers, Malaysia

Floods are known as one of the world’s most frequent and devastating events. Techniques to predic... more Floods are known as one of the world’s most frequent and devastating events. Techniques to predict and estimate the size of floods is depend on the availability of hydrological data. Using the conceptual of lump model, rainfall-runoff method is widely used in design flood estimation, which represents the input of rainfall and catchment characteristics such as rainfall depth, rainfall intensity, baseflow and losses. 7o calculate the catchments runoff, amount of losses shall be determine accurately by considering various source of the rainfall losses such as evaporation, inßltration, interception, depression storage and loss in groundwater recharge. In Malaysia, the common technique to estimate the hydrological losses is using initial and constant loss method. Furthermore, the value has been used in Urban Stormwater Manual for Malaysia (USMA) are adopted from the other literatures which is not represented the value from local catchment.7he objective of this study is to derive the init...

World applied sciences journal, 2013

Rectangular separator tanks used gravity settling to separate oil from water in treatment units. ... more Rectangular separator tanks used gravity settling to separate oil from water in treatment units. In this study, in order to increase the performance of separator tanks, the effect of different positions of baffle structure on improving the uniformity of flow was investigated. Two dimensional computation fluid dynamics (CFD) and one phase flow model was built to simulate the flow properties in the gravity separator tanks including the velocity profile distribution and volume of circulation region. A CFD programme, Flow 3D ver.10 was used in which finite volume method is used for solution of water flow equations and RNG turbulent model with the Navier-Stokes equations. The volume of fluid (VOF) method was used for tracking of free surface in simulation program. The result of numerical simulation indicate that the best location of baffle is obtained when the standard deviation of the velocity distribution and volume of circulation zone along the separator tanks is minimized. In other w...

Developing a prediction relationship for total (i.e. within-year plus over-year) storage capacity... more Developing a prediction relationship for total (i.e. within-year plus over-year) storage capacity of reservoir systems is beneficial because it can be used as an alternative to the analysis of reservoirs during designing stage and gives an opportunity to planner to examine and compare different cases in a fraction of time required for complete analysis where detailed analysis is not necessary. Existing relationships for storage capacity are mostly capable of estimating over-year storage capacity and total storage capacity can be obtained through relationships for adjusting over-year capacity and there is no independent relationship to estimate total storage capacity. Moreover these relationships do not involve vulnerability performance criterion and are not verified for Malaysia Rivers. In this study two different reservoirs in Southern part of Peninsular Malaysia, Melaka and Muar, are analyzed through a Monte Carlo simulation approach involving performance metrics. Subsequently the...

Environmental Engineering and Management Journal

Desalination and Water Treatment, 2016

AbstractOil and water separation due to gravitation is extensively applied in water and wastewate... more AbstractOil and water separation due to gravitation is extensively applied in water and wastewater treatment to get rid of the oil droplets. Optimum inlet baffle configuration may facilitate the formation of favorable flow fields and heighten the separator tank’s removal efficiency. Experimental tests were carried out to ascertain appropriate position for an inlet baffle in a rectangular separator tank. There are four parts in the experimental measurements. First of all, measured velocity fields make use of an acoustic Doppler velocimeter. Second of all, the uniformity of flow is measured by drawing a comparison of the standard deviation of the velocity profile. The oil concentration at both inlet and outlet points was later on assessed. Finally, the separation tank’s removal efficiency was evaluated. The results provide an indication that a uniform flow pattern improved when the inlet baffle position gave a minimum standard deviation value. In this case, the minimum concentration of oil at the outlet and...

Applied Mechanics and Materials, 2015

Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a res... more Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a reservoir system prior to analysis is advantageous because then the input data interval can be selected to match the requirement. In this sense, over-year systems (CP > 1 year) can be adequately analyzed using annual time-series data, whereas for within-year systems (CP < 1 year), only the critical 12 months in the data record are needed to be considered. The current standard demand parameter method for prediction of the behavior of reservoirs is based only on demand and coefficient of variation of annual flows. However, performance measures such as reliability and vulnerability are also important in the critical period of reservoir systems. Hence, the objective of this study, is to develop a predictive relationship for critical period involving standard demand parameter and both reliability and vulnerability performance indices as for use during the reservoir planning stage. The Joho...

Applied Mechanics and Materials, 2015

Storage–yield–reliability (S–Y–R) relationship is useful in many areas of hydrology and water res... more Storage–yield–reliability (S–Y–R) relationship is useful in many areas of hydrology and water resources. With the availability of such a relationship, reservoir planning analysis can be implemented much more rapidly and at a much shorter time needed for sequential analysis applying time series data. Existing relationships have been developed mostly for over-year capacity without considering both reliability and vulnerability performance indices. Hence, in this study, streamflow data from Johor river was used to develop a predictive relationship for total (i.e. within-year plus over-year) storage capacity involving both reliability and vulnerability performance indices as for use during reservoir planning. The reservoir was analyzed using 1000 sequences of synthetic data having the same length as historical data involving both time-based reliability and vulnerability performance indices by modified SPA. The model was then calibrated based on the mean of 1000 simulation results. Subse...

Applied Mechanics and Materials, 2015

Gravity Separator Tanks are Used to Separate Oil from Water in Treatment Units. Achieving the Bes... more Gravity Separator Tanks are Used to Separate Oil from Water in Treatment Units. Achieving the Best Flow Uniformity in a Separator Tank will Improve the Maximum Removal Efficiency of Oil Globules from Water. in this Study, the Effect on Hydraulic Performance of Different Inlet Baffle Height inside a Tank was Investigated. some Experimental Tests were Done for Verification the Velocity Profile with Numerical Results Using ADV (Acoustic Doppler Velocimeter). A CFD Programme, Flow 3D Ver.10 was Used in which Finite Volume Method is Used for Solution of Water Flow Equations and RNG Turbulent Model with the Navier-Stokes Equations. the Volume of Fluid (VOF) Method was Used for Tracking of Free Surface in Simulation Program. the Results of the Numerical Simulation Show that the Separation Tank Performance can Be Improved by Altering the Geometry of the Tank and the Effects of Inlet Baffle Height on the Efficiency of the Separation Tank are Investigated via Assessment of the Circulation Zon...

Advances in Environmental Biology

Capabilities of radar to measure rainfall offer an enormous potential to improve the quality of r... more Capabilities of radar to measure rainfall offer an enormous potential to improve the quality of rainfall measurement. In order to estimates rainfall from radar data, the reflectivity data have to convert using an empirical equation called reflectivity-rainfall (Z-R) relationship. The Z-R relationship that is used in Malaysia was based on Marshall and Palmer (1948) and this equation is seen no longer suit with Malaysia condition. Therefore, a new equation should be developed. The reflectivity data between year of 2005 and 2008 at Alor Star Radar and the rainfall gauged data form 14 rain gauge in the Northern of Peninsular Malaysia were synchronized. Calibration and validation process were performed between rainfall radar and gauge data. Four statistical measures such as Mean Error, Absolute Mean Error, Root Mean Square Error and Bias were used as indicators. By minimising the errors, the Z-R relationship for the Alor Star Radar was determined to be Z = 40R 1.6. To determine the best ...

The Malaysian economy has gone through rapid structural changes since independence in 1957. Progr... more The Malaysian economy has gone through rapid structural changes since independence in 1957. Progressive development from agriculture to an industrialized economy has shifted the population into urban centers. Urban development is necessarily to meet the need of urban population. Urbanization will increase the construction of paved area that has significant changed on the hydrologic and hydraulic characteristics of the catchments.

Water Resources Management

International Journal of Design & Nature and Ecodynamics, 2022

Evaporation is influenced by several meteorological parameters, evaporation data are usually diff... more Evaporation is influenced by several meteorological parameters, evaporation data are usually difficult to obtain compared to rainfall data, especially in arid regions. Developing a monthly evaporation prediction model in arid regions in terms of available meteorological data is a significant step. The data used in this study for modeling are monthly measurements to cover substantial continuity over a period of 18 years between January 2000 and December 2017. Stepwise and backward multiple linear regression techniques were used with a new procedure of variable selection to select the best model. Temperature, wind speed, relative humidity and sunshine hours were used as a independent variables in the multiple linear regression (MLR) technique to establish the best prediction of the evaporation model. To examine the MLR evaporation developed model in the current study, MLR results were compared with the most common evaporation models commonly used in arid regions such as Kharufa and Kh...

Proceedings of AICCE'19, 2019

This article aims to determine the criteria needed and to create a map of location suitability fo... more This article aims to determine the criteria needed and to create a map of location suitability for the retention pond site selection with the case study in the city of Medan, the province of North Sumatra, Indonesia. The multi criteria decision analysis (MCDA) based on geographic information system (GIS) was applied to reach this goal. Pairwise comparison (PC) method of analytic hierarchy process (AHP) is used to calculate the weight of each criterion and the weighted linear combination (WLC) method applied to combine the criterion or factor maps. All of the data processing and analysis were completed using IDRISI-Selva software version 17, where the final result was a suitability map. Seven factor maps (i.e. rainfall, runoff, slope, aquifer, distance to channels, distance to river, and land use/ land cost) and seven constraint maps (i.e. well, road, strategic area 1, strategic area 2, utilities, railway, land use) are established and involved in this site selection model. The obtained suitability map has four levels of suitability, namely low, moderate, high and very high suitable with an area of 0 ha, 379 ha, 12,778 ha and 1291 ha, respectively. The results of this study can be used as input to decision makers in urban areas, especially in terms of selecting the location of retention ponds to improve their rainwater management performance.

Water Environment Research, 2012

sbe.hw.ac.uk

... Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the ... more ... Proceedings of Fresh Perspectives on Hydrology and Water Resources in Southeast Asia and the Pacific, Christchurch, New Zealand, 21 – 24 Nov 2000, pp.166 -172. Ahmad N. (2008). ... Diebolt J., El-Aroui MA, Garrido M. and Girard S. (2003). ...

International Journal of Engineering & Technology, 2014

The behavior of reservoir systems can be investigated using Critical Period (CP) which determines... more The behavior of reservoir systems can be investigated using Critical Period (CP) which determines the aggregation level of the data (monthly or annual) that are required to be utilized in the reservoir analysis. Currently there are a number of methods that could approximate the behavior of reservoir systems, however the efficiency of these approaches have not been studied and verified for the Malaysia Rivers. In this study two different hypothetical reservoirs on Malaysia Rivers are selected. The stream flow data are subjected to preliminary analysis and evaluation of the fittest probability distribution function. Afterwards, the CP is estimated by applying a Monte Carlo simulation technique and considering performance indices. The CP from this study is used to determine the within-year or over-year behavior and these results are compared with those of the previous well-known equations in this area. It is observed that existing equations are incomplete and other parameters such as r...

Most of the abstracts were submitted on floppy disk and were edited to achieve a uniform format a... more Most of the abstracts were submitted on floppy disk and were edited to achieve a uniform format and type face. Each contributor is responsible f o r the accuracy and content of his or her own paper. Statements of the contributors from outside the U. S. Department of Agriculture may not necessarily reflect the policy of the Department. Some participants did not submit abstracts, so they have not been included. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U. S. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable. Remarks about pesticides appear in some technical papers contained in these proceedings. Publication of these statements does not constitute endorsement or recommendation of them by the conference sponsors, nor does it imply that uses discussed have been registered. Use of most pesticides is regulated by State and Federal Law. Applicable regulations must be obtained from the appropriate regulatory agencies. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish and other wildlife-if they are not handled and applied properly. Use all pesticides selectively and carefully. Follow recommended practices given on the label for use and disposal of pesticides and pesticide containers.

MATEC Web of Conferences, 2016

Gravity separator tanks are used to separate oil from water in treatment units. Achieving the bes... more Gravity separator tanks are used to separate oil from water in treatment units. Achieving the best flow uniformity in a separator tank will improve the maximum removal efficiency of oil globules from water. In this study, the effect on hydraulic performance of different baffle structure positions inside a tank was investigated. Experimental data and 2D computation fluid dynamics were used for analysis. In the numerical model, two-phase flow (drift flux model) was used to validate one-phase flow. For laboratory measurements, the velocity fields were measured using an acoustic Doppler velocimeter. The measurements were compared with the result of the computational model. The results of the experimental and computational simulations indicate that the best location of a baffle structure is achieved when the standard deviation of the velocity profile and the volume of the circulation zone inside the tank are minimized.

The Journal of The Institution of Engineers, Malaysia

Floods are known as one of the world’s most frequent and devastating events. Techniques to predic... more Floods are known as one of the world’s most frequent and devastating events. Techniques to predict and estimate the size of floods is depend on the availability of hydrological data. Using the conceptual of lump model, rainfall-runoff method is widely used in design flood estimation, which represents the input of rainfall and catchment characteristics such as rainfall depth, rainfall intensity, baseflow and losses. 7o calculate the catchments runoff, amount of losses shall be determine accurately by considering various source of the rainfall losses such as evaporation, inßltration, interception, depression storage and loss in groundwater recharge. In Malaysia, the common technique to estimate the hydrological losses is using initial and constant loss method. Furthermore, the value has been used in Urban Stormwater Manual for Malaysia (USMA) are adopted from the other literatures which is not represented the value from local catchment.7he objective of this study is to derive the init...

World applied sciences journal, 2013

Rectangular separator tanks used gravity settling to separate oil from water in treatment units. ... more Rectangular separator tanks used gravity settling to separate oil from water in treatment units. In this study, in order to increase the performance of separator tanks, the effect of different positions of baffle structure on improving the uniformity of flow was investigated. Two dimensional computation fluid dynamics (CFD) and one phase flow model was built to simulate the flow properties in the gravity separator tanks including the velocity profile distribution and volume of circulation region. A CFD programme, Flow 3D ver.10 was used in which finite volume method is used for solution of water flow equations and RNG turbulent model with the Navier-Stokes equations. The volume of fluid (VOF) method was used for tracking of free surface in simulation program. The result of numerical simulation indicate that the best location of baffle is obtained when the standard deviation of the velocity distribution and volume of circulation zone along the separator tanks is minimized. In other w...

Developing a prediction relationship for total (i.e. within-year plus over-year) storage capacity... more Developing a prediction relationship for total (i.e. within-year plus over-year) storage capacity of reservoir systems is beneficial because it can be used as an alternative to the analysis of reservoirs during designing stage and gives an opportunity to planner to examine and compare different cases in a fraction of time required for complete analysis where detailed analysis is not necessary. Existing relationships for storage capacity are mostly capable of estimating over-year storage capacity and total storage capacity can be obtained through relationships for adjusting over-year capacity and there is no independent relationship to estimate total storage capacity. Moreover these relationships do not involve vulnerability performance criterion and are not verified for Malaysia Rivers. In this study two different reservoirs in Southern part of Peninsular Malaysia, Melaka and Muar, are analyzed through a Monte Carlo simulation approach involving performance metrics. Subsequently the...

Environmental Engineering and Management Journal

Desalination and Water Treatment, 2016

AbstractOil and water separation due to gravitation is extensively applied in water and wastewate... more AbstractOil and water separation due to gravitation is extensively applied in water and wastewater treatment to get rid of the oil droplets. Optimum inlet baffle configuration may facilitate the formation of favorable flow fields and heighten the separator tank’s removal efficiency. Experimental tests were carried out to ascertain appropriate position for an inlet baffle in a rectangular separator tank. There are four parts in the experimental measurements. First of all, measured velocity fields make use of an acoustic Doppler velocimeter. Second of all, the uniformity of flow is measured by drawing a comparison of the standard deviation of the velocity profile. The oil concentration at both inlet and outlet points was later on assessed. Finally, the separation tank’s removal efficiency was evaluated. The results provide an indication that a uniform flow pattern improved when the inlet baffle position gave a minimum standard deviation value. In this case, the minimum concentration of oil at the outlet and...

Applied Mechanics and Materials, 2015

Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a res... more Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a reservoir system prior to analysis is advantageous because then the input data interval can be selected to match the requirement. In this sense, over-year systems (CP > 1 year) can be adequately analyzed using annual time-series data, whereas for within-year systems (CP < 1 year), only the critical 12 months in the data record are needed to be considered. The current standard demand parameter method for prediction of the behavior of reservoirs is based only on demand and coefficient of variation of annual flows. However, performance measures such as reliability and vulnerability are also important in the critical period of reservoir systems. Hence, the objective of this study, is to develop a predictive relationship for critical period involving standard demand parameter and both reliability and vulnerability performance indices as for use during the reservoir planning stage. The Joho...

Applied Mechanics and Materials, 2015

Storage–yield–reliability (S–Y–R) relationship is useful in many areas of hydrology and water res... more Storage–yield–reliability (S–Y–R) relationship is useful in many areas of hydrology and water resources. With the availability of such a relationship, reservoir planning analysis can be implemented much more rapidly and at a much shorter time needed for sequential analysis applying time series data. Existing relationships have been developed mostly for over-year capacity without considering both reliability and vulnerability performance indices. Hence, in this study, streamflow data from Johor river was used to develop a predictive relationship for total (i.e. within-year plus over-year) storage capacity involving both reliability and vulnerability performance indices as for use during reservoir planning. The reservoir was analyzed using 1000 sequences of synthetic data having the same length as historical data involving both time-based reliability and vulnerability performance indices by modified SPA. The model was then calibrated based on the mean of 1000 simulation results. Subse...

Applied Mechanics and Materials, 2015

Gravity Separator Tanks are Used to Separate Oil from Water in Treatment Units. Achieving the Bes... more Gravity Separator Tanks are Used to Separate Oil from Water in Treatment Units. Achieving the Best Flow Uniformity in a Separator Tank will Improve the Maximum Removal Efficiency of Oil Globules from Water. in this Study, the Effect on Hydraulic Performance of Different Inlet Baffle Height inside a Tank was Investigated. some Experimental Tests were Done for Verification the Velocity Profile with Numerical Results Using ADV (Acoustic Doppler Velocimeter). A CFD Programme, Flow 3D Ver.10 was Used in which Finite Volume Method is Used for Solution of Water Flow Equations and RNG Turbulent Model with the Navier-Stokes Equations. the Volume of Fluid (VOF) Method was Used for Tracking of Free Surface in Simulation Program. the Results of the Numerical Simulation Show that the Separation Tank Performance can Be Improved by Altering the Geometry of the Tank and the Effects of Inlet Baffle Height on the Efficiency of the Separation Tank are Investigated via Assessment of the Circulation Zon...

Advances in Environmental Biology

Capabilities of radar to measure rainfall offer an enormous potential to improve the quality of r... more Capabilities of radar to measure rainfall offer an enormous potential to improve the quality of rainfall measurement. In order to estimates rainfall from radar data, the reflectivity data have to convert using an empirical equation called reflectivity-rainfall (Z-R) relationship. The Z-R relationship that is used in Malaysia was based on Marshall and Palmer (1948) and this equation is seen no longer suit with Malaysia condition. Therefore, a new equation should be developed. The reflectivity data between year of 2005 and 2008 at Alor Star Radar and the rainfall gauged data form 14 rain gauge in the Northern of Peninsular Malaysia were synchronized. Calibration and validation process were performed between rainfall radar and gauge data. Four statistical measures such as Mean Error, Absolute Mean Error, Root Mean Square Error and Bias were used as indicators. By minimising the errors, the Z-R relationship for the Alor Star Radar was determined to be Z = 40R 1.6. To determine the best ...

The Malaysian economy has gone through rapid structural changes since independence in 1957. Progr... more The Malaysian economy has gone through rapid structural changes since independence in 1957. Progressive development from agriculture to an industrialized economy has shifted the population into urban centers. Urban development is necessarily to meet the need of urban population. Urbanization will increase the construction of paved area that has significant changed on the hydrologic and hydraulic characteristics of the catchments.