Urban Stormwater Management Manual for Malaysia Tel (6012)-7102620
http://msmaware.com/blog/msma-software/
Call 6012 710-2620
The urban drainage design standard first published by the Department of Irrigation and Drainage Malaysia in 2000 is the Urban Stormwater Management Manual for Malaysia or the Manual Saliran Mesra Alam Malaysia (MSMA). Fullfilment of the requirements of MSMA when designing drainage system is required by law of all engineers in Malaysia. Eleven years after its first publication, DID has completely updated the first edition of MSMA (MSMA1) with the publishing of the second edition (MSMA2). There are numerous alterations in the second edition including the following (based on case studies done for Kuala Lumpur):
ten out of the fourteen storm stations in Kuala Lumpur have its design rainfall increased by up to 126%.
For commercial and city area, the design discharge using the Rational Method has increased by up to 131%.
The Site Storage Requirement for OSD for a factory site in Kuala Lumpur has increased by up to 235%,
The storage of a detention pond has increased by up to 130%.
The hike in the magnitudes of the main design parameters as outlined above can be attributed to the differences between the first and the second editions of MSMA as follows:
135 storm stations in Peninsular Malaysia with longer rainfall data. This results in higher storm intensities for certain durations and ARI's.
Peninsular Malaysia is now divided into five regions for the determination of the rainfall temporal pattern, compared to the first edition where it was divided into east and west coast of the Peninsula. The differences in temporal patterns give rise to dissimilar hydrograph peaks and shapes.
Not affected by rainfall durations and intensities, and whether a catchment is urban/rural in condition, the coefficient of runoff in the Rational Method is now determined according to the types of landuse. This resulted in differences in the estimated peak discharge.
The Time-Area Method in the second editon is affected by the differences in the rainfall intensites, temporal patterns and the loss model used. For Kuala Lumpur it is noticed that the rainfall intensities have increased and the rainfall temporal pattern is more peaky, thus resulting in a more peaky discharge hydrograph.
The Site Storage Requirement (SSR) based on the Approximate Swinburne Method in the second editon is higher than that using the Swinburne Method in MSMA1. The approximate method in the second editon has caused an over estimation of the SSR's.
The storage of a detention pond has increased using the second editon compared to MSMA1 because of the increase in the rainfall intensities, temporal patterns and the choice of loss rate.
In view of the many differences in computational procedures between the first and second editions of MSMA, a tool is developed to help engineers to carry out the computations using both editions accurately and to allow comparison be made of their differences quickly. The tool is a stormwater design software designed for MSMA. The software is created by Ir. Dr. Quek Keng Hong- a practising professional engineer in Malaysia. MSMAware also contains more than a dozen rainfall stations and their temporal patterns in the East Malaysian state of Sarawak.
Urban Stormwater Management Manual for Malaysia Tel (6012)-7102620
https://www.youtube.com/watch?v=lMzPpnakrEs