MSMA workshop Phone 6012-7102620

MSMA workshop Phone 6012-7102620

http://msmaware.com/blog/urban-stormwater-management-manual-for-malaysia-or-the-manual-saliran-mesra-alam-malaysia-msma/
Ph (6012)-7102620

The Urban Stormwater Management Manual or the Manual Saliran Mesra Alam Malaysia (MSMA) is the urban drainage design guideline first published by the Department of Irrigation and Drainage Malaysia in early 2000. Compliance with the requirements of MSMA when designing drainage system is required legally of all engineers in Malaysia. The Department of Irrigation and Drainage has completely amended the first edition of MSMA (known as MSMA1) with the publication of the second edition (known as MSMA2) about 11 years after its first edition. There are numerous changes in the second edition including (based on case studies done for Kuala Lumpur):

10 out of the fourteen rainfall stations in Kuala Lumpur have its design rainfall increased by up to 124%.
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 234%,
The storage volume of a detention basin has increased by up to 128%.

The hike in the values of the main design parameters as described above can be attributed to the differences between the first and the second editions of MSMA as follows:

Longer precipitation data covering 100 more storm stations in Peninsular Malaysia. The rainfall intensities for most ARI's are higher.

Peninsular Malaysia is now divided into 5 regions for the computation of the rainfall temporal pattern, compared to the first edition where it was divided into east and west coast of the Peninsula. The dissimilar hydrograph peaks and shapes caused by the differences in temporal patterns.

The coefficient of runoff in the Rational Method is now established according to the types of landuse, and not influenced by rainfall durations and intensities, and whether a catchment is urban/rural in condition. 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 Approximate Swinburne Method in the second editon gives higher Site Storage Requirement (SSR) than the Swinburne Method in MSMA1. The approximate method in the second editon has given rise to an over estimation of the SSR's.

Compared to MSMA1, the increase in the rainfall intensities, temporal patterns and the selection of loss rate have given rise to a rise in the storage volume of a detention basin using the second edition.

In view of the many differences in computational methods 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 speedily. A drainage design software has been created for MSMA. Ir. Dr. Quek Keng Hong- a practising engineer in Malaysia is the developer of the software. MSMAware also covers the East Malaysian state of Sarawak where more than a dozen rainfall stations and their temporal patterns are programmed into the software.





MSMA workshop Phone 6012-7102620








https://www.youtube.com/watch?v=ROakUoy_y38