Urban Stormwater Management Manual for Malaysia Call 6012 710-2620

http://ift.tt/1jypUc5 Call (6012)710 2620 Manual Saliran Mesra Alam Malaysia (MSMA), or in English the Urban Stormwater Management Manual for Malaysia is the urban drainage design standard first printed by the Department of Irrigation and Drainage Malaysia (D.I.D) in 2000. It is required by law for all engineers in Malaysia to build drainage works to comply with the requirements of MSMA. Eleven years after its first publication, DID has completely amended the first edition of MSMA (MSMA1) with the release of the second edition (MSMA2). There are a lot of differences in the second edition including the following (based on case studies completed for Kuala Lumpur): 1. The design rainfall has gone up by up to 126% for ten out of the 14 storm stations in Kuala Lumpur. 2. The design flow using the Rational Method has gone up by up to 131% for commercial and city area. 3. The Site Storage Requirement for On-Site Detention for a factory lot in Kuala Lumpur has gone up by up to 235%, 4. The storage volume of a detention basin has gone up by up to 130%. The hike in the magnitudes of the main design parameters as described above can be due to the changes between the first and the second editions of MSMA as follows: 1. Longer storm data covering 100 more rainfall stations in Peninsular Malaysia. This gives rise to in higher storm intensities for certain durations and Average Recurrence Intervals. 2. West Malaysia is now grouped into 5 regions for the determination of the temporal pattern, compared to previously 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. 3. 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 changes in the estimated peak flow. 4. The Time-Area Method in MSMA2 is affected by the changes in the rainfall intensites, temporal patterns and the loss model used. For Kuala Lumpur it is noted that the rainfall intensities have increased and the temporal pattern is more peaky, thus giving rise to a more peaky flow hydrograph. 5. The Site Storage Requirement (SSR) based on the Approximate Swinburne Method in MSMA2 is higher than that using the Swinburne Method in the first edition. The second editon used the approximate method based on a set of approximation tables and this has resulted in an over estimation of the SSR's. 6. The storage volume of a detention basin has gone up using MSMA2 compared to the first edition because of the increase in the rainfall intensities, temporal patterns and the choice of loss rate. In view of the many changes 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 changes quickly. The tool is a urban drainage design software designed for MSMA. The software is developed by Ir. Dr. Quek Keng Hong- a practising engineer in Malaysia. MSMAware also covers the East Malaysian state of Sarawak where more than a dozen rainfall stations and their temporal patterns are included into the software. URBAN STORMWATER MANAGEMENT MANUAL FOR MALAYSIA : 00:00:05 Urban Stormwater Management Manual for Malaysia 00:00:06 Urban Stormwater Management Manual 00:00:07 Department of Irrigation and Drainage Malaysia 00:00:08 MSMA2 00:00:09 On-Site Detention Urban Stormwater Management Manual for Malaysia Call 6012 710-2620
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