---
title: New MSMA 2 data for Sabah and Sarawak based on Estimation of Design Rainstorm in Sabah and Sarawak (SUStoM) – Revised and Updated 2018
description: "[**Reference Project**](https://largefilehosting.s3.ap-northeast-1.amazonaws.com/ProjectSharing/Update%20Blogpost%20Link/10862%202.4.12.0-backup-2.4.16.0-230420164533.zip) Rainfall data of Sabah and Sarawak are implemented according to [**“Estimation of Design Rainstorm in Sabah and Sarawak (Revised and Updated 2018)”**](https://drive.google.com/file/d/1h6yv9J4Nrlnl7-OSXW0Ke6MpX5B1LE_8/view)**.** Over 100 of rain gauge locations are added for the East Malaysia region and are in…"
url: "https://mes100.com/docs/new-msma-2-data-for-sabah-and-sarawak-based-on-estimation-of-design-rainstorm-in-sabah-and-sarawak-revised-and-updated-2018/"
updated: "2026-10-12"
category: Exposition / MSMA
---

# New MSMA 2 data for Sabah and Sarawak based on Estimation of Design Rainstorm in Sabah and Sarawak (SUStoM) – Revised and Updated 2018

[**Reference Project**](https://largefilehosting.s3.ap-northeast-1.amazonaws.com/ProjectSharing/Update%20Blogpost%20Link/10862%202.4.12.0-backup-2.4.16.0-230420164533.zip)

Rainfall data of Sabah and Sarawak are implemented according to [**“Estimation of Design Rainstorm in Sabah and Sarawak (Revised and Updated 2018)”**](https://drive.google.com/file/d/1h6yv9J4Nrlnl7-OSXW0Ke6MpX5B1LE_8/view)**.** Over 100 of rain gauge locations are added for the East Malaysia region and are in conjunction with MSMA 2nd Edition. It is crucial especially in Sabah area, whereby it was limited only to MSMA 1st edition in stormwater management design previously. Other new items such as temporal pattern based on cluster categories and areal reduction factor (ARF) are also in the new version. 

# **Raingauge Location** 

New Rain gauge locations are added in Sabah and Sarawak along with the map attached. The list of parameters for both Sabah and Sarawak can be referred to in Table 4.1 and Table 4.2, respectively. 

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image1-5.png?w=1080&ssl=1)

*Image 1 : Rain gauge locations in MiTS 3.2.18.0 for MSMA 2nd Edition*

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image10-1.png?w=1080&ssl=1)

*Image 2 : Parts of IDF Parameter list for Sabah Region *(Table 4.1**)

## **Gridded HP26 in MiTS 3**

Besides the rain gauges, HP26 also publishes λ, κ, θ, η for every cell of a 10 km and a 20 km grid over Sabah and Sarawak: 2,346 and 646 cells. In MiTS 3, set the **IDF source** to **Gridded HP1 / HP26** and enter the site coordinate. MiTS selects the nearest published grid cell and uses its coefficients, along with the CCF that HP26 publishes for that cell and ARI. It is intended for an ungauged site, which would otherwise have to borrow the values of a gauge some distance away. Where long, reliable local gauge records exist, the gauge remains a valid choice. See [Choosing the IDF Source](https://mes100.com/docs/choosing-the-idf-source-in-mits/).

# **Areal Reduction Factor**

Areal Reduction Factor (ARF) is a value applied to rainfall of a certain area and duration to give the areal rainfall of the same duration and return period. ARF is implemented based on Table 6.12 and 6.13 for Sabah and Sarawak region, respectively. 

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image6.png?w=1080&ssl=1)

*Image 3 : ARF for Sabah and Sarawak Region*

Take Kuching, Sarawak for example. Given the coefficient as stated below, the area of catchment is 10000 ha (100 km2) and 360 minutes (6-hr) duration for 10 years ARI.

ƛ = 84.6865, K = 0.1820, θ = 0.4599, ɳ = 0.7092

$$ \mathrm{Rainfall}\;\mathrm{Intensity}\;(\mathrm{mm}/\mathrm{hr})\;=\;\frac{(84.6865){(10)}^{0.1820}}{{(6+0.4599)}^{0.7092}} $$

= 34.30 mm/hr

Based on Table 6.13, the ARF of 100 km2 area for 6 hours is 0.772.

Areal Rainfall Intensity (mm/hr) = 0.772 x 34.30

= 26.48 mm/hr

MiTS auto calculates the rainfall intensity based on raingauge location, area and duration.

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image4-4.png?w=1080&ssl=1)

*Image 4 : Areal Rainfall Intensity for Kuching, Sarawak with 100km2 area*

# **Temporal Patterns**

There are nine cluster regions in East Malaysia with 4 and 5 regions located in Sabah and Sarawak respectively with different Temporal Patterns. The nine clusters created are shown in Figure 6.1. Each of the clusters results in different temporal patterns, which are tabulated in Table 6.2 to Table 6.10. 

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image4-3.png?w=1080&ssl=1)

*Image 5 : Nine regions in Sabah and Sarawak*

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image7-1.png?w=1080&ssl=1)

*Image 6 : Example of temporal pattern* 

Calculation and Temporal Patterns created in MiTS are reflected upon the region assigned in the input. 

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image3-5.png?w=1080&ssl=1)

*Image 7 : Nine clusters are included with different temporal pattern each*

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image2-5.png?w=1080&ssl=1)

*Image 8 : One of the temporal patterns created in MiTS output*

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image3-4.png?w=1080&ssl=1)

*Image 9 : Textual report on the temporal pattern calculation* 

# Climate Change Factor

The Climate Change Factor (CCF) values for Sabah and Sarawak are also added in the new guideline. The 1-day CCF for these stations were calculated for ARI of 2, 5, 10, 20, 25, 50 and 100 years. CCF value can be referred based on Table 7.1 and 7.2 for Sabah and Sarawak region, respectively. 

![](https://i0.wp.com/mes100.com/wp-content/uploads/2020/04/image5-1.png?w=1080&ssl=1)

*Image 10 : Parts of CCF value list for Sabah Region *(Table 7.1**)

### *Related*

 [![](https://i0.wp.com/mes100.com/wp-content/uploads/2024/10/me-small.jpg?resize=100%2C100&ssl=1)](https://mes100.com/author/admin/)[Ngu Soon Hui](https://mes100.com/author/admin/)

I’m the [Benevolent Dictator for Life](https://en.wikipedia.org/wiki/Benevolent_dictator_for_life) for MiTS Software cum Editor of this website. Read more [here](/about-ngu-soon-hui/).

You can also contact me at soonhui@mes100.com