Employing nature to combat floods: some experiences from Malaysia

Natural undisturbed systems possess inherent mechanisms and their own ways and means of maintaining system stability. Forests and floodplains, also commonly known as wetlands, are nature's way of controlling floods. Forests and wetland forests control floods by controlling rainfall at source,...

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Main Authors: Chan, Ngai Weng, Ibrahim, Ab. Latif, Kung, Hsiang-te, Liu, Pin-Shuo
Other Authors: Ali, Juhary
Format: Book Section
Language:English
Published: Penerbit Ustara 2002
Subjects:
Online Access:http://eprints.utm.my/2532/
http://eprints.utm.my/2532/1/Employing-2002-Chan.pdf
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author Chan, Ngai Weng
Ibrahim, Ab. Latif
Kung, Hsiang-te
Liu, Pin-Shuo
author2 Ali, Juhary
author_facet Ali, Juhary
Chan, Ngai Weng
Ibrahim, Ab. Latif
Kung, Hsiang-te
Liu, Pin-Shuo
author_sort Chan, Ngai Weng
building UTeM Institutional Repository
collection Online Access
description Natural undisturbed systems possess inherent mechanisms and their own ways and means of maintaining system stability. Forests and floodplains, also commonly known as wetlands, are nature's way of controlling floods. Forests and wetland forests control floods by controlling rainfall at source, a concept only recently adopted by flood control agencies. Layered and densely forested areas intercept a significant amount of rainfall and regulate the flow of rain down branches, trunks and roots before reaching the river. Interception, the amount of rainfall caught in the forest crown, is about 10 - 15% of total rainfall. Least interception occurs when forests are thinned and exposed due to clearing, while maximum interception (often reaching 100 %) occurs with dense virgin forests made up of evergreen trees. During heavy rainstorms, rainwater commences to drift as mists or droplets to earth as "throughfall" which averages about 75 - 85% of rain in humid climates like Malaysia. Runoff from upstream also has to penetrate the forest before reaching the river, hence increasing lead time. Wetland forests along rivers, estuaries and coastal areas also give runoff from precipitation (which eventually gets into rivers) a place to spread out, serving as natural retention basins. Wetland forests act like sponges soaking and absorbing a lot of water down into the ground and then releasing it slowly over time. As much as 2.3 million litres of water is absorbed per hectare, depending on the nature of the soil. Forests hold the water and release it slowly. When forests are cleared or destroyed, all the rainwater gets into rivers at a relatively rapid time, resulting in flash floods. The concentration of water into the main river channel over a much shorter period of time dramatically increases flooding. It is vital for engineers and all scientists to work with natural systems rather than against them. In this respect, the JPS Malaysia has initiated the mandatory Manual for Environmentally Friendly Drainage for all development projects, indicating an all-important change of mindset from conventional engineering approach to a more comprehensive multi¬disciplinary approach that taps on the expertise of all disciplines.
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format Book Section
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institution Universiti Teknologi Malaysia
institution_category Local University
language English
last_indexed 2025-11-15T20:41:11Z
publishDate 2002
publisher Penerbit Ustara
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spelling utm-25322017-10-25T08:45:45Z http://eprints.utm.my/2532/ Employing nature to combat floods: some experiences from Malaysia Chan, Ngai Weng Ibrahim, Ab. Latif Kung, Hsiang-te Liu, Pin-Shuo Q Science (General) GE Environmental Sciences Natural undisturbed systems possess inherent mechanisms and their own ways and means of maintaining system stability. Forests and floodplains, also commonly known as wetlands, are nature's way of controlling floods. Forests and wetland forests control floods by controlling rainfall at source, a concept only recently adopted by flood control agencies. Layered and densely forested areas intercept a significant amount of rainfall and regulate the flow of rain down branches, trunks and roots before reaching the river. Interception, the amount of rainfall caught in the forest crown, is about 10 - 15% of total rainfall. Least interception occurs when forests are thinned and exposed due to clearing, while maximum interception (often reaching 100 %) occurs with dense virgin forests made up of evergreen trees. During heavy rainstorms, rainwater commences to drift as mists or droplets to earth as "throughfall" which averages about 75 - 85% of rain in humid climates like Malaysia. Runoff from upstream also has to penetrate the forest before reaching the river, hence increasing lead time. Wetland forests along rivers, estuaries and coastal areas also give runoff from precipitation (which eventually gets into rivers) a place to spread out, serving as natural retention basins. Wetland forests act like sponges soaking and absorbing a lot of water down into the ground and then releasing it slowly over time. As much as 2.3 million litres of water is absorbed per hectare, depending on the nature of the soil. Forests hold the water and release it slowly. When forests are cleared or destroyed, all the rainwater gets into rivers at a relatively rapid time, resulting in flash floods. The concentration of water into the main river channel over a much shorter period of time dramatically increases flooding. It is vital for engineers and all scientists to work with natural systems rather than against them. In this respect, the JPS Malaysia has initiated the mandatory Manual for Environmentally Friendly Drainage for all development projects, indicating an all-important change of mindset from conventional engineering approach to a more comprehensive multi¬disciplinary approach that taps on the expertise of all disciplines. Penerbit Ustara Ali, Juhary A Rahman, Badruddin Mohamed, Zahari Zainuddin, Nizamuddin 2002 Book Section PeerReviewed application/pdf en http://eprints.utm.my/2532/1/Employing-2002-Chan.pdf Chan, Ngai Weng and Ibrahim, Ab. Latif and Kung, Hsiang-te and Liu, Pin-Shuo (2002) Employing nature to combat floods: some experiences from Malaysia. In: Disaster Management : Strengthening the National Security Capabilities. Penerbit Ustara, Alor Setar, pp. 143-158.
spellingShingle Q Science (General)
GE Environmental Sciences
Chan, Ngai Weng
Ibrahim, Ab. Latif
Kung, Hsiang-te
Liu, Pin-Shuo
Employing nature to combat floods: some experiences from Malaysia
title Employing nature to combat floods: some experiences from Malaysia
title_full Employing nature to combat floods: some experiences from Malaysia
title_fullStr Employing nature to combat floods: some experiences from Malaysia
title_full_unstemmed Employing nature to combat floods: some experiences from Malaysia
title_short Employing nature to combat floods: some experiences from Malaysia
title_sort employing nature to combat floods: some experiences from malaysia
topic Q Science (General)
GE Environmental Sciences
url http://eprints.utm.my/2532/
http://eprints.utm.my/2532/1/Employing-2002-Chan.pdf