The University of Southampton
University of Southampton Institutional Repository

Global evidence that deforestation amplifies flood risk and severity in the developing world

Global evidence that deforestation amplifies flood risk and severity in the developing world
Global evidence that deforestation amplifies flood risk and severity in the developing world
With the wide acceptance of forest-protection policies in the developing world comes a requirement for clear demonstrations of how deforestation may erode human well-being and economies. For centuries, it has been believed that forests provide protection against flooding. However, such claims have given rise to a heated polemic, and broad-scale quantitative evidence of the possible role of forests in flood protection has not been forthcoming. Using data collected from 1990 to 2000 from 56 developing countries, we show using generalized linear and mixed-effects models contrasted with information-theoretic measures of parsimony that flood frequency is negatively correlated with the amount of remaining natural forest and positively correlated with natural forest area loss (after controlling for rainfall, slope and degraded landscape area). The most parsimonious models accounted for over 65% of the variation in flood frequency, of which nearly 14% was due to forest cover variables alone. During the decade investigated, nearly 100 000 people were killed and 320 million people were displaced by floods, with total reported economic damages exceeding US$1151 billion. Extracted measures of flood severity (flood duration, people killed and displaced, and total damage) showed some weaker, albeit detectable correlations to natural forest cover and loss. Based on an arbitrary decrease in natural forest area of 10%, the model-averaged prediction of flood frequency increased between 4% and 28% among the countries modeled. Using the same hypothetical decline in natural forest area resulted in a 4–8% increase in total flood duration. These correlations suggest that global-scale patterns in mean forest trends across countries are meaningful with respect to flood dynamics. Unabated loss of forests may increase or exacerbate the number of flood-related disasters, negatively impact millions of poor people, and inflict trillions of dollars in damage in disadvantaged economies over the coming decades. This first global-scale empirical demonstration that forests are correlated with flood risk and severity in developing countries reinforces the imperative for large-scale forest protection to protect human welfare, and suggests that reforestation may help to reduce the frequency and severity of flood-related catastrophe
1354-1013
2379-2395
Bradshaw, Corey J. A.
909e397d-4fb2-4647-b6a3-4680002bf236
Sodhi, Navjot S.
3dcb4076-fe05-4a62-854e-ac587b5db377
Peh, Kelvin S.-H.
0bd60207-dad8-43fb-a84a-a15e09b024cc
Brook, Barry W.
7a3c9230-5ad5-4938-b38e-5ba2b47c4c5d
Bradshaw, Corey J. A.
909e397d-4fb2-4647-b6a3-4680002bf236
Sodhi, Navjot S.
3dcb4076-fe05-4a62-854e-ac587b5db377
Peh, Kelvin S.-H.
0bd60207-dad8-43fb-a84a-a15e09b024cc
Brook, Barry W.
7a3c9230-5ad5-4938-b38e-5ba2b47c4c5d

Bradshaw, Corey J. A., Sodhi, Navjot S., Peh, Kelvin S.-H. and Brook, Barry W. (2007) Global evidence that deforestation amplifies flood risk and severity in the developing world. Global Change Biology, 13 (11), 2379-2395. (doi:10.1111/j.1365-2486.2007.01446.x).

Record type: Article

Abstract

With the wide acceptance of forest-protection policies in the developing world comes a requirement for clear demonstrations of how deforestation may erode human well-being and economies. For centuries, it has been believed that forests provide protection against flooding. However, such claims have given rise to a heated polemic, and broad-scale quantitative evidence of the possible role of forests in flood protection has not been forthcoming. Using data collected from 1990 to 2000 from 56 developing countries, we show using generalized linear and mixed-effects models contrasted with information-theoretic measures of parsimony that flood frequency is negatively correlated with the amount of remaining natural forest and positively correlated with natural forest area loss (after controlling for rainfall, slope and degraded landscape area). The most parsimonious models accounted for over 65% of the variation in flood frequency, of which nearly 14% was due to forest cover variables alone. During the decade investigated, nearly 100 000 people were killed and 320 million people were displaced by floods, with total reported economic damages exceeding US$1151 billion. Extracted measures of flood severity (flood duration, people killed and displaced, and total damage) showed some weaker, albeit detectable correlations to natural forest cover and loss. Based on an arbitrary decrease in natural forest area of 10%, the model-averaged prediction of flood frequency increased between 4% and 28% among the countries modeled. Using the same hypothetical decline in natural forest area resulted in a 4–8% increase in total flood duration. These correlations suggest that global-scale patterns in mean forest trends across countries are meaningful with respect to flood dynamics. Unabated loss of forests may increase or exacerbate the number of flood-related disasters, negatively impact millions of poor people, and inflict trillions of dollars in damage in disadvantaged economies over the coming decades. This first global-scale empirical demonstration that forests are correlated with flood risk and severity in developing countries reinforces the imperative for large-scale forest protection to protect human welfare, and suggests that reforestation may help to reduce the frequency and severity of flood-related catastrophe

This record has no associated files available for download.

More information

Published date: 2007
Organisations: Faculty of Natural and Environmental Sciences

Identifiers

Local EPrints ID: 353675
URI: http://eprints.soton.ac.uk/id/eprint/353675
ISSN: 1354-1013
PURE UUID: 4ba8ea29-ff28-45e0-8f5e-74e77feb2243
ORCID for Kelvin S.-H. Peh: ORCID iD orcid.org/0000-0002-2921-1341

Catalogue record

Date deposited: 13 Jun 2013 13:01
Last modified: 15 Mar 2024 03:44

Export record

Altmetrics

Contributors

Author: Corey J. A. Bradshaw
Author: Navjot S. Sodhi
Author: Barry W. Brook

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×