Changing landscapes, not global warming, to blame for increased flood risk

Jan 21, 2014

This timely article considers the findings of an international report on flood risk, and the possible linkage with climate change/global warming and an increase in global and regional flooding.

Major flood events occur around the world every year, but with international loss databases documenting increased incidents of flooding, more material loss and greater fatality rates, are these events on the increase, and are they getting worse?

A new study published in Hydrological Sciences Journal examines the key reasons for increasing frequency and severity of floods; considering whether this is due to improved reporting by the media, an increasing and expanding global population, or whether climate change is the crucial factor.

The authors combine the outcomes of the IPCC Special Report on "Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation" (SREX report) with more recent research to give a rounded view of the cost of flooding (both human and material), the causes of increased flood risk and predictions of future global flooding patterns.

Studies have shown that there is a clear link between population density and flooding. Currently 800 million humans are living in areas vulnerable to flooding. This is predicted to rise by a further 140 million during 21st Century as we see continued economic and population growth. At the same time reduction of woodland, changing river flow and the urbanisation of flood plains will increase flood risk in many regions.

The SREX report established a link between the human impact on the global landscape and occurrences of heavy precipitation leading to greater flood risk, and predicts an increase in rain generated flooding this Century. At the same time the report concluded that there was a lack of research identifying, in a persuasive way, an influence of anthropogenic climate change on global river flooding.

Whilst scientists recognise that climatic factors such as atmospheric water vapour, evapotranspiration, snowmelt, temperature sequences, ground water and soil moisture content can all contribute to flooding; further long term study of regional flood patterns is needed to fully understand how a change in the climate could alter these climatic factors and impact on future .

Furthermore, whilst and greenhouse gas emissions are strongly linked to flooding, the relationship is very complex, and to date neither empirical analysis nor data modelling has been able to accurately describe the connections.

The key message of this research is that:

"The scientific community needs to emphasize that the problem of flood losses is mostly about what we do on or to the landscape and that will be the case for decades to come."

The authors urge governments, scientists, engineers and citizens to use practical precautionary strategies to limit regional flooding sooner rather than later, because conclusive scientific evidence linking and flooding will be a long time coming.

Explore further: Pipeline that leaked wasn't equipped with auto shut-off

More information: "Flood risk and climate change: global and regional perspectives", by Z. W. Kundzewicz et al., Hydrological Sciences Journal, Vol. 59, No. 1, 1-28, published by Routledge, Taylor & Francis.

Related Stories

Assessing the impact of climate change on a global scale

Dec 16, 2013

Thirty research teams in 12 different countries have systematically compared state-of-the-art computer simulations of climate change impact to assess how climate change might influence global drought, water scarcity and river ...

Recommended for you

Pipeline that leaked wasn't equipped with auto shut-off

May 24, 2015

The pipeline that leaked thousands of gallons of oil on the California coast was the only pipe of its kind in the county not required to have an automatic shut-off valve because of a court fight nearly three ...

California farmers agree to drastically cut water use

May 23, 2015

California farmers who hold some of the state's strongest water rights avoided the threat of deep mandatory cuts when the state accepted their proposal to voluntarily reduce consumption by 25 percent amid ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.