How should flood risk assessments be done in a changing climate?

Aug 04, 2014

Growing consensus on climate and land use change means that it is reasonable to assume, at the very least, that flood levels in a region may change. Then why, ask Rosner et al. in a new study, do the dominant risk assessment techniques used to decide whether to build new flood protection infrastructure nearly always start with an assumption of "no trend" in flood behavior?

In an argument grounded in an analysis of the inherent limitations of statistical analyses, the authors suggest that researchers' typical starting assumption that flood behavior is not changing—even in the face of suspected trends in extreme events and knowledge of how difficult such trends are to detect—causes water managers to undervalue benefits, opening the door to unnecessary losses down the line.

When researchers assume no trend, statistical errors could cause them to overlook of the risks of underpreparing for changing flood conditions. Often, potential flood damage due to underpreparedness far exceeds the potential cost of overinvesting in protection infrastructure. Flipping the process around, starting with an assumption that a change in is occurring, would give critical attention to the risk of underestimating future floods, rather than only considering the risk of wasting money on unneeded infrastructure.

The authors propose a method of that starts with the null hypothesis of "no trend" but that explicitly assesses the effect of statistical uncertainties that may cause them to misidentify real trends and the damages those trends might produce.

Explore further: New approach needed to deal with increased flood risk

More information: Rosner, A., R. M. Vogel, and P. H. Kirshen (2014), A risk-based approach to flood management decisions in a nonstationary world, Water Resour. Res., 50, 1928, DOI: 10.1002/2013WR014561

add to favorites email to friend print save as pdf

Related Stories

New approach needed to deal with increased flood risk

Apr 17, 2014

Considering the impacts of climate change on flood risk may not be effective unless current risk is managed better, according to new research from the University of Bristol published today in the Journal ...

Flood fear has temporary effect on property prices

Jul 02, 2014

The stigma of buying in a flood-prone suburb after the 2011 Brisbane floods was short-lived for middle and high-value homes with property prices rebounding within 12-months, a QUT study has found.

River beds on the move: Shifting flood risk?

Apr 24, 2013

(Phys.org) —A detailed study of shifting river beds, conducted by researchers at the University of St Andrews, could hold the key to more accurate flood prevention.

European flood risk could double by 2050

Mar 02, 2014

Losses from extreme floods in Europe could more than double by 2050, because of climate change and socioeconomic development. Understanding the risk posed by large-scale floods is of growing importance and will be key for ...

Is the US National Flood Insurance Program affordable?

Jul 17, 2014

There is often tension between setting insurance premiums that reflect risk and dealing with equity/affordability issues. The National Flood Insurance Program (NFIP) in the United States recently moved toward ...

Recommended for you

Putting a value on what nature does for us

Sep 12, 2014

A new online resource, developed by researchers at the University of Cambridge in collaboration with other organisations based in Cambridge, helps those in both the public and private sector see how changes ...

User comments : 0