Hurricanes Harvey and Irma demand a Dutch approach

In the past weeks, hurricanes Harvey and Irma have caused vast damages. Researchers at the Vrije Universiteit study the consequences of storms in coastal areas and have analysed the economic value of Dutch approaches to limit such damages in the future.

09/11/2017 | 1:02 PM

Damages caused by the two recent hurricanes will easily amount to billions of dollars. Researchers from the Vrije Universiteit have been collaborating for years with American colleagues at MIT, Princeton and Texas A& to develop solutions for coastal cities and other areas, such as storm surge barriers in combination with better evacuation plans and insurance policies.

Both Harvey and Irma are hurricanes of the highest categories, with extreme wind speeds. They could be called ‘perfect storms’ bringing threat from two sides. On the one hand water is pushed up the shore by the strong winds. On the other, both hurricanes cause extreme amounts of local precipitation.

Flood damage
Professor in Water and Climate Risks Jeroen Aerts (VU-IVM) on Houston: 'The city of Houston has had multiple warnings, following hurricane Ike and more recent floods in the area. Damages from hurricane Harvey to roads and houses will most likely be more than 10 billion dollars, and damages to the regional economy could be as high as 20 billion dollars.'

In a recent publication, climate researcher Philip Ward (VU-IVM) shows that on a global level the economic gains from building and strengthening dikes are much higher than the costs. 'We know that because of climate change and population growth, the economic damages from floods in vulnerable areas will increase the next decades. However, research shows that these damages can be reduced below the current level, as long as we keep investing in protective measures.'

Combination of measures
In the US, adaptation measures to the expected increase in flood events will firstly consist of developing better evacuation plans, regulating construction, and developing better insurance policies. Aerts: “These are the kinds of measures that the US are familiar with and that fit the culture of taking responsibility. At the same time, researchers from the Vrije Universiteit are working with their American colleagues on more Dutch-minded solutions, such as the construction of dikes, storm surges, and periodically raising beaches with sand supplementation. Although these solutions are more expensive, if you compare their cost to the economic interests of a city like Houston and the damages that a hurricane like Harvey has caused, it may be very worthwhile to consider such investments'. Ward: 'Dikes will give a great economic return, also outside of the Netherlands.' This item is largely based on a news item (in Dutch) published by the Vrije Universiteit Amsterdam.

Click here for more information on the study by Philip Ward and colleagues on the future costs and benefits of river-flood protection.