The experiment

We want to go where no researcher has gone before and test real trees with extreme waves in the massive Delta Flume at Deltares. In this research we will address the most urgent knowledge gaps on the role of trees in flood risk reduction. Do floodplain forests in our rivers limit over-topping of levees and embankments? Did the presence of mangroves protect coastal communities during the Asian tsunami? These aspects can yet only be modeled, estimated and predicted to a limited degree, since prototype measurements under extreme conditions and in a controlled environment, are not available. This research will unravel whether the protective power of trees is fact or fiction.

To better quantify the effect of willow trees and mangroves on wave height reduction we will place 40-60 meters of willow trees in the world’s largest wave flume facility, the Delta Flume at Deltares. The Delta Flume is 300 meters long, 5 meters wide and has a depth of 7.5-9 meters. Wave heights of up to 4m (Hs=2.2m) can be generated, which allows the testing of vegetation and vegetation models at real scales for extreme wave conditions.