Researchers at the University of Liege have published a multi-disciplinary research paper which makes it possible to estimate the damage that could be caused by variations in discharge of the river Meuse between now and 2100. The publication followed the AMICE project, an original, international, interregional and innovative collaboration project on the river and its river basin. To get a better grasp of the problem, the scientists from the University of Liege combined climatology, hydrology, hydraulics and urban planning, and focussed their research on the current considerations of the public authorities and the IPCC (Intergovernmental Panel on Climate Change). Their conclusions are clear: there needs to be better management of urbanization to limit the upward trend in considerable flood-related damage. It is estimated that, in Wallonia, the level of the river during a one hundred-year flood peak will increase by an average of 60 centimeters between now and 2050 and by 130 centimeters between now and 2100, creating a risk of flooding. Conversely, situations of prolonged low water levels are predicted for the drier months. The researchers have created an impressive chain of numerical models and relevant theories in the public interest.  

Influenced by global warming and uncontrolled urban planning, flooding and the damage it causes have increased steadily, both in terms of frequency and intensity.  Predictions about flooding by rivers do not leave any margin for optimism. The river Meuse, which flows through Wallonia over a distance of 185 km, is no exception. The river flows through 19 of our communes which, to a greater or lesser degree, are exposed to a very high risk of flooding that is likely to increase over the coming years. In fact it is estimated that in Wallonia, the level of the river during a one hundred-year flood, will increase by 60 centimeters between now and 2050, and by 130 centimeters between now and 2100, leading to a risk of flooding. Conversely, situations of prolonged low water levels are predicted for the drier months.

A multi-disciplinary research project conducted at the HECE unit (Hydraulics in Environmental and Civil Engineering) of the Faculty of Applied Sciences of ULg aims to establish the risks of flooding in our region with the aid of a new predictive model. It extends into the future as far as 2100, and by developing several possible scenarios, estimates the damage that might be caused by such disasters. In order to accurately reflect a situation that is much more than a simple question of hydrology, and which depends on many factors, the study also integrates considerations such as climate, geography, hydraulics and urban planning, because although flooding is a natural phenomenon, the material damage it causes also depend on the exposure of zones in areas prone to flooding, and therefore involves political decisions as well.

The timing of the study could not be better. At a time when natural catastrophes are making headlines, it is now, more than ever, time to rething the systems of flood-protection such as dams, dykes… which in some cases are fast becoming obsolete. However, a systematic reconstruction of such infrastructures is economically unthinkable. Such costs could be avoided however. For this to happen, a complete rethink of planning in Wallonia (which defines the exploitable urban areas) and a restriction on building in areas prone to flooding will be neccessary.

Cross-border harmonization

There is an increasing awareness of the global, or at least the inter-regional character of the risk of natural catastrophes, and the need for management of this risk to be shared by the actors concerned. The first step in sharing this risk begins with a harmonization of observations and ideas about our surrounding environment. This article is the result of research that aims to adopt the above approach to the problem, explains Benjamin Dewals, lecturer in hydraulic engineering at ULg. “This publication follows the AMICE project which focussed on the entire Meuse river basin. The originality of this approach was to enable teams of scientists and managers from each country concerned to work together (France, Germany, Wallonia, Flanders and Holland, Editor’s note.). In an overall context, the project aimed to assess all the consequences of flooding and one hundred-year flood peaks between now and 2100, by taking a coherent account of the impact of climate on a basin-wide scale. For this to be possible it was neccessary for parties involved to work together.”

A. Beckers, B. Dewals, S. Erpicum, S. Dujardin, S. Detrembleur1, J. Teller, M. Pirotton, P. Archambeau Contribution of land use changes to future flood damage along theriver Meuse in the Walloon region, Natural Hazards and Earth System Sciences, 2013 (http://www.nat-hazards-earth-syst-sci.net/13/2301/2013/nhess-13-2301-2013.html)