Landuse change and future flood risk: an integrated and multi-scale approach

Benjamin Dewals, Martin Bruwier, Yann Peltier, Pierre Archambeau, Sébastien Erpicum, Ahmed Mustafa, Ismaïl Saadi, Philippe Orban, Mario Cools, Alain Dassargues, Jacques Teller, Michel Pirotton

Tuesday 30 june 2015

16:15 - 16:30h at South America (level 0)

Themes: (T) Flood risk management and adaptation, (ST) Flood risk assessment

Parallel session: 7J. Floodrisk - Assessment

The goal of this research is a better understanding of the complex interactions between landuse change and future flood risk. Landuse change is assumed to be mainly driven by population growth and socio-economic factors. It affects future flood risk by altering catchment hydrology as well as vulnerability in the floodplains; but the feedback effect of (the perception of) changes in flood hazard on landuse evolution is also considered. The research is based on a chain of modelling tools, which represent parts of the natural and human systems, including: • stochastic landuse change modelling, • traffic modelling, as an onset for the estimation of indirect flood damage, and Land-Use and Transport Interactions models (LUTI), • continuous hydrological modelling, forced by precipitation and temperature data disturbed according to climate change scenarios, • efficient hydraulic modelling of inundation flow in the floodplains. Besides reproducing a broad spectrum of processes, the modelling approach spans over multiple scales, from the regional or catchment level down to the floodplain and building levels. This distinctive feature is reflected both within the individual models and through their combination involving fine-scale detailed analyses (or data) embedded within coarser models at a broader level. The developed models and methodology will be validated and demonstrated based on a real-world case study corresponding to a Belgian sub-basin (river Ourthe) of the international Meuse basin. The scientific approach developed within the project includes many original aspects, such as: • coupling of Cellular Automata and Agent-Based models for landuse change modelling, incorporating different built-up densities, • disaggregated nature of large scale agent-based micro-simulation for traffic modelling, enabling higher temporal and spatial resolutions compared to more conventional models, • new shallow-water model with porosity, based on a complete set of depth-dependent storage and conveyance porosities.