Terverun (Belgium)

The study area of this project is Tervuren Municipality, Belgium, which is depicted in Figure 1. The municipality spans an area of 33.62 km2 with approximately 13.2% of the area is developed into an urban area (Flemish Government, 2022). A large area in Tervuren is at risk of urban fluvial and pluvial floods (HNL, 2023; Flemish Government, 2023). In 2005, the stormy weather caused a devastating flood in Tervuren which induced further problems such as reduced vehicle speeds to walking pace and mixed wastewater from the sewers entering a watercourse in periods of heavy rainfalls, as depicted in Figure 2.

Currently, Tervuren has a moderate annual rainfall of approximately 780 mm, as measured by the Royal Meteorological Institute at Uccle Station (Hamdi, et al, 2010). Climate change is expected to increase precipitation extreme which potentially exacerbate urban pluvial flooding in Tervuren. Figure 3 depicts the 20-years storm event in Tervuren under current and 2050 climate projection scenarios based on IDF Ukkle (Delbeke, 2001), which shows the increased peak and total volume of 2050 climate projection rainfall. On the other hand, Tervuren has a complex sewer system containing 3560 junctions, 28 storage units, and 33 outfalls.