From Meteorological Forecasting to Floodplain Forecasting for the Protection of Populations in Urban and Peri-Urban Areas

Abstract

The best measure to protect residents in flood areas remains anticipating relief efforts. This requires early availability of reliable spatial and temporal information on future flood risk. We will present 2 case studies on which flood forecasting and warning systems have been set up. These systems all have the objective of translating rainfall forecasts into flood risk for the safety of people, however we will see that the flood risk information can be different depending on the context and the need of each administrator. These systems have been set up in the MIKE OPERATIONS platform to import and process rainfall data, carry out hydraulic simulations and provide flood risk information adapted to each user.

The first case studies is about the flood forecast system of Pointe à Pitre developed for the CAP Excellence where the real time system can show a map with red point where the network can overflow in the next 24 h gives the flood risk information. The second case studies concern the flood forecast system developed for the SIAVHY which integrates a 1D/2D model running in real time with rainflow model based on spatial rainfall forecast. The flood risk information is a flood map with discretization of the water depth on the flood area.

The main objective of all these systems is to provide an understanding of the expected risk for better anticipation, based on the transformation of the rainfall forecast information.