MERLIN: a flood hazard forecasting system for coastal river reaches

Abstract

[Abstract:] This study presents MERLIN, an innovative flood hazard forecasting system for predicting discharges and water levels at flood prone areas of coastal catchments. Discharge forecasts are preceded by a hindcast stage. During this stage, the hydrological models assimilate soil moisture and hydro-meteorological observations to evaluate soil infiltration capacities at the beginning of the discharge forecast. Predicted discharges are converted to water-level forecasts using the hydraulic model Iber+, a GPU-parallelized bidimensional flow model. Hydraulic models also assimilate tidal-level forecasts in order to define the boundary conditions of the models. The performance of MERLIN was evaluated over 4 months at three coastal catchments of 4.95, 16.96, and 83.9 km2. Forecasted discharges and water levels presented a good fit to observed values, especially at the larger catchments, which confirmed the potential utility of the presented system.