A DISTRIBUTED MODEL FOR REAL-TIME FLOOD FORECASTING USING DIGITAL ELEVATION MODELS

A distributed model for real-time rainfall-runoff simulation during floods is presented. The model, called Distributed Basin Simulator (DBSIM) is based on the detailed topographical information provided by Digital Elevation Models (DEM). Basin representation uses the rectangular grid of the DEM. Soil properties, input data and state variables are also represented as data layers using the same scheme. Distributed rainfall input is used to map the topographically driven evolution of saturated areas as the storm progresses. The model applies a kinematic model of infiltration to evaluate local runoff generation in grid elements and accounts for lateral moisture flow between elements and surface flow routing in a simplified manner. Model performance is evaluated through sensitivity analyses and an exercise of model calibration and verification.