Use of HEC-RAS and HEC-HMS models with ArcView for hydrologic risk management

The paper discusses how the well known USACE HEC models, RAS and HMS, are fullyintegrated within the decision support system of the Romagna River Basins in order to predict flood effects.The models are fully available from the web and cope with such a variety of problems as rainfall-runoffmodeling, river and civil works hydraulics, and the mapping of hydraulic hazard. The paper illustrates themethodology followed to integrate existing topographic and hydrologic data, calibrate both hydrologic andhydraulic models, and produce maps directly usable in land planning. The paper stresses the organizationalproblems involved in the development of such a decision support system, and sketches the main issues inpipelining general planning analysis and river training and management design, in order to achieve a fullyself-updating decision support system which feeds back analysis results to design evaluations and againupdated information from developed works to the prediction models.