THE USE OF HEC-RAS MODELLING IN FLOOD RISK ANALYSIS
IOSUB MARINA1, MINEA I., HAPCIUC OANA , ROMANESCU GH.
ABSTRACT. – The use of HEC-RAS modelling in flood risk analysis. The fact that, in the Ozana drainage basin, most of the people have built their homes in the river valley, determines that a study focused on identifying the areas exposed to hydrological risk is vital, mostly in the development decisions for villages and in the creation of management plans for emergency situations. This study analyses the mapping methodology of the flood prone areas in the middle and lower sector of the Pluton river, which is a tributary of Ozana river, in its upper sector. In order to correctly draw the flood risk maps, the HEC-RAS method has been used, together with the HEC-GeoRAS extension, in ArcGIS. The results that have been obtained, correlate with the field situation in a very high proportion: for a 1% occurance flood, almost 123 households have been damaged, and according to the simulation, a number of 147 buildings have been damaged, therefore other probabilities (that overcome the 1% situation) can be used for similar simulations.
Keywords: HEC-RAS, risk, flood, flood band, Ozana