The Siret Basin, situated in the east of the Carpathians mountains in Romania, is the third largest catchment of any Danube tributary and extends over 28,000 square kilometers.
The Siret flows from its source in Ukraine through Romania, joined along the way by the main tributary rivers – Suceava, Moldova, Bistrita, Trotus, Barlad and Buzau. Several major reservoirs and an extensive network of dykes are critical flood defences.
A major flood event in 2005 caused many fatalities and the evacuation of thousands of people from their homes. Damages of €500 million were estimated for losses to crops alone. The flood burst through dykes and inundated built-up areas by more than 3 m depth. The peak flow was recorded at 4,650 m3/s.
Other significant flood events have occurred in the last 40 years and these floods, together with the need to meet the requirements of the EU Flood Directive, were key drivers for a major flood management project awarded by the Water Directorate of Siret.
The project improves the local capabilities in flood risk management and includes extensive flood mapping which has been generated using our software.
The Flood Modeller 1D solver has been used to model over 700 km of main river and major tributaries. In rural areas, the floodplain has been modelled using extended sections in our 1D solver, whereas in urban areas a linked 2D model has been used for the floodplain. There are over 68 km of coupled 1D and 2D models covering the urban flood-prone areas.
Our software has been used to bring together the topographic and bathymetric survey information with the aerial photography and vector data to help build the 1D and 2D models and process results. Time savings of 4 weeks have been achieved through the use of our software to:
- Extend 1D cross-sections across the rural floodplain.
- Generate 1D ‘spill’ unit data sets to represent embankment crests (including using our helpful spill generator which searches for the highest point near to the nominal embankment top polyline).
- Automatically generate the link lines that connect the 1D and 2D model domains.
- Generate flood extents and depth grids for both the 1D and 2D model outputs.
The modelling has helped to develop a greater understanding of the flood risks, flooding mechanisms, potential climate change and urbanisation effects and response options.