Author(s): Gunnar G. Tomsson; Thorbergur S. Leifsson; Olof R. Karadottir; Olafur Sigurdsson; Laufey B. Hannesdottir; Haraldur Olafsson; Oli Gretar Blondal Sveinsson
Linked Author(s):
Keywords: Flood estimates; Flood prediction; Weather model; Atmospheric model; Probable maximum flood; Flood discharge correction; Thjorsa-Tungnaariver basin; Iceland
Abstract: A flood analysis system has been set up for the Thjorsa-Tungnaa river basin in South Iceland. Simulation of weather during flood events is made with the MM5 atmospheric model. Snowmelt is based on energy and mass balanced model. Routing of floods through the river basin is made with the HEC-HMS system. Calibration of the model is made with data from two historical floods. The model is used to correct historical discharge records for the influence of several storage reservoirs and diversion schemes implemented in the area over the last 35 years. Frequency analysis of the corrected discharge records results in return periods for natural floods in the area. By use of the weather model, an estimate is obtained of the maximum precipitation that is physically realizable in the area. This data together with the flood analysis system is used to generate an estimate for probable maximum floods within the entire river basin.
Year: 2005