MSc Thesis Title: Parameter sensitivity analysis of hydrological flood event simulation & hydraulic wave simulation in a small hydrological basin
Tuesday 23 October 2018, at:13:00, Venue: Hall Κ3.A17
Examination Committee
- Professor Ioannis Tsanis (advisor)
- Professor Constantinos Chrysikopoulos
- Dr. Aristeidis Koutroulis
Abstract:
In the present Master Science thesis, a flash flood event is simulated occurring in the Almyrida basin, in western Crete. Through the hydrological analysis of the flash flood event and the modeling of the hydraulic wave, the aim is to assess the impacts on the small hydrological basin, via a combination of HEC software.
The simulation of the rainfall event occurs with the hydrological HEC-HMS 4.2.1 model. Precipitation data are input into a grid, while hydrological parameters are input into each grid cell. The hydrological parameters of the basin, for which data are available, are calculated, while the remaining parameters are calibrated through a bibliographic review. Sensitivity analysis of the model is carried out, and it is determined which of the calibrated parameters change the time of appearance of peak discharge. At the same time, it is checked which parameters affect the magnitude of peak discharge. Parameter calibration criterion is to verify the model, measuring 2m of water depth in a cross section checked after the flood.
The downstream analysis of the Almyrida stream of approximately 960 m, is carried out with the hydraulic 1D HEC-RAS 5.0.3 flood simulation model, as well as a combined hydraulic 1D/2D model, the 1D/2D HEC-RAS 5.0.3 model, for the needs of which a high resolution 5m x 5m Digital Terrain Model (DTM) is used. The simulation models determine the flood extent, the depth and velocity of the flood wave in the stream’s cross sections, while comparing their results.
Through the implementation of modeling with HEC software, the flood impacts of the flash flood event are highlighted, and some suggestions are proposed as well to limit the risks, resulting in particularly interesting conclusions.
Keywords: flash flood event, HEC-HMS, 1D HEC-RAS, 1D/2D HEC-RAS.
