University of Twente Student Theses
Flood hazard assessment in a flood Prone urban area using hydrodynamic Models and gis techniques case of study In Pergamino, Argentina
Mattos Gutierrez, Silvia Roxana (2010) Flood hazard assessment in a flood Prone urban area using hydrodynamic Models and gis techniques case of study In Pergamino, Argentina.
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| Abstract: | use of hydrodynamic models to assess flood events and levels has been applied all over the world for already many years. However, in developing countries flood hazard assessments has to overcome limitations of the information and lack of technical assessment. This work focuses on the flood hazard assessment in a flat area of Pergamino (Argentina) using two hydrodynamic models with the support of GIS techniques. The research attempts the evaluation of flood characteristics of the river using 1D model HecRas and the assessment of the flood propagation in the urban area using model Flo-2D. The work is based on data collected from previous studies and validation values taken during fieldwork. HecRas model allowed the calibration and validation of the rating curve for the only city liminimeter (Florencio Sanchez). The wave celerity and the travel time of the wave were also calculated. The limnigraph stations Alfonzo y Urquiza located upstream and downstream of the urban area were evaluated as source of data for the modelling process, however, a backwater effect found in the area of Alfonzo plus the scarcity of topographic information were determinant to restrict their application. A DTM generated from points measured during a topographic survey was used as main data. Major attention is place in the construction of the DTM and advices exposed. The three origin of flood events were simulated: a) Heavy rainfall, b) Overflow from the channel (riverine event) and c) the combination of both events for 10 years of return period. During the simulations the volume conservation and numerical stability were evaluated, and a process considering changes in the numerical stability criterion was performed. Furthermore a comparison between the maximum simulated flow depth for a past event and the values recorded locally was attempt. The results showed a properly performance of Hec Ras model for the river channel in steady flow conditions, a hazard map with the water depths under the levees have failure problems was presented. Furthermore, the simulations with Flo-2D allowed the generation of flood hazard maps as first approach or draft for the city. In the case of scenario a), the three hours total rainfall did not generate high level of flood hazard, a medium hazard level was predominant in the case of scenario b) and c). The comparison between the simulated maximum flow depth for a past event and the values recorded in Pergamino showed the need to improve the data collection with instrumentation in a systematic manner to allow further validations. Key words: Flood hazard, hydrodynamic models, Hec Ras, Flo-2D, Pergamino city. |
| Item Type: | Essay (Master) |
| Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
| Programme: | Geoinformation Science and Earth Observation MSc (75014) |
| Link to this item: | https://purl.utwente.nl/essays/90767 |
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