Flood risk assessment for informal settlements
Autor: | Maurizio Giugni, Maria Elena Topa, Elinorata Mbuya, Iunio Iervolino, Fatemeh Jalayer, F. De Paola, Gaetano Manfredi, Paolo Gasparini, Alphonce Kyessi, R. De Risi |
---|---|
Přispěvatelé: | DE RISI, Raffaele, Jalayer, Fatemeh, De Paola, F., Iervolino, Iunio, Giugni, M., Topa, M. E., Mbuya, E., Kyessi, A., Manfredi, Gaetano, Gasparini, P. |
Rok vydání: | 2013 |
Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences Flood myth business.industry Flooding (psychology) Environmental resource management 1. No poverty 0207 environmental engineering Sample (statistics) 02 engineering and technology 01 natural sciences Hazard Civil engineering Fragility 13. Climate action Flood risk assessment Natural hazard 11. Sustainability Earth and Planetary Sciences (miscellaneous) Portfolio Environmental science 020701 environmental engineering business 0105 earth and related environmental sciences Water Science and Technology |
Zdroj: | Natural Hazards |
ISSN: | 1573-0840 0921-030X |
DOI: | 10.1007/s11069-013-0749-0 |
Popis: | The urban informal settlements are particularly vulnerable to flooding events, due to both their generally poor quality of construction and high population density. An integrated approach to the analysis of flooding risk of informal settlements should take into account, and propagate, the many sources of uncertainty affecting the problem, ranging from the characterization of rainfall curve and flooding hazard to the characterization of the vulnerability of the portfolio of buildings. This paper proposes a probabilistic and modular approach for calculating the flooding risk in terms of the mean annual frequency of exceeding a specific limit state for each building within the informal settlement and the expected number of people affected (if the area is not evacuated). The flooding risk in this approach is calculated by the convolution of flooding hazard and flooding fragility for a specified limit state for each structure within the portfolio of buildings. This is achieved by employing the flooding height as an intermediate variable bridging over the fragility and hazard calculations. The focus of this paper is on an ultimate limit state where the life of slum dwellers is endangered by flooding. The fragility is calculated by using a logic tree procedure where several possible combinations of building features/construction details, and their eventual outcome in terms of the necessity to perform structural analysis or the application of nominal threshold flood heights, are taken into account. The logic tree branch probabilities are characterized based on both the orthophoto recognition and the sample in situ building survey. The application of the methodology is presented for Suna, a sub-ward of Dar es Salaam City (Tanzania) in the Msimbazi River basin having a high concentration of informal settlements. |
Databáze: | OpenAIRE |
Externí odkaz: |