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Hydrological and hydraulic modelling applied to the mapping of flood-prone areas

Monte, Benício Emanoel Omena; Costa, Denis Duda LU ; Chaves, Mahelvson Bazilio; de Oliveira Magalhães, Louis and Uvo, Cintia B. LU (2016) In Revista Brasileira de Recursos Hidricos 21(1). p.152-167
Abstract

Overbank flooding caused by historically high flows, such as that in the Rio Mundaú watershed (lying between the states of Alagoas and Pernambuco) in 2010, has been the cause of widespread damage. The purpose of work described in this paper was to propose a mapping of areas liable to flooding in the township of Rio Largo (Alagoas) in the Rio Mundaú watershed by means of an “off-line” coupling of the hydrological/hydraulic models (MGB-IPH/ HEC-RAS), through consideration of extreme floods with different return periods for discharge. The hydrological model had a parameterization appropriate for extreme floods, using as input rainfall data with different return periods. Calibration and validation of the hydrological model were adequate in... (More)

Overbank flooding caused by historically high flows, such as that in the Rio Mundaú watershed (lying between the states of Alagoas and Pernambuco) in 2010, has been the cause of widespread damage. The purpose of work described in this paper was to propose a mapping of areas liable to flooding in the township of Rio Largo (Alagoas) in the Rio Mundaú watershed by means of an “off-line” coupling of the hydrological/hydraulic models (MGB-IPH/ HEC-RAS), through consideration of extreme floods with different return periods for discharge. The hydrological model had a parameterization appropriate for extreme floods, using as input rainfall data with different return periods. Calibration and validation of the hydrological model were adequate in drainage areas larger than 1500 km2, but were less acceptable in headwater drainage areas where different geology and soil cover gave rise to surface runoff. The hydraulic model showed good agreement with point observations of flood levels in 2010 in both rural and urban areas along the water-course (R² = 0.99; RMSE = 1.41 m and CV (RMSE) = 0.04). In urban areas distant from the river, however, flood levels were over-estimated, indicating a need to use more detailed Digital Elevation Models. Flood events with return period greater than 50 years have the potential to cause great damage (floods exceeding 0.46 km2 in the urban area). The study showed that the use of coupled models was a viable approach for mapping areas liable to flooding, when it is not possible to analyse local flow frequencies in support of a hydraulic model.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Coupling, Floods, Models
in
Revista Brasileira de Recursos Hidricos
volume
21
issue
1
pages
16 pages
publisher
Brazilian Journal of Water Resources
external identifiers
  • scopus:85018320577
  • wos:000407698100015
DOI
10.21168/rbrh.v21n1.p152-167
language
English
LU publication?
yes
id
90259408-4c3b-45ea-ae9e-a549000aa7b6
date added to LUP
2017-05-24 14:55:18
date last changed
2017-09-18 11:37:22
@article{90259408-4c3b-45ea-ae9e-a549000aa7b6,
  abstract     = {<p>Overbank flooding caused by historically high flows, such as that in the Rio Mundaú watershed (lying between the states of Alagoas and Pernambuco) in 2010, has been the cause of widespread damage. The purpose of work described in this paper was to propose a mapping of areas liable to flooding in the township of Rio Largo (Alagoas) in the Rio Mundaú watershed by means of an “off-line” coupling of the hydrological/hydraulic models (MGB-IPH/ HEC-RAS), through consideration of extreme floods with different return periods for discharge. The hydrological model had a parameterization appropriate for extreme floods, using as input rainfall data with different return periods. Calibration and validation of the hydrological model were adequate in drainage areas larger than 1500 km2, but were less acceptable in headwater drainage areas where different geology and soil cover gave rise to surface runoff. The hydraulic model showed good agreement with point observations of flood levels in 2010 in both rural and urban areas along the water-course (R² = 0.99; RMSE = 1.41 m and CV (RMSE) = 0.04). In urban areas distant from the river, however, flood levels were over-estimated, indicating a need to use more detailed Digital Elevation Models. Flood events with return period greater than 50 years have the potential to cause great damage (floods exceeding 0.46 km2 in the urban area). The study showed that the use of coupled models was a viable approach for mapping areas liable to flooding, when it is not possible to analyse local flow frequencies in support of a hydraulic model.</p>},
  author       = {Monte, Benício Emanoel Omena and Costa, Denis Duda and Chaves, Mahelvson Bazilio and de Oliveira Magalhães, Louis and Uvo, Cintia B.},
  keyword      = {Coupling,Floods,Models},
  language     = {eng},
  number       = {1},
  pages        = {152--167},
  publisher    = {Brazilian Journal of Water Resources},
  series       = {Revista Brasileira de Recursos Hidricos},
  title        = {Hydrological and hydraulic modelling applied to the mapping of flood-prone areas},
  url          = {http://dx.doi.org/10.21168/rbrh.v21n1.p152-167},
  volume       = {21},
  year         = {2016},
}