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Titel |
Urbanization and climate change impacts on future urban flooding in Can Tho city, Vietnam |
VerfasserIn |
H. T. L. Huong, A. Pathirana |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 1 ; Nr. 17, no. 1 (2013-01-29), S.379-394 |
Datensatznummer |
250017697
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Publikation (Nr.) |
copernicus.org/hess-17-379-2013.pdf |
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Zusammenfassung |
Urban development increases flood risk in cities due to local changes in
hydrological and hydrometeorological conditions that increase flood hazard,
as well as to urban concentrations that increase the vulnerability. The
relationship between the increasing urban runoff and flooding due to
increased imperviousness is better perceived than that between the cyclic
impact of urban growth and the urban rainfall via microclimatic changes. The
large-scale, global impacts due to climate variability and change could
compound these risks. We present the case of a typical third world city –
Can Tho (the biggest city in Mekong River Delta, Vietnam) – faced with
multiple future challenges, namely: (i) the likely effect of climate
change-driven sea level rise, (ii) an expected increase of river runoff due
to climate change as estimated by the Vietnamese government, (iii) increased
urban runoff driven by imperviousness, and (iv) enhancement of extreme
rainfall due to urban growth-driven, microclimatic change (urban heat
islands). A set of model simulations were used to construct future scenarios,
combining these influences. Urban growth of the city was projected up to year
2100 based on historical growth patterns, using a land use simulation model
(Dinamica EGO). A dynamic limited-area atmospheric model (WRF), coupled with
a detailed land surface model with vegetation parameterization (Noah LSM),
was employed in controlled numerical experiments to estimate the anticipated
changes in extreme rainfall patterns due to urban heat island effect.
Finally, a 1-D/2-D coupled urban-drainage/flooding model (SWMM-Brezo) was
used to simulate storm-sewer surcharge and surface inundation to establish
the increase in the flood hazard resulting from the changes. The results show
that under the combined scenario of significant change in river level (due to
climate-driven sea level rise and increase of flow in the Mekong) and
"business as usual" urbanization, the flooding of Can Tho could increase
significantly. The worst case may occur if a sea level rise of 100 cm and
the flow from upstream happen together with high-development scenarios. The
relative contribution of causes of flooding are significantly different at
various locations; therefore, detailed research on adaptation are
necessary
for future investments to be effective. |
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