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| Titel |
Flood Frequency Analysis for Nonstationary Annual Peak Records in an Urban Drainage Basin |
| VerfasserIn |
G. Villarini, J. A. Smith, F. Serinaldi, J. Bales, P. D. Bates, W. F. Krajewski |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023991
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| Zusammenfassung |
| Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual
peak records associated with land use change and evolving urban stormwater infrastructure.
In this study, a framework for flood frequency analysis is developed based on the Generalized
Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool for modeling
time series under nonstationary conditions. GAMLSS is applied to annual maximum peak
discharge records for Little Sugar Creek, a highly urbanized watershed which drains the
urban core of Charlotte, North Carolina. It is shown that GAMLSS is able to describe the
variability in the mean and variance of the annual maximum peak discharge by modeling the
parameters of the selected parametric distribution as a smooth function of time via cubic
splines. Flood frequency analyses for Little Sugar Creek (at a drainage area of 110 km2)
show that the 100-year flood peak over the 83-year record has ranged from a minimum unit
discharge of 2.1 m3s-1km-2 to a maximum of 5.1 m3s-1km-2. An alternative
characterization can be made by examining the return interval of the peak discharge that has a
return interval of 100 years (3.2 m3s-1km-2), based on the assumption that the
83-year record is stationary. Under the GAMLSS model, the return interval of an
annual peak discharge of 3.2 m3s-1km-2 ranges from a maximum value of more
than 5000 years in 1957 to a minimum value of almost 8 years for the present time
(2007). The GAMLSS framework is also used to directly examine the links between
population trends and flood frequency, as well as trends in annual maximum rainfall.
These analyses are used to examine evolving flood frequency over future decades. |
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