 |
| Titel |
Climatic and basin factors affecting the flood frequency curve: PART I – A simple sensitivity analysis based on the continuous simulation approach |
| VerfasserIn |
A. M. Hashemi, M. Franchini, P. E. O'Connell |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 4, no. 3 ; Nr. 4, no. 3, S.463-482 |
| Datensatznummer |
250001753
|
| Publikation (Nr.) |
 copernicus.org/hess-4-463-2000.pdf |
|
|
|
|
|
| Zusammenfassung |
Regionalized and at-site flood frequency curves exhibit considerable
variability in their
shapes, but the factors controlling the variability (other than sampling
effects) are not well understood. An application of the Monte Carlo
simulation-based derived distribution approach is presented in this two-part
paper to explore the influence of climate, described by simulated rainfall and
evapotranspiration time series, and basin factors on the flood frequency curve (ffc).
The sensitivity analysis conducted in the paper should not be interpreted as
reflecting possible climate changes, but the results can provide an indication
of the changes to which the flood frequency curve might be sensitive.
A single site Neyman Scott point process model of rainfall, with convective
and stratiform cells (Cowpertwait,
1994; 1995), has been employed to generate synthetic rainfall inputs to a
rainfall runoff model. The time series of the potential evapotranspiration (ETp)
demand has been represented through an AR(n) model with seasonal component,
while a simplified version of the ARNO rainfall-runoff model (Todini, 1996) has
been employed to simulate the continuous discharge time series. All these models
have been parameterised in a realistic manner using observed data and results
from previous applications, to obtain ‘reference’ parameter sets for a
synthetic case study. Subsequently, perturbations to the model parameters have
been made one-at-a-time and the sensitivities of the generated annual
maximum rainfall and flood frequency curves (unstandardised, and standardised by
the mean) have been assessed.
Overall, the sensitivity analysis described in this paper suggests that the soil moisture
regime, and, in particular, the probability distribution of soil moisture
content at the storm arrival time, can be considered as a unifying link
between the perturbations to the several parameters and their effects on the
standardised and unstandardised ffcs, thus revealing the physical mechanism
through which their influence is exercised. However, perturbations to the
parameters of the linear routing component affect only the unstandardised ffc.
In Franchini et al. (2000), the sensitivity analysis of the
model parameters has been assessed
through an analysis of variance (ANOVA) of the results obtained from a formal
experimental design, where all the parameters are allowed to vary simultaneously,
thus providing deeper insight into the interactions between the different
factors. This approach allows a wider range of climatic and basin conditions to
be analysed and reinforces the results presented in this paper, which provide
valuable new insight into the climatic and basin factors controlling the ffc.
Keywords: stochastic rainfall model; rainfall runoff model; simulation; derived distribution; flood
frequency; sensitivity analysis |
| |
|
| Teil von |
|
|
|
|
|
|
|
|