On the possibilities of watershed parameterization for extreme flow estimation in ungauged basins
The estimation of design discharges and water levels of extreme floods is one of the most important parts of the design process for a large number of engineering projects and studies. Design flood estimates require a consideration of the hydrological, meteorological and physiographical situation...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-06-01
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| Series: | Proceedings of the International Association of Hydrological Sciences |
| Online Access: | https://www.proc-iahs.net/370/171/2015/piahs-370-171-2015.pdf |
| Summary: | The estimation of design discharges and water levels of extreme floods is
one of the most important parts of the design process for a large number of
engineering projects and studies. Design flood estimates require a
consideration of the hydrological, meteorological and physiographical
situation, the legal requirements, and the available estimation techniques
and methods. In the last decades changes in floods have been observed (Hall
et al., 2014) which makes design flood estimation particularly challenging.
Methods of design flood estimation can be applied either locally or
regionally. A significant problem may arise in small catchments that are
poorly gauged or when no recorded data exist. To obtain the design values in
such cases, many countries have adopted procedures that fit the local
conditions and requirements. One of these methods is the Soil Conservation
Service – Curve number (SCS-CN) method which is often used in design flood
estimation for ungauged sites, including those in Slovakia. Since the method
was derived on the basis of the specific characteristics of selected river
basins in the United States, it may lead to significant uncertainties in
other countries with different hydrological conditions. The aim of this
study was to test the SCN-CN method and derive regional runoff curve numbers
based on rainfall and discharge measurements for selected region in
Slovakia. The results show that the classical CN method gives too high
estimates of event runoff depths and is not valid in the study area. To
avoid the overestimation of runoff caused by extreme rainfall events, the
use of the empirically derived regional runoff curves was tested and finally
proposed for practical application in engineering hydrology. |
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| ISSN: | 2199-8981 2199-899X |