Empirical statistical characterization and regionalization of amplitude–duration–frequency curves for extreme peak flows in the Lake Victoria Basin, East Africa
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Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Hydrological Sciences Journal
Abstract
This paper focuses on a regionalization attempt to partly solve data limitation problems in statistical
analysis of high flows to derive discharge–duration–frequency (QDF) relationships. The analysis is based on 24
selected catchments in the Lake Victoria Basin (LVB) in East Africa. Characteristics of the theoretical QDF
relationships were parameterized to capture their slopes of extreme value distributions (evd), tail behaviour and
scaling measures. To enable QDF estimates to be obtained for ungauged catchments, interdependence relationships
between the QDF parameters were identified, and regional regression models were developed to explain the
regional difference in these parameters from physiographic characteristics. In validation of the regression models,
from the lowest (5 years) to the highest (25 years) return periods considered, the percentage bias in the QDF
estimates ranged from –2% for the 5-year return period to 27% for 25-year return period.
Description
Keywords
Extreme value analysis, Flow extremes, Floods, QDF, Regionalization
Citation
Onyutha, C., & Willems, P. (2015). Empirical statistical characterization and regionalization of amplitude–duration–frequency curves for extreme peak flows in the Lake Victoria Basin, East Africa. Hydrological Sciences Journal, 60(6), 997-1012. https://doi.org/10.1080/02626667.2014.898846