6 research outputs found
Novel indices for the comparison of precipitation extremes and floods: an example from the Czech territory
This paper presents three indices for evaluation of hydrometeorological
extremes, considering them as areal precipitation events and trans-basin
floods. In contrast to common precipitation indices, the weather extremity
index (WEI) reflects not only the highest precipitation amounts at individual
gauges but also the rarity of the amounts, the size of the affected area, and
the duration of the event. Furthermore, the aspect of precipitation
seasonality was considered when defining the weather abnormality index (WAI),
which enables the detection of precipitation extremes throughout the year.
The precipitation indices are complemented with the flood extremity index
(FEI) employing peak discharge data. A unified design of the three indices,
based on return periods of station data, enables one to compare easily
inter-annual and seasonal distributions of precipitation extremes and large
floods.
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The indices were employed in evaluation of 50 hydrometeorological extremes of
each type (extreme precipitation events, seasonally abnormal precipitation
events, and large floods) during the period 1961–2010 in the Czech Republic.
A preliminary study of discrepancies among historic values of the indices
indicated that variations in the frequency and/or magnitude of floods can
generally be due not only to variations in the magnitude of precipitation
events but also to variations in their seasonal distribution and other
factors, primarily the antecedent saturation