Evaluation of precipitation extremes and floods and comparison between their temporal distributions

0480061 - ÚFA 2018 RIV DE eng J - Článek v odborném periodiku
Müller, Miloslav - Kašpar, Marek - Valeriánová, A. - Crhová, L. - Holtanová, E.
Evaluation of precipitation extremes and floods and comparison between their temporal distributions.
Hydrology and Earth System Sciences Discussions. Roč. 12, č. 1 (2015), s. 281-310. ISSN 1812-2108
Grant CEP: GA ČR(CZ) GAP209/11/1990
Institucionální podpora: RVO:68378289
Klíčová slova: precipitation extremes * floods
Obor OECD: Meteorology and atmospheric sciences
https://www.hydrol-earth-syst-sci.net/19/4641/2015/hessd-12-281-2015.pdf

We proposed three analogous extremity indices based on the estimated return periods at individual sites and spatial averaging of the values: we optimized both the areal extent and the duration of individual events. The weather extremity index (WEI), the weather abnormality index (WAI), and the flood extremity index (FEI) were applied to the original precipitation data, the seasonally transformed precipitation data, and the runo data to identify extreme precipitation events (EPEs), abnormal precipitation events (APEs), and extreme flood events (EFEs), respectively. We present 50 events of each type from the period of 1961-2010 in the Czech Republic and compare their inter-annual and seasonal distributions. Most of EFEs were produced by an EPE in warmer half-years, whereas fewer than half of the EFEs were produced by an APE in the remainders of the years because thawing can substantially enhance the discharge at those times. Most significant EPEs occurred in July and the first half of August, although their hydrological responses were also significantly influenced by the antecedent saturation and other factors. As a result, the accumulation of precipitation extremes during the 1977-1986 period produced less significant flooding than another accumulation after 1996. In general, the primary discrepancies between the magnitudes of EPEs and EFEs occurred in May and September, when consequent floods were usually much larger and smaller in relation to the WEI, respectively. The hydrological response to APEs was usually strong in December, whereas another accumulation of EFEs in March was usually not due to APEs. Neither precipitation nor flood extremes occurred from early April through early May. This study confirms that variations in the frequency and/or magnitude of floods can 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.
Trvalý link: http://hdl.handle.net/11104/0275979