Naslov
Modelling of extreme dry spells in Croatia – the threshold selection

Autori
Cindrić, Ksenija ; Pasarić, Zoran ; Gajić Čapka, Marjana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
11th International Conference on Meteorology, Climatology and Atmospheric Physics

Mjesto i datum
Atena, Grčka, 29.05.2012. - 01.06.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
dry spells; Croatia; threshold; Generalised Pareto distribution

Sažetak
In order to estimate the occurrence of long dry spells different return periods obtained from certain extreme value distribution are usually employed. When dealing with climatological extremes the block maxima approach is traditionally used. However, in recent years the peaks over threshold (POT) approach comes into the focus because of its ability to better utilize the available data. The main problem in this approach is how to choose the threshold in a systematic way. In this study we put emphasis on this issue while analysing dry spell series in Croatia. Daily precipitation data from the 1961-2010 period at 25 meteorological stations are used to construct dry spell series based on the daily precipitation amount of less than 1 mm. Simulated dry spell series based on Generalized Pareto (GP) distribution are also used. Several methods for threshold selection are examined employing a whole range of percentile values. It is found that unique threshold can not be recommended for dry spells. Instead, it seems the best option is to utilise GP distributions over a range of percentiles. The mean values of GP parameters thus obtained are subsequently used for estimation of return periods.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA