Hrvatske vode, Vol. 30 No. 121, 2022.
Prethodno priopćenje
Potentials for implementing publicly available databases for coastal flood hazard assessment in coastal towns of the Republic of Croatia
Goran Lončar
orcid.org/0000-0002-6466-3677
; Sveučilište u Zagrebu, Građevinski fakultet, Zagreb, Hrvatska
Sažetak
The paper presents potentials of implementing publicly available databases with the aim to assess flood hazards in the coastal towns of Rovinj, Bakar, Zadar, Split, Ploče and Dubrovnik for a low, medium and high probability of high sea-level occurrences. The calculation of flooded town areas is performed in the GIS interface and based on time series of modelled sea level residuals in hourly resolution for the period of 1990-2020, as well as the digital elevation model (EU-DEM_25) from the COPERNICUS database. The sea levels for the 3 selected probabilities of occurrence on the subject locations were determined by analysing extreme values of the series with maximum values according to segments (while adapting the general distribution of extreme values) and the series of exceedances over thresholds (while adapting the general Pareto distribution). In order to estimate errors of the results obtained by using publicly available databases, the same methodological calculation sequence was carried out for a comparison purpose, but based on the commercial values of the time series of sea levels measured at mareographic stations, and the more detailed digital elevation model of the State Geodetic Administration in 5m resolution (DGU-DEM_5).
The results of the conducted investigation indicate that the average difference from the forecast maximum level is only -5.7 cm (lower sea levels when using public data), while the estimated flooded areas are on average 9% smaller when using publicly available data. Accordingly, it has been concluded that the main source of deviation from the estimated flooded area is caused by a difference in relief models and, to a significantly smaller extent, by a difference in sea level data from the COPERNICUS base and measured mareograph data.
Ključne riječi
costal floods (storm surge), COPERNICUS database, mareograph (tide gauge) measurements
Hrčak ID:
292253
URI
Datum izdavanja:
30.9.2022.
Posjeta: 467 *