Podnebne spremembe vplivajo na pogostejše poplave morja

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https://doi.org/10.59132/geo/2019/3/30-34

Povzetek

Podnebne spremembe z rastjo temperatur povzročajo dviganje gladine morij, ki se v zadnjih desetletjih opazno povečuje. Razlog za to je v večji prostornini toplejše morske vode in v povečanem dotoku sladke vode s celin zaradi krčenja ledenih pokrovov na polih ter gorskih ledenikov. Tudi podatki mareografske postaje v Kopru kažejo trend dviganja morske gladine, ki ob višjih plimah že zdaj pogosto poplavi niže ležeče dele slovenske obale. Zanimalo nas je, kako se bo povečala poplavljenost ob predvideni srednji višini morja, višji za 50 in za 100 cm. Upoštevali smo različno visoke plime in ugotovili, da bodo pri dvigu morske gladine za 50 cm že nekoliko višje plime povzročale poplave, ob plimah, ki zdaj povzročajo poplave, bo na najniže ležečih delih obale 80 cm vode in poplavljenih bo okoli 700 ha zemljišč. Pogoste vsakoletne poplave bodo primerljive s sedanjimi izjemnimi. Pri dvigu morske gladine za 100 cm pa bi bili nižji deli obale poplavljeni že ob srednji plimi in suhi le ob oseki. Ob višji plimi bi se poplavne površine razširile na več kot 1200 ha in bi močno ogrozile urbanizirana območja, med drugimi tudi staro mestno jedro Pirana.

Abstract

Climate Change Increasing Frequency of Sea Flooding

Climate change with temperature growth causes increasing of the sea level which has been noticeably increasing in recent decades. The reason is the higher volume of the warmer seawater and the increased inflow of freshwater from the continents due to the shrinkage of the polar ice caps and mountain glaciers. Data from the sea level gauging station in Koper also show increasing trend of the sea level which often floods the lower lying parts of the Slovenian coast at high tides. We were interested in how the flooding will increase at the predicted rising of the mean sea height of 50 or 100 cm. We took into account high tides of different heights and found out that at the sea level rise of 50 cm slightly higher high tides will already cause sea flooding. At high tides similar to those already causing sea flooding today, approximately 80 cm of water will cover lower laying parts of coastal region and around 700 ha of land will be flooded. Frequent annual floods will be comparable to the current exceptional ones. At the sea level rise by 100 cm, the lower laying parts of the coast would be flooded already at mean high tides and stay dry only at low tides. At higher high tides flooding area would spread over 1200 ha and would greatly undermine urban areas, including the old city centre of Piran.