diplomska naloga
Urša Šebenik (Author), Mojca Šraj (Mentor), Dušan Žagar (Thesis defence commission member), Tjaša Griessler Bulc (Thesis defence commission member), Dušan Žagar (Thesis defence commission member), Mitja Brilly (Co-mentor)

Abstract

Med pojave, vezane na vodni krog, spadajo tudi ekstremni vremenski pojavi, kot so suše in poplave. Kljub temu, da je suša kompleksen pojav in za seboj pušča veliko gospodarsko in okoljsko škodo, spada med manj raziskane naravne nesreče. V prvem delu diplomske naloge je zato opisan pojav suše, vzroki za njen nastanek in značilnosti, v katerih se razlikuje od drugih naravnih nesreč. Za količinsko opredelitev posameznih vrst suše so danes v uporabi številni sušni indeksi. Za analizo preteklih sušnih dogodkov in trendov sušnih razmer v Sloveniji je bil izbran standardiziran padavinski indeks (SPI). Edini vhodni podatek za njegov izračun predstavljajo padavine. Izračun zahteva določitev najprimernejše teoretične porazdelitve, ki najbolje opiše padavinski niz podatkov, zato smo v nalogi poskušali ugotoviti vpliv izbire teoretične porazdelitve na vrednosti SPI. Za izbrane meteorološke postaje smo nato z izbrano teoretično porazdelitvijo izračunali SPI na šestih časovnih skalah (ena-, dvo-, tro-, šest-, devet- in dvanajstmesečni). Za presečno obdobje 1951-2004 smo ponovno opravili izračun indeksov za vse izbrane postaje in časovne skale. Ugotovili smo, da v večini primerov meteorološke postaje Ljubljana-Bežigrad, Novo mesto in Trst kažejo podoben vzorec pojavljanja sušnih in mokrih obdobij, kar bi lahko rekli tudi za meteorološki postaji Celje in Maribor-Tabor. V zadnjem delu smo poskušali opredeliti hidrološko sušo na izbranem porečju s pomočjo standardiziranega mesečnega pretoka in SPI. Medsebojna povezanost standardiziranih pretokov in padavin je za reko Pesnico za vse časovne skale izračuna SPI pozitivna, vendar se vrednosti korelacijskega koeficienta spreminjajo mesečno in glede na trajanje časovne skale. Najvišja korelacija je izračunana med septembrskim SPI-2 in standardiziranim septembrskim pretokom.

Keywords

VKI;diplomska dela;suša;padavine;verjetnostna porazdelitev;standardiziran padavinski indeks;časovna skala;standardiziran pretok;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FGG - Faculty of Civil and Geodetic Engineering
Publisher: [U. Šebenik]
UDC: 551.577.38:005.642.5(043.2)
COBISS: 5749089 Link will open in a new window
Views: 2173
Downloads: 467
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Other data

Secondary language: English
Secondary title: Drought analysis using standardized precipitation index
Secondary abstract: Among the occurrences related to water cycle there are also extreme weather phenomena like drought and floods. Despite the fact the drought is a complex phenomena which causes a lot of economic and environmental damage, still is one of the less explored natural disasters. Therefore in the first part of this thesis we described features of drought, the reasons for its appearance and characteristics which distinguish it from other natural disasters. To quantify the various types of drought there are numerous drought indices in use. For the analysis of past drought events and trends in drought in Slovenia we selected Standardized Precipitation Index. The only input data for its calculation is based on monthly rainfall. The calculation requires determining the most appropriate theoretical distribution that best describes the precipitation data set. So we tried to find in thesis the influence of theoretical distributions on the values of SPI. With the most appropriate theoretical contribution we calculated SPI for selected meteorological stations at six different time scales (one-, two-, three-, six-, nine-and twelvemonth). For the period 1951-2004, we did again the calculation of indices for all selected stations and time scales. We found out that in most cases, the meteorological stations of Ljubljana-Bežigrad, Novo mesto and Trieste show a similar pattern of occurrence of drought and wet periods, which could be also said for the meteorological stations of Celje and Maribor-Tabor. In the last part of thesis we tried to identify the hydrological drought in the selected river basin of river Pesnica through a standardized monthly flow and SPI. The interrelation of standard flow and precipitation of Pesnica is positive for all time scales of SPI calculation. However the values of the correlation coefficient vary monthly and depends on the duration of time scale. The highest correlation is calculated between SPI-2 in September and standardized September flow.
Secondary keywords: drought;precipitation;probability distribution;standardised streamflow;
File type: application/pdf
Type (COBISS): Undergraduate thesis
Thesis comment: Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Pages: XIV, 123 str., 2 pril.
ID: 8712463