Hidrološka analiza kraških izvirov v Sloveniji : magistrsko delo

Jelen, Maja (author), Bezak, Nejc (mentor), Mikoš, Matjaž (co-mentor)

Kras je mogoče najti povsod po Sloveniji, z izjemo Severovzhodnega dela države. Kraški vodonosniki so pomemben vir pitne vode, hkrati pa zaradi sposobnosti hitrega pretakanja vode in morebitnih onesnaževal, predstavljajo ranljiv sistem. Hidrološka analiza kraških izvirov obsega analizo trendov najmanjših, srednjih in največjih letnih pretokov v 14 kraških izvirih, razporejenih po celotni Sloveniji. Naloga podaja opis nastanka krasa in kraškega vodonosnika, opiše mehanizem polnjenja kraškega vodonosnika in pretakanja vode v njem, opiše vrste kraških izvirov in podaja pregled večjih kraških izvirov v Sloveniji. V nalogi je bila statistična analiza trendov narejena z uporabo Mann-Kendallovega testa in z metodo linearne regresije. S Pettittovim testom je bilo poiskano leto, v katerem pride do nenadne spremembe trenda, na podlagi tega leta pa je bila časovna vrsta razdeljena na dve podvrsti. Linearni trendi srednjih letnih pretokov so bili analizirani tudi za podvrsti. Obravnavane so bile značilnosti hidroloških podatkov. V analizo trendov hidroloških in meteoroloških spremenljivk, so bile zajete popolne časovne vrste podatkov, ki so bile predhodno pregledane, manjkajoče vrednosti pa po potrebi dopolnjene. Obravnavano je bilo spreminjanje temperature vode v 7 kraških izvirih in preverili smo odvisnost med temperaturo vode v kraških izvirih in temperaturo zraka. Prav tako so bili za izbrane meteorološke postaje ugotovljeni trendi temperature zraka in trendi vsote letnih padavin. V nalogi nas je zanimal tudi vpliv padavin na trende srednjih letnih pretokov. Rezultati so pokazali statistično značilno upadanje srednjih letnih pretokov v 12 izmed 14 analiziranih kraških izvirih, prav tako se statistično značilni trend upadanja najmanjših letnih pretokov pokaže v 11 od 14 kraških izvirih. Temperatura vode narašča v 5 od 7 izbranih kraških izvirih, od tega v 3 kraških izvirih tudi statistično značilno. Kot leto preloma je bilo največkrat določeno leto 1982.

• Language: Slovenian
• Keywords: Kraški izviri, trendi, pretoki, Mann-Kendallov test, Pettittov test, linearna regresija, temperatura vode
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Year: 2019
• PID: 20.500.12556/RUL-110377
• COBISS.SI-ID: 8891745
• Publication date in RUL: 14.09.2019

Secondary language

• Language: English
• Title: Hydrological analysis of karst springs in Slovenia : master thesis

Abstract

Karst can be found all over the Slovenia with the exception of its northeastern part. Karst aquifers are an important source of drinking water, but due to their characteristics can also be very vulnerable. The Master thesis includes an analysis of annual low, mean and maximum daily discharge or water level trends for 14 karst springs in Slovenia. Time series of 53 years was used in the analysis, with the exception of three karst springs with shorter sets of hydrological data measurements. The process of karst formation, characteristics of karst aquifer and the mechanism of water flow and recharging in the karst aquifer are presented. Additionally, different types of karst springs are described and a general overview of karst springs in Slovenia is given. Statistical analysis of the discharge trends was performed by using the Mann-Kendall test and method of linear regression. Trend change point in mean annual discharge was detected by using the Pettitt test. Detected change point divided the mean annual discharge time series in two separate time series and trend for subseries was analysed. All time series used in the thesis were previously reviewed and missing values were filled in, so only complete times series of hydrological and meteorological data were used. Trends and changes in water temperature were analysed for 7 karst springs. Trends in annual amount of precipitation and trends in air temperature for selected meteorological stations were also identified. Correlation between annual amounts of precipitation and discharges were calculated as well. The results of hydrological analysis show statistically significant decrease in mean annual discharge in 12 of the 14 karst springs that were included in the analysis. Additionally a decreasing trend in annual low discharge values for 11 out of 14 karst springs was detected. Water temperature is increasing in 5 of 7 selected karst springs - for 3 of them the increasing trend is also statistically significant. Year 1982 was most often detected as the change point in the investigated samples.

• Keywords: Karst springs, trends, discharge, Mann- Kendall test, Pettitt test, linear regression, water temperature