Rainfall erosivity analysis in Slovenia

Za Slovenijo so značilni padavinski dogodki visoke intenzitete in krajšega trajanja, kar jo uvršča med območja z višjimi vrednostmi erozivnosti padavin v Evropi. V magistrski nalogi je predstavljeno stanje na področju analiz erozivnosti padavin in z njo povzročene erozije talopisane so vrste erozije, dejavniki, ter podrobno obravnavan eden izmed njih – dejavnik erozivnosti padavin. S pomočjo izbranih programskih orodij (R, RIST, Orange in SAGA) so bile za izbranih deset pluviografskih postaj po Sloveniji najprej izračunane vrednosti faktorja erozivnosti padavin in površinskega odtoka (R-faktorja) – in sicer po posameznih letih, mesecih, ter s pomočjo izbranih enačb po različnih avtorjih (Brown in Foster, van Dijk, Petan) tudi izvedena primerjava in analiza rezultatov. Eden od ciljev naloge je bila določitev občutljivosti vhodnih parametrov modela izračuna erozivnosti padavin in njihov vpliv na končno vrednost faktorja erozivnosti R, za kar je bila izvedena analiza občutljivosti s pomočjo metod normaliziranega kazalnika občutljivosti in standardnega regresijskega koeficienta. S pomočjo izračunanih letnih vrednosti R faktorja je bila izvedena analiza trenda z metodo Mann-Kendall, analizirana podobnost vzorcev s testom Mann-Whitney ter ovrednoteni rezultati glede na sorodne študije v preteklosti. Analizirana je bila tudi sezonskost faktorja R za izbrane pluviografske postaje v Sloveniji, ter s pomočjo analize sezonskih grafov izvedena klasifikacija vseh obravnavanih postaj glede na njihove sezonske značilnosti. Za izbrano območje porečja Save do vodomerne postaje Kranjska gora (v okolici pluviografske postaje Rateče) je bil predstavljen izračun erozije tal s pomočjo metode RUSLE, ter analizirani vplivi spreminjanja dejavnikov (R, K, LS, C, P) na končno oceno izgube tal zaradi erozije.Slovenia is characterised by rainfall events of high intensity and short duration, which puts it among areas with high rainfall erosivity values in Europe. This Master\u27s thesis focuses on the current state in rainfall erosivity and soil erosion connected to it. Types of erosion, the physical forms and factors of soil erosion are presented, with in-depth analysis of one of its main characteristics – the rainfall erosivity factor R. Using various tools (R, RIST, Orange and SAGA), calculations and analyses were performed for selected pluviographic stations across Slovenia. R-factor was determined by year, month and in accordance with various equations of different authors (Brown and Foster, van Dijk, Petan), after which comparisons were drawn and results analysed. Determining the sensitivity of input model parameters and their effect on model output R-factor values was one of the goals of the study. This was achieved using sensitivity analysis tools – Normalized Sensitivity Index and Standardized Regression Coefficient. Using annual values of R-factor, a trend analysis was performed, using Mann-Kendall test, after which different samples were compared according to the Mann-Whitney test. The results were evaluated in comparison to similar studies and literature. The seasonality of R-factor for the selected pluviographic stations was analysed, along with the classification according to seasonality traits. For a selected area, the calculation of soil erosion was presented, according to the RUSLE method. The change in input parameters of RUSLE equation (R, K, LS, C, P) were analysed and their impact on soil erosion values evaluated