Flood hydrograph analysis on GS Zagreb

Analiza hidrograma velikih voda se vrlo često koristi u hidrološkoj praksi i ima veliku važnost, jer služi za brojne studije vezane za vjerojatnost plavljenja područja, projektiranje hidrotehničkih građevina te procjene utjecaja na prometnu infrastrukturu, poljoprivredna područja i sl. Provedena je analiza hidrograma velikih voda na rijeci Savi na vodomjernoj stanici Zagreb, na osnovu 60-godišnjeg niza (1960.-2019.godine) podataka o dnevnim protocima. U uvodu su prikazani osnovni pojmovi vezani za velike vode te primjeri poplava uzrokovanih samom pojavom velikih voda u vodotocima. Zatim je dano teoretsko pojašnjenje metoda (Metoda godišnjih ekstrema i POT metoda) za izdvajanje vodnih valova i metoda za statistiku obradu rezultata. Nakon toga prikazan je postupak provedbe i rezultati same analize, gdje su prikazani dobiveni vršni protoci za svaku godinu, volumeni izdvojenih vodnih valova i njihovo trajanje, te osnovni statistiki pokazatelji vezani uz te podatke. Nizovi za analizu su formirani pomoću Metode godišnjih ekstrema. Također, provedena je statistika obrada dobivenih vršnih protoka, u vidu provedbe Anderson-Darlingovog testa prikladnosti teorijske funkcije raspodjele i izbora najbolje teorijske funkcije raspodjele.The flood hydrography analysis is of great importance in hydrology, as it is used for numerous studies related to the probability of flooding, the design of hydro-engineering structures, and the impact assessments on transport infrastructure, agricultural areas, etc. An analysis of flood hydrography on the River Sava at the Zagreb gauging station is made, based on a 60-year series (1960-2019) of data on daily flows. In the introduction, the basic concepts related to flood waves and examples of floods caused by the occurrence of flood waves in watercourses are presented. Then, a theoretical explanation of the methods (Annual Maxima Method and POT method) for flood wave extraction and methods for statistical analysis of results is given. After that, the implementation procedure and the results of the analysis are presented, where the obtained peak flow for each year, the volumes of separated flood waves and their duration, and the basic statistical parameters related to these data are presented. The annual maxima method was used to form time series. At the end, statistical analysis of the obtained peak flows was performed, in the form of a Anderson-Darling test for goodness of fit of the theoretical distribution function and selection of the best theoretical distribution function