Vízügyi Közlemények, 2000 (82. évfolyam)

2. füzet - Koris K.-Winter J.: Az 1999. évi nyári rendkívüli árvizek a Mátra és a Bükk déli vízgyűjtőin

Az 1999. évi nyári rendkívüli ái-vizek a Máira és a Bükk déli vízgyűjtőin 217 Kontur I.-Kőris K.-Winter J.: Hidrológiai számítások. Akadémia Kiadó Budapest, 1993. Winter I.-Koris K.: Az Ágói patakon 1989. július 10-14-én levonult árhullám hidrológiai vizsgálata. Hidrológiai Közlöny, Budapest, 1991/4. 213-218. old. * * * Extraordinary summer floods of 1999 in the southern catchments of the mountains Mátra and Bükk by Dr. Kálmán KORIS and Dr. János WINTER Ph.D. civil engineers In the summer of 1999 extreme floods were generated by excessive rainstorms in the creeks Laskó, Eger, Hór and Kácsi-Sályi (Figure /.). Extreme floods are usually generated when the soil moisture and the fullness of the channels are high due to antecedent precipitation events. These characteristics are well reflected by the antecedent precipitaiton index (Table /.). The different precipitation events of different stations can be correctly compared only when their probability of occurrence, corresponding to an appropriately selected base period, is calculated. Table II. shows the characteristics of rainfalls of higher than P=0.1 % probability (1,000 year frquency of occurence). The areal distributions of the rainfalls of the 10

t

h of July 1999, 9-10 July and 7-14 July of 1999 are shown in Figure s 2., 3., and 4. respectively. The figures indicate that the rainfall was not point-like but covered relatively large areas, spanning over several gauging stations. Maximum flood flows were calculated by hydrological and hydraulic methods and the results were compared. The data needed for the calculations are included in tables III., IV., V, VI., and VII. On the basis of the hydrological investigations it was found, that the one-day rainfall onto the catchment of the creek Laskó exceeded 80 mm on the 10

l

h of July and also on the 16

t

h of August, which corresponds to the 1000 year return period (0.1 % probability). The flood flows of the Creek Eger were determined on the basis of observation data, using the flood-flow profile (Figure 5. ). These flows were: Q

m

m = 40 m

3 s ', and Qi%= 62 m

3 s 1. The flood discharge of the creek Hór were defined for the inflow station of the reservoir of the Hór-valley as shown in Figure 6. and the water levels of the reservoir are shown in Figure 7. The July 1999 flood of the Creek Kácsi-Sályi were extremely high, 105 m

3 s which corrcpsonds to T=200 years return period. The flood hydrograph of the Mezönyárád station of the Creek Kácsi-Sályi is shown in Figure 8. Summarising it can be stated, that the floods of July-August, 1999, of the southern catchments of the mountains Mátra and Bükk were of much lower probability than p = 0.5 % * * * Die außergewöhnlichen Sommerhochwässer von 1999 in den südlichen Einzugsgebieten des Mátra- und Bükk-Gebirges von Dr.-Ing. Kálmán KORIS und Dr.-lng. János WINTER, PhD. An den Gewäsern Laskó-. Eger-, Hór, und Kácsi-Sályi-Bach (Bild 1) haben die während des Sommers von 1999 gefallenen außerordentlichen Niederschläge außerordentliche Hochwasserwellen ausgelöst. Außerordentliche Hochwasserwellen werden gewöhnlich von Starkrc-