I. del PREGLED HIDROLO[KIH RAZMER V LETU 2005 Part I REVIEW OF HYDROLOGICAL CONDITIONS IN THE YEAR 2005 HIDROLO[KI LETOPIS SLOVENIJE 2005 THE 2005 HYDROLOGICAL YEARBOOK OF SLOVENIA A. POVR[INSKE VODE A. SURFACE WATERS Vodostaji in pretoki rek River stages and discharges Igor Strojan Igor Strojan Leta 2005 so se ~asovna razporeditev vodnatosti ter veli- In 2005, the temporal distribution of stages and the size kosti in lokacije najve~jih pretokov dokaj razlikovale and location of the highest discharges differed a good od obi~ajnih. Vodnatost je bila manj{a v prvi polovici deal from the usual.The river stages were lower in the in ve~ja v drugi polovici leta.Velika vodnatost v polet- first half and higher in the second half of the year.The nih mesecih je spominjala na mo`ne neugodne scena- great stages in the summer months hinted at the pos- rije posledic podnebnih sprememb. Reke so najmo~neje sible unfavourable scenarios of the consequences of cli- poplavljale avgusta. Predvsem veliki pretoki Mure in mate change. Rivers caused the most severe floods in manj{ih hudourni{kih rek v vzhodnem delu dr`ave, ki August. It was the high discharges of the Mura River so presegali tudi 50 letne povratne dobe, so povzro~i- and the smaller torrential rivers in the eastern part of li veliko {kode. Na Muri v Gornji Radgoni je bil izmer- the country especially that even exceeded the 50-year jen do tedaj najve~ji pretok 1380 m3/s. Sicer je bila return periods and caused a lot of damage. The high- vodnatost rek v letu 2005 v celoti nekaj ve~ kot deset est discharge to date (1380 m3/s) was measured on odstotkov manj{a od dolgoletnega povpre~ja v obdob- the Mura River at Gornja Radgona. Otherwise, the ju 1971–2000. Brez upo{tevanja avgustovske velike vod- river stages in 2005 were on the whole somewhat more natosti rek bi bila povpre~na letna vodnatost rek than 10% lower than the multi-annual mean of the v letu 2005 veliko manj{a.Ve~ji del leta je bila mese~- 1971–2000 reference period. If the high river stages in na vodnatost rek manj{a kot v primerjalnem obdobju. August were not taken into account, the average Ker je bila v obi~ajno poletno su{nem obdobju vodna- annual river stages in 2005 would be much lower. For tost rek pove~ana, izrazitega su{nega obdobja ni bilo. a major part of the year, the monthly river stages were Povpre~ni letni pretoki rek so bili najmanj{i v zahod- lower than in the reference period. However, because nem in najve~ji v vzhodnem delu dr`ave. Najmanj vode the river stages in the usually dry summer period G. Radgona Videm Polana Radovljica [entjakob 3 3 7 2 2 6 2 2 5 4 1 1 3 1 1 2 1 0 0 0 0 0 Hrastnik Radenci Cerkvenikov mlin Suha Moste 3 3 3 3 3 2 2 2 2 2 1 1 1 1 1 0 0 0 0 0 V. [irje Podbo~je Kobarid Solkan Miren 4 4 1 2 3 3 3 2 2 2 1 1 1 1 0 0 0 0 0 Slika 5: Razmerja med srednjimi mese~nimi pretoki leta 2005 in obdobja 1971–2000. Vrednost razmerja 1 pomeni enak pretok leta 2005 kot v povpre~ju dolgoletnega obdobja. Figure 5: Ratios between mean monthly discharges in 2005 and in the 1971–2000 reference period. The ratio value of 1 means that the discharge in 2005 was the same as the multi-annual mean. 24 ARSO HIDROLO[KI LETOPIS SLOVENIJE 2005 THE 2005 HYDROLOGICAL YEARBOOK OF SLOVENIA were increased, there was no pronounced drought 3 period. The average annual river discharges were lowest in the western and highest in the eastern parts of the coun- atios 2,3 try.The least water flowed in the So~a River (38% less than usual) and the most in the Mura River (15% more 2 than usual). The annual discharges of the Sava River were lower in the upstream part (25% lower than usual) than in the downstream part (10% lower than usual). The river stages of the Ljubljanica River were 15% lower, 1,2 1,1 1,0 1,1 while those of the Krka River were 12% higher than 1 0,9 0,8 in the reference period. 0,7 0,6 The majority of months in 2005 were hydrologi- 0,5 cally dry.The mean river discharges of the multi-annu- Razmerja pretokov / Discharge r 0,4 0,4 al period were exceeded in the summer months, especially in August, when the monthly discharges were exceed- 0 123 4 5 67891011 12 ed 2.3 times on average. In September and December, the monthly discharges were exceeded by around 15%. Slika 6: Razmerja med srednjimi mese~nimi pretoki They were similar to the multi-annual mean in April, v letu 2005 in obdobnimi srednjimi mese~nimi pretoki. Raz- while in the remaining months they were lower than the merja so izra~unana kot povpre~ja razmerij na izbranih multi-annual mean. Discharges were lowest in February postajah. and June, when they were as much as 62% lower than Figure 6: The ratios between the mean monthly discharges the multi-annual mean. In November, the river stages in 2005 and the multi-annual mean monthly discharges. The were lower than usual by a half. ratios are calculated as average values of the ratios at selected The majority of the highest discharges in the larg- stations. er rivers were not higher than in the multi-annual ref- erence period. The high-water peaks were largest on je tako preteklo po So~i (38 odstotkov manj kot navad- the Mura River at Gornja Radgona (a 1.8-times higher no) in najve~ po Muri (15 odstotkov ve~ kot navadno). peak than the multi-annual mean), the Ledava River Letni pretoki Save so bili v zgornjem toku manj{i at Polana (a 1.9-times larger peak than the multi-annu- (25 odstotkov manj{i kot navadno) kot v spodnjem al mean), the Kolpa River at Radenci (a 1.4-times larger (10 odstotkov manj{i kot navadno). Vodnatost Ljub- peak than the multi-annual mean) and the Krka River at ljanice je bila 15 odstotkov manj{a, vodnatost Krke Podbo~je (a 1.1-times larger peak than the multi-annu- 12 odstotkov ve~ja kot v primerjalnem obdobju. al mean). The high-water peaks were smallest on the 700 600 3 500 400 300 200 Pretok / Discharge (m /s) 100 0 1. jan 1. feb 1. mar 1. apr 1. maj 1. jun 1. jul 1. avg 1. sep 1. okt 1. nov 1. dec Povpre~ni dnevni pretoki 2005 / The 2005 mean daily discharges Povpre~ni mese~ni pretoki (1971–2000) / Mean monthly discharges (1971–2000) Slika 7: Srednji dnevni pretoki v letu 2005 in srednji mese~ni pretoki v dolgoletnem obdobju 1961–2000 na reki Savi v Hrastniku. Figure 7: The mean daily discharges in 2005 and the mean monthly discharges in the 1961–2000 reference period on the Sava River at Hrastnik. ARSO 25 H IDROLO[KI LETOPIS SLOVENIJE , 2005 T atios 5 , sQnp/sQnp 4 3 , nQnp/sQnpvQnp/sQnp)2 1 HE Razmerja pretokov / Discharge r 2005 H (Qnp/sQnp YDROLOGICAL 0 G. Radgona YEARBOOK OF Videm Razmerja malihPolana pretokov 2005 / Low discharge ratios in 2005 SLOVENIA Razmerja malih karakteristi~nihRadovljica pretokov 1971–2000 / Characteristical low discharge ratios 1971–2000 atios 5 , [entjakob Hrastnik 4 , sQs/sQs Suha Moste 3 V. [irje , nQs/sQsvQs/sQs) 2 Podbo~je Radenci (Qs/sQs Razmerja pretokov / Discharge1 r Cerkvenikov mlin Kobarid 0 Solkan G. Radgona Miren Videm Razmerja srednjihPolana pretokov leta 2005 / Medium discharge ratios in 2005 Razmerja srednjih karakteristi~nihRadovljica pretokov 1971–2000 / Characteristical medium discharge ratios 1971–2000 atios 5 [entjakob Hrastnik sQvk/sQvk, 4 Suha Moste 3 V. [irje nQvk/sQvk, vQvk/aQvk)2 Podbo~je Radenci Razmerja pretokov / Discharge1 r Cerkvenikov mlin (Qvk/sQvk, Kobarid 0 Solkan G. Radgona Miren Videm Slika 8: Razmerja velikihPolana pretokov leta 2005 / High discharge ratios 2005 Vrednosti so podane relativno glede na srednje vrednosti malih, srednjih in velikih obdobnih pretokov. Razmerja malih,Razmerja srednjih invelikih velikih karakteristi~nih Radovljicapretokov v letupretokov 2005 1971–2000 ter razmerja / Characteristical karakteristi~nih high pretokov discharge obdobja ratios 1971–2000 1971–2000. Figure 8: reference period. The values are given in relation to the mean[entjakob values of the all-time low, mean and high discharges. The ratios of low, mean and high discharges in 2005 andHrastnik the ratios of the characteristic discharges in the 1971–2000 26 Suha Moste V. [irje Podbo~je Radenci Cerkvenikov mlin Kobarid Solkan Miren ARSO HIDROLO[KI LETOPIS SLOVENIJE 2005 THE 2005 HYDROLOGICAL YEARBOOK OF SLOVENIA Preglednica 3: Zna~ilni pretoki v letu 2005 in obdobju 1971–2000. Table 3: Characteristic discharges in 2005 and in the 1971–2000 reference period. Reka / Postaja/ Qnp nQnp sQnp vQnp River Station Avgust / August 2005 Avgust / August 1961–1990 m3/s dan / day m3/s m3/s m3/s Mura G. Radgona 136 15 67,3 115 223 Drava# Borl + Formin 227 11 103 250 393 Dravinja Videm 3,0 1 0,99 3,1 8,1 Savinja Veliko [irje 16,0 2 6,2 12 22,2 Sotla Rakovec 2,0 2 1 1,3 2,8 Sava Radovljica 11,0 5 8,7 16,2 33,5 Sava Medno 34,0 20 24,5 39,9 62,7 Sava Hrastnik 51,0 1 39,3 67,3 97,6 Sava ^ate` 69,0 1 63,6 102 156 Sora Suha 4,5 2 3,2 5,3 10,5 Krka Podbo~je 11,0 1 5,7 14,9 25,8 Kolpa Radenci 8,3 1 3,9 7,3 12,6 Ljubljanica Moste 11,0 2 5,7 11,4 21,1 So~a Solkan 11,0 20 19,2 28,8 53,6 Vipava Dolenje 2,6 1 0,79 2,0 4,0 Idrijca Podroteja 1,7 20 1,1 1,9 3,1 Reka Cerkvenikov mlin 0,2 0,71 2,3 Qs nQs sQs vQs m3/s m3/s m3/s m3/s Mura G.