ACTAGEOGRAPHICA GEOGRAFSKI ZBORNIK SLOVENICA 2019 59 1 ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKI ZBORNIK 59-1 • 2019 Contents Maja KOCJANČIČ, Tomislav POPIT, Timotej VERBOVŠEK Gravitational sliding of the carbonate megablocks in the Vipava Valley, SW Slovenia 7 Małgorzata KIJOWSKA-STRUGAŁA, Anna BUCAŁA-HRABIA Flood types in a mountain catchment: the Ochotnica River, Poland 23 Irena MOCANU, Bianca MITRICĂ, Mihaela PERSU Socio-economicimpactofphotovoltaicpark:TheGiurgiucountyruralarea,Romania 37 Andrej GOSAR The size of the area affected by earthquake induced rockfalls: Comparison of the1998 Krn Mountains (NW Slovenia) earthquake (Mw 5.6) with worldwide data 51 Matej GABROVEC, Peter KUMER Land-use changes in Slovenia from the Franciscean Cadaster until today 63 Mojca FOŠKI Using the parcel shape index to determine arable land division types 83 Mateja FERK, Matej LIPAR, Andrej ŠMUC, Russell N. DRySDALE, Jian ZHAO Chronology of heterogeneous deposits in the side entrance of Postojna Cave, Slovenia 103 Special issue – Green creative environments Jani KOZINA, Saša POLJAK ISTENIČ, Blaž KOMAC Green creative environments: Contribution to sustainable urban and regional development 119 Saša POLJAK ISTENIČ Participatory urbanism: creative interventions for sustainable development 127 Jani KOZINA, Nick CLIFTON City-region or urban-rural framework: what matters more in understandingthe residential location of the creative class? 141 Matjaž URŠIČ, Kazushi TAMANO The importance of green amenities for small creative actors in Tokyo: Comparing natural and sociocultural spatial attraction characteristics 159 ISSN 1581-6613 9 771581 661010 ACTA GEOGRAPHICA SLOVENICA 2019 ISSN: 1581-6613 COBISS: 124775936 UDC/UDK: 91© 2019, ZRC SAZU, Geografski inštitut Antona Melika Internationaleditorialboard/mednarodniuredniškiodbor: DavidBole(Slovenia),MichaelBründl(Switzerland),RokCiglič(Slovenia), Matej Gabrovec (Slovenia), Matjaž Geršič (Slovenia), Peter Jordan (Austria), Drago Kladnik (Slovenia), BlažKomac (Slovenia), Andrej Kranjc (Slovenia), Dénes Lóczy (Hungary), Simon McCharty (United Kingdom), SlobodanMarković (Serbia), Janez Nared (Slovenia), Drago Perko (Slovenia), Marjan Ravbar (Slovenia), Nika Razpotnik Visković(Slovenia), Aleš Smrekar (Slovenia), Annett Steinführer (Germany), Mimi Urbanc (Slovenia), Matija Zorn (Slovenia) Editor-in-Chief/glavni urednik: Blaž Komac; blaz@zrc-sazu.si Executive editor/odgovorni urednik: Drago Perko; drago@zrc-sazu.si Chief editor for physical geography/glavni urednik za fizično geografijo: Matija Zorn; matija.zorn@zrc-sazu.siChief editor for human geography/glavna urednica za humano geografijo: Mimi Urbanc; mimi@zrc-sazu.si Chief editor for regional geography/glavni urednik za regionalno geografijo: Drago Kladnik; drago.kladnik@zrc-sazu.si Chief editor for spatial planning/glavni urednik za regionalno planiranje: Janez Nared; janez.nared@zrc-sazu.si Chiefeditorforruralgeography/glavnaurednicazageografijopodeželja:NikaRazpotnikVisković;nika.razpotnik@zrc-sazu.si Chief editor for urban geography/glavni urednik za urbano geografijo: David Bole; david.bole@zrc-sazu.si Chief editor for geographic information systems/glavni urednik za geografske informacijske sisteme: Rok Ciglič; rok.ciglic@zrc-sazu.siChief editor for environmental protection/glavni urednik za varstvo okolja: Aleš Smrekar; ales.smrekar@zrc-sazu.si Editorial assistant/uredniški pomočnik: Matjaž Geršič; matjaz.gersic@zrc-sazu.si Issued by/izdajatelj: Geografski inštitut Antona Melika ZRC SAZUPublished by/založnik: Založba ZRC Co-published by/sozaložnik: Slovenska akademija znanosti in umetnosti Address/Naslov: Geografski inštitut Antona Melika ZRC SAZU, Gosposka ulica 13, SI – 1000 Ljubljana, Slovenija The papers are available on-line/prispevki so dostopni na medmrežju: http://ags.zrc-sazu.si (ISSN: 1581–8314) Ordering/naročanje: Založba ZRC, Novi trg 2, p. p. 306, SI – 1001 Ljubljana, Slovenija; zalozba@zrc-sazu.si Annual subscription/letna naročnina: 20 € for individuals/za posameznike, 28 € for institutions/za ustanove. Single issue/cena posamezne številke: 12,50 € for individuals/za posameznike, 16 € for institutions/za ustanove. Cartography/kartografija: Geografski inštitut Antona Melika ZRC SAZU Translations/prevodi: DEKS, d. o. o. DTP/prelom: SYNCOMP, d. o. o. Printed by/tiskarna: Tiskarna Present, d. o. o. Print run/naklada: 350 copies/izvodov The journal is subsidized by the Slovenian Research Agency and is issued in the framework of the Geography of Slovenia coreresearchprogramme(P6-0101)/revijaizhajaspodporoJavneagencijezaraziskovalnodejavnostRepublikeSlovenijein nastajav okviru raziskovalnega programa Geografija Slovenije (P6-0101). The journal is indexed also in/revija je vključena tudi v: SCIE – Science Citation Index Expanded, Scopus, JCR – Journal Citation Report/Science Edition, ERIH PLUS, GEOBASE Journals, Current geographical publications, EBSCOhost,Geoscience e-Journals, Georef, FRANCIS, SJR (SCImago Journal & Country Rank), OCLC WorldCat, Google scholar,and CrossRef. Oblikovanje/Design by: Matjaž Vipotnik. Front cover photography: Stone bridge over the Rak River on the outskirts of the Rakov Škocjan polje, which is otherwiseknown for its beautiful natural bridges (photograph: Matej Lipar).Fotografija na naslovnici: Kamniti most čez reko Rak na obrobju kraškega polja Rakov Škocjan, ki je sicer bolj znano počudovitih naravnih mostovih (fotografija: Matej Lipar). FLOODTYPESINAMOUNTAIN CATCHMENT:THEOCHOTNICA RIVER,POLAND Małgorzata Kijowska-Strugała, Anna Bucała-Hrabia The Ochotnica River during the May 2014 flood. DOI: https://doi.org/10.3986/AGS.2250 UDC: 911.2:556.166(438) COBISS: 1.01 Flood types in a mountain catchment: The Ochotnica River, Poland ABSTRACT: This paper presents the results of a study on floods in the Ochotnica River catchment dur­ing forty years of hydrological observations (1972–2011). The Ochotnica River is located in the Gorce Mountains,inthePolishWesternCarpathians.ThecharacteristicsoffloodsintheOchotnicaRiverchan­nel were analyzed using limnigraphic records of water levels at the Tylmanowa gauging station and of precipitation based on data from the Polish Institute of Meteorology and the Water Management Station atOchotnicaGórna.Floodtypesweredetermined.ThepredominanttypeoffloodsintheOchotnicaRiver are normal floods with a discharge of 3.80 to 11.94m3/s in winter and 4.74 to 16.40m3/s in summer. The dominantrecentprocessisincision,atanaveragespeedof3.2cm/year.Similarresultshavebeenobserved in other mountain rivers in Europe. KEY WORDS: floods, water level, channel bed, Ochotnica River, Carpathians Vrste poplav v gorskem porečju: reka Ochotnica na Poljskem POVZETEK: V člankuavtorici predstavljata izsledke štiridesetletnihhidroloških opazovanjpoplavvpo­rečjurekeOchotnice(1972–2011).RekaOchotnicatečevpogorjuGorcevpoljskemdeluZahodnihKarpatov. Avtoricistaznačilnostipoplavvstrugirekeanaliziralinapodlagilimnigrafskihpodatkovovodnigladini, izmerjenih na merilni postaji v kraju Tilmanova, in podatkov o količini padavin, ki sta jih pridobili od Poljskega meteorološkega inštituta in vodomerne postaje v kraju Ochotnica Górna. Na podlagi tega sta določilivrstepoplav.NarekiOchotnicaprevladujejonormalnepoplavezzimskimpretokom3,80–11,9m3/sin poletnimpretokom4,74–16,40m3/s.Prevladujočiprocesvzadnjemčasujevrezovanje,insicerspovprečno hitrostjo 3,2cm/leto. Podobni rezultati so bili ugotovljeni tudi pri drugih evropskih gorskih rekah. KLJUČNE BESEDE: poplave, vodna gladina, rečna struga, reka Ochotnica, Karpati Małgorzata Kijowska-Strugała, Anna Bucała-Hrabia Polish Academy of Sciences, Institute of Geography and Spatial Organization mkijowska@zg.pan.krakow.pl, abucala@zg.pan.krakow.pl This paper was submitted for publication on July 8th, 2015. Uredništvo je prejelo prispevek 8. julija, 2015 1 Introduction The Ochotnica catchment is located intheCarpathian Mountains, the second-largest mountain range in centralEurope(Pociask-Karteczka2011).Floodsinmountaincatchmentsoccurmorequicklythaninlow­landriversbecauseofsteepslopesandnarrowvalleys(Ruiz-Villanuevaet al. 2010).Inthisarticle,aflood is understood as an event with a discharge greater than critical values, and not as water spreading over thesurfaceneartheriverchannel(Ozga-ZielińskaandBrzezinski1994).Thecourseoffloodevents,types, volumes, and durations are important factors for several practical hydrological applications, such ashydropower plant operation (Bezak, Horvat and Šraj 2015). Flood magnitude depends on precipitation intensity and duration as well as on characteristics of the catchment area, such as the length of the preceding dry period, soil moisture (water retention), vegeta­tioncover,thicknessofsnowcover,snowwatercontent,andintensityofmeltingandgroundfreezingdepth (Christenand Christen 2003;Malarz 2005; Ogden andDawdy 2003;Parajka et al. 2010;Gaal et al. 2012). Thecourseoffloodsisalsodependentonland-usechanges.Urbanization,deforestation(Borketal.1998), and agricultural intensification (van der Ploeg and Schweigert 2001) reduce the water-retention capacity ofthesoil(Mudelseeet al.2004).Thesechangescauseanincreaseinfloodrisk(YinandLi2001)andplay a key role among the natural factors shaping river channel morphology (Bronstert 2003; Barredo 2007; FrandoferandLehotský2011;Kijowska-Strugała2012;Gorczycaet al.2014).DuringthefloodinJune1957 in the Guil Valley (Queyras, southern French Alps), the entire valley bottom was affected, and the lower slopes were undermined by lateral cutting, which triggered landslides and transported enormous quan­titiesofmaterialtothevalleybottom(Arnaud-Fassetta,CossartandFort2005). Duringextremerainfalls in September 2007 in the upper Selška Sora River in Slovenia, a flash flood caused bank erosion, chan-nel-bed widening, and overbank deposition. Several debris flows and shallow landslides were triggered on the slopes, destroying the main road (Marchi et al. 2009). Changing the position of the level of river channelbottomsisoneofthemorevisiblemorphologicalprocessesinmountainareas.IntheCarpathians, incisionof1.3to3.8mcanbeobservedinriversinrecentdecades(Bucała,BudekandKozak2015;Wyżga, Zawiejska and Radecki-Pawlik 2015; Wiejaczka and Kijowska-Strugała 2015). Similar studies have been conducted in other mountain rivers of Europe; for example, between 1928 and 1989/1995 incision (locally up to 5m) was evident along the 100km length of the Drôme River (Brookes 1987; Kondolf, Piégay and Landon 2002; Liébault and Piégay 2002; Rinaldi 2003). Thestudyarea(theOchotnicacatchment)of107.6km2islocatedintheGorceMountainsintheWestern Carpathians (Figures 1, 2) characterized by deep valleys (Starkel 1972). The Ochotnica River is 22.7km long and it is a left tributary of the Dunajec River. The average slope for the entire watercourse is 36.1‰ (ranging from 56.8‰ in the upper course to 15.5‰ in the lower course). The Ochotnica River channel is carved into solid rock with numerous shelves and rock outcrops upstream, and it is cut into sediments Figure 1: Location of the study area in the Polish Carpathians (Gorce Mountains). inthemiddleandlowerparts,whereitisalsobraided(Krzemień1984).Alongtheentirecourse,theOchotnica Riverisfedbytwelvelefttributariesofandtwenty-threerighttributaries.Thetributariesplayanimportant role during flooding because they distort the natural wave of the flood, leading to delays or accelerations in the culmination of the main river below the mouth (Kijowska-Strugała 2015). RiverfloodsintheGorceMountainsfrequentlyoccurinspringandsummer.Snowmeltfloodsarethe result of thawing snow, and summer floods are the result of torrential and extreme rainfall, whereby the amountinthreetofivedayscanexceed100to250mm(Starkel1976).Suchhighrainfallleadstocatastrophic floods,asexemplifiedbythe catchmentsofKonina, Jaszcze,Jamne,andKamienicastream (Niemirowski 1974; Krzemień 1984). During the flood in July 1970, maximum daily precipitation was 154.9mm, and dischargesreached15.5m3/sand16.5m3/sinJaszczeandJamnestreams,respectively.Bankerosiondom­inated in both streams, cutting the banks from 1.2 to 7m. Mean incision of the bed reached 32cm, and the maximum was 1.2m (Niemirowski 1974). Thispaperdeterminesthetypes,duration,temporalvariability,andmagnitudeoftheOchotnicaRiver floods between 1972 and 2011. To properly identify the floods, the characteristics of the basic meteoro­logical and hydrological parameters are presented below; these include precipitation, runoff coefficient, discharge regime, and maximum discharges. To show changes in the river channel morphology caused by floods, the dynamics of the position of river channel bottoms were also analyzed, based on long-term observation series of minimum water levels. 2 Methods Data from the Institute of Meteorology and the Water Management Station were used to analyze floods. Discharges were analyzed based on limnigraphic records of water levels at the Tylmanowa gauging sta­tion closing the catchment (Figure 1) and precipitation data from the rain gauge in Ochotnica Górna. A forty-year period (1972–2011) of hydrometeorological observations was selected for detailed analysis. It is assumed thata flood is anevent in which discharges (Q) equal or exceed the discharge threshold (Qt). The selection of the criterion of flood threshold that is part of the definition of the event has a deci­siveinfluenceontheresults(e.g.Ramos,BartholmesandThielen-delPozo2007).Thedischargethreshold of the flood (Qt) was calculated using the following equation (Ozga-Zielińska and Brzezinski 1994): Qt=1(NWQ + WSQ), where NWQ is the minimal maximum discharge during the multiyear period and WSQ is the maximum mean discharge of the multiyear averages. In order to show the variability of flooding in a small mountain catchment, floods were divided into threetypes: low, normal, and high. WSQ is the threshold value oflowfloods, NWQ isthe critical valueof normalfloods,andtheaveragemaximumdischargeofthemultiyearperiod(SWQ)isusedforhighfloods. Selecting the criteria for flood threshold as part of the definition of the event has a decisive influence on the results. Floods usually depend on the season, and the seasonality approach opens the way to studying mixed floodfrequencydistributions(Sivapalanet al. 2005;Ouardaet al. 2006).Thisarticlepresentsfloodsfrom the summer (May–October) and winter (November–April) half of the hydrological year. The probability of the maximum discharges (Qmax) during floods was also calculated based on the decile method found in Dębski (1954). Astatisticalanalysiswasconductedtodeterminethemonthswiththehighestfrequencyoffloods.For each month of the hydrological year, the coefficient of variation (Cv) of average monthly discharge was calculated.Basedonthedischargecoefficient(k),theriverregimewascalculatedusingthefollowingequa­tion (Pardé 1957): k = SQM/ SQR, whereSQMistheaveragemonthlydischargeandSQRistheaverageannualdischarge.Theminimumwater levelwasusedtoidentifythedynamicsoftheOchotnicachannel(aggradationanderosionprocesses)after floods. 3 Driving force: precipitation TheaverageannualprecipitationintheUpperOchotnicafrom1972to2011was838.7mm,showingavari­abilityof629.2mm(1984)to1,109.9mm(2007).Basedontheforty-yearstudyperiod,anincreasingtrend of annual precipitation was observed in the study area, averaging 4.3mm per year (Figure 2). During the twentieth century in Europe, the mean annual precipitation has increased in northern Europe and has decreased in southern Europe (New, Hulme and Jones 1999). According to the precipitation classification by Kaczorowska (1962), nineteen years (Figure 2) were withinthenormalrange,similartotheaverageofthemultiyearperiod.Intheforty-yearperiodanalyzed, as manyas thirteenyears had above-averagerainfall (i.e., 917mm; Figure 2). On average, 64%of thepre­cipitationoccursinthesummerhalfofthehydrologicalyear(May–October).Duringtheperiodanalyzed, there were 170 days with precipitation on average; during the summer half-year, the average number of days with precipitation was ninety, and in the winter half-year seventy-five days. The maximum number ofdayswithprecipitationinthesummerhalf-yearwas120daysin1974andtheminimumsixty-twodays in 1982, whereas in the winter half-year these were 105 days (1993) and fifty days (1987), respectively. The highest monthly total precipitation was recorded in July and June, at 123 and 109mm, respectively (Figure 3). In the Carpathians and the northern part of the Alps, the annual precipitation maxima typi­ cally occur in July and August (Parajka et al. 2010). InsmallcatchmentsincentralEurope,undermoderateclimateconditions,floodsarecausedbylocal convective precipitation eventswithhigh intensity (Bryndal 2014). The highest daily rainfall occurred in the Ochotnica catchment on the following days: June 30th, 1973 (94.9mm), May 17th, 1985 (92.3mm), July 8th, 1997 (70.0mm), July 23rd, 2008 (76.3mm), and September 1st, 2010 (94.6mm). A number of studieshavedocumentedincreasesinintenseprecipitationbasedonrecords(Alpertet al.2002;KleinTank andKönnen2003). According toParajka et al. (2010), lowervariabilityinthemeandate of occurrenceof annualmaximumdailyprecipitationisobservedovertheAlpsthanovertheCarpathians.Theyalsofound thatthegreatestdailyprecipitationisconsistentlyproducedbysimilaratmosphericregimes,whereasabroad­er variety of processes are responsible for smaller events. 19721974197619781980198219841986198819901992199419961998200020022004200620082010 Years Figure 2: Annual precipitation from 1972 to 2011 at the Ochotnica Górna station based on the classification of precipitation ranges proposed by Kaczorowska (1962). Precipitation[mm] XIXII I II IIIIV V 80 60 40 20 0 Month Figure 3: Average monthly precipitation from 1972 to 2011 at the Ochotnica Górna station (Institute…2015). 4 Results 4.1 Runoff coefficient and the probability of maximum discharges The runoff coefficient is a key concept in hydrology and floods, and is an important diagnostic variable forcatchmentresponse. Examinationofrunoffcoefficientsisusefulforcatchmentcomparisontounder-standhowdifferentlandscapesfilterrainfallintoafloodevent(Holko,HerrmannandKulasova2006;Marchi et al.2010).AccordingtoSchaake(1990),itispossibletodeterminethesizeoffloodsbasedonrunoffand precipitation. The average runoff coefficient from 1972 to 2011 was 62.8%. The highest runoff coefficient (91.8%) was recorded in 1980 (Figure 4). The greater variation of runoff in western Europe, compared to eastern Europe, reflects the greater vari­ abilityintopography,andhencerainfall.AcrossmostoflowlandEurope,runoffisbetween25and45%,whereas itexceeds70%inhighprecipitationareassuchastheAlps(Arnell1999;Magnuszewski2000;Marchietal.2010). TherunoffcoefficientsintheOchotnicacatchmentdonotshowanysignificanttrends.Similarresults were obtained by Pekarova, Miklanek, and Peka (2006) for European rivers over the last 150 years. Therunoffirregularitycoefficient(theratiooftheannualmaximumtominimumrunoff)intheOchotnica River ranged from 3.4mmin 1978 to 17.9mm in 2000, and it shows an increasing trend (Figure 4). High recent values of the coefficient are due to the great diversity of total monthly precipitation. Compared to otherCarpathianrivers,thiscoefficientisnothigh,anditisdeterminedbyacontinuouswatersupplydur­ing the summer and the autumn lows. TheaveragedischargeintheOchotnicaRiverinthemultiyearperiodanalyzedwas1.81m3/s.Ziemońska (1973)proposedeightriverclasseswithdifferentaveragedischargesinthePolishCarpathians.TheOchotnica Riverisinthesecondclass,withdischargesrangingfrom1to3m3/s.Onaverage,forapproximately234days annually, the Ochotnica River had a discharge of 0.5 to 2m3/s, and the discharge was 2 to 5m3/s for sev-enty-sevendays(Figure5).Adischargegreaterthan10m3/swasrecordedforanaverageoffourdays.There arenodifferences in averagedischarges duringthe summerand winter hydrological half-year during the period analyzed. Figure 4: Runoff coefficient (Rc) and irregular runoff coefficient (Irc) in the Ochotnica River from 1972 to 2011. Figure 5: Frequency of average daily discharge in the Ochotnica River from 1972 to 2011. OnthebasisoffortyyearsofobservationsofwaterdischargeintheOchotnicaRiver,atheoreticalprob­abilitycurvewasplottedforthemaximumdischargeusingaPearsondistribution(TypeIII),startingfrom avalueof1%(Table1).Maximumdischargesaredirectlyrelatedtofloods(PattonandBakerKonrad1976). Table 1: Probability (%) of maximum discharges (m3/s) and recurrence period (T) in the Ochotnica River based on the Pearson distribution (Type III). Probability (%) Discharge (m3/s) T (Year) 1 92 100 2 80 50 5 70 20 10 38 10 20 25 5 50 15 2 100 4 1 4.2 Discharge regime Adischargeregimedescribestheaverageseasonalbehaviorofariver,asdeterminedbyitsgeneticsources and its ambient climate. The discharge regime is a useful tool for identifying spatial and temporal varia­tionsin themagnitude andseasonality ofdischarge, andfor determining theperiods more susceptibleto floods(Wrzesiński2012).TheOchotnicaRiverisanexampleofariverwithacomplex,primary,snow-rain regime withitspeak dischargein thesecond half of winter and in the summer(Figure 6). The first, high­er discharge peak occurs in April, and the second, lower one in July. Low discharges in the autumn and winteraretheconsequenceofreducedprecipitation(especiallyintheautumn)andsnowretention.Discharge coefficient values in the Ochotnica River were close to k = 1.5 in the spring, which is characteristic of the Carpathian rivers west of the Dunajec River (Chełmicki, Skąpski and Soja 1998–1999). IntheOchotnicaRiver,thespringmonths(March,April,Cv=0.4)arecharacterizedbythelowestvari-ability in discharge. This relationship is due to a high degree of reproducibility in the water supplied by snowmelt(Chełmicki,SkąpskiandSoja1998–1999).Thegreatestdischargevariability(Cv>0.7)isinMay, September, and December. High values of the coefficient of variation in May and September are associat­edwithlimitedrecurrenceoffloodsinindividualyears.InDecember,winterthawingmaybeadestabilizing factor. The average value of the coefficient of variation from 1972 to 2011 is 0.63, indicating high stability of the rhythm of discharge in the river analyzed. Dischargecoefficient [k] Coefficientofvariation[C v] 2.0 1.5 1.0 0.5 0.0 C v k XI XII I II III IV V VI VIIVIIIIX X Month Figure 6: Differences in the monthly annual course of the discharge coefficient (k) and coefficient of multiyear variability of monthly discharge (C ) for hydrological years from 1972 to 2011 in the Ochotnica River. v 5 Discussion 5.1 Characteristics of floods Low, normal, and high floods occurring in the hydrological winter and summer half-years were ana­lyzed. UsingthecriteriafordefiningfloodsgivenintheMethodssection,it was assumedthat lowfloods occur when the culminating discharge is greater than 3.26m3/s during winter and 4.22m3/s in summer (Table 2). Table2:QuantitativecharacteroffloodsintheOchotnicachannelfrom1972to2011. Measure Value Meandischarge 1.8m3/s Meanspecificdischarge 0.017m3/s/km2 Maximumdailydischarge 79.8m3/s Winterhydrologicalhalf-year Lowflood 3.26–3.80m3/s Normalflood 3.80–11.94m3/s Highflood >11.94m3/s Summerhydrologicalhalf-year Lowflood 4.22–4.74m3/s Normalflood 4.74–16.40m3/s Highflood >16.40m3/s Maximumdurationofflood 55days Meandurationoffloodinwinter/summerhydrologicalhalf-year 24days7h/12days17h In the forty years of observations (1972–2011), 295 floods were calculated. The average for each hydrological yearwas seven floods. Thereis a decreasingtrend ofthe flood numbersinthehydrological winter half-year and an increasing trend in the summer half-year. The trends are not statistically sig­nificant. Lowfloodsaccounted for approximately 17% and15%ofall floodsinthewinter andsummerhydro-logical half-years. High floods in the entire multiyear period accounted for only 14% of the total number of floods (12% in the winter hydrological half-year and 15% in the summer half-year; Figure 7). Floodsarecloselylinkedtothetypeofwatersourceflowingintotheriverchannel.Themagnitudeand courseoffloodsinwinterarerelatedtotheamountofwaterfrommeltingsnowinatimeunit.Rapidsnowmelt oftencausesmajorspringfloods.Inmountainousregions,springfloodsareusuallynotashighasthesum­merrainfallfloods, but theyhave an increased frequencyof single snowmelt floods(January–March) and floodsfrommixedwatersupply(April).Snowmeltfloodformation(especiallythaw)isinfluencedbyasouth­erncatchmentexposure.Inthewinterhalf-yearduringtheperiodanalyzed,146floodswererecorded.The averageflooddurationwas24.29days(7%oftheyear),longerthansummerfloods.Thisisconnectedwith the water supply from various parts of the asymmetric catchment. Over the forty years, April was charac­terized by the highest number of floods (forty-nine). Summerfloodsaremoredynamicthanwinterfloods. Inthemultiyearperiodanalyzed,atotalof149 floods were recorded in the hydrological summer half-year. During this time, floods are caused by tor­rential and extreme rainfall. Summer floods occurred in the channel of the Ochotnica River irregularly andlastedshorterthanthefloodsduringthewintermonths(anaverageof12.71days).Highfloodsaccount­edfor15%ofthese,or2percentagepointsmorethaninthehydrologicalwinterhalf-year.Theaveragevalue ofthemaximumdailydischargeduringall of thefloodsinsummerhalf-yearamountedto16.4m3/s,and theabsolutemaximumdischargeof79.8m3/swasrecordedonMay2nd,1989.Thiswas144timesgreater than the average discharge. 70.55 80 70 60 50 40 30 20 10 0 Summer hydrologicalyear Figure 7: Frequency of flood types in the Ochotnica River in the winter (November–April) and summer (May–October) hydrological half-years from 1972 to 2011. Frequence[%] Winter hydrological year 5.2 The dynamics of the Ochotnica channel Analysis of changes in the position of river channel bottoms can be performed based on the minimum conditions of the river (e.g. Wiejaczka and Kijowska-Strugała 2015; Tamang and Mandal 2015). The use of data on water levels in the river provides reliable information about the direction of change (incision or raising) and its intensity. Incision is a common response of alluvial channels that have been disturbed suchthattheycontainexcessamountsofflowenergyorstreampowerrelativetothesedimentload(Simon and Rinaldi 2006). If the river capacity is less than the load, deposition would be expected. On the basis of an analysis of the minimum water levels from 1972to 2011, two periods can be iden­tifiedwithdifferenttendenciesinchangingthepositionoftheOchotnicachannelbottom.Thefirstcovers theperiodfrom1972to1996,whenaggradationwasthepredominantprocess,whereasfrom1997to2011 incision dominated (Figures 8, 9). Acleardecrease,by70cm,duringthelowestminimumwaterlevelin1997,ascomparedto1996,was duetoextremefloods.InJuly,themaximumwaterlevelwas344cm,correspondingtoadischargeof17.6m3/s. Suchahighdischargewascausedbydailyrainfallexceeding70mm. InJuly,therainfalltotalwas291mm and was 2.5 times higher than the average value from 1972 to 2011 (Froehlich 1998; Bucała 2012). Between1972and1996,theminimumwaterlevelsrangedfrom186cm(1973)to286cm(1993),where­asbetween1997and2011theyrangedfrom158cm(2011)to216cm(2003).In1983,atthelevelof276cm, the discharge recorded was 3.16m3/s, whereas it was only 0.45m3/s in 1996. This proves that the bed of theOchotnicarosebetween1972and1996.Thecourseofthelowestmonthlywaterlevelsduringthisperi­od also shows a tendency to raise the channel bottom, amounting to 3.9cm/year (Figure 8). In 1997, the lowestwaterlevelwas206cm,withadischargeof0.81m3/s,andin2010atthesamewaterlevelthedischarge recordedwas2.24m3/s.Theexamplesshowthatthesamewaterlevelinthemultiyearperiodcorresponds toincreasinglyhigherdischarges,whichisclearevidenceoftheriverchanneldeepening.Theaveragerate of the annual lowest water level decreasing from 1997 to 2011 is 3.2cm/year (Figure 9). Year Figure 8: Minimum and maximum annual water level in the Ochotnica River from 1972 to 1996. 1972 1973 1974197519761977 1978 1979198019811982 1983 1984198519861987 1988 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 1989 1990 19911992 2008 2009 1993 1994 1995 2010 2011 1996 Year Figure 9: Minimum and maximum annual water level in the Ochotnica River from 1997 to 2011. ProcessesoccurringinrecenttimesintheCarpathianenvironment(e.g.,incisionofchannelbottoms) are related to an increase in the sum and intensity of precipitation and are probably caused by changes in landuse(Klimek1987;Kijowska-StrugałaandDemczuk2015).Land-usechangesleadingtoforestexpan­sionattheexpenseofagriculturallandand,relatedtothis,conversionofbraidedriverstoincised,single-thread channels have also been noted in other European mountains (Wohl 2006). 6 Conclusion Intermsofthetypes,duration,variability,andmagnitudeoffloods,theforty-yearperiodanalyzed(1972–2011) showsthebasicregularitiesobservedinsmallmountaincatchmentsinEurope. Theanalysisofmeasured floods does not indicate an increasing frequency. The runoff coefficient and number of floods in the last two decades do not show significant differences with regard to values that occurred in the previous two decades.SimilarresultshavebeenobservedinothermountainriversinEurope.However,intheOchotnica River in the last two decades a greater number of high floods has been noted. This can be related to an increased sum and intensity of precipitation over the last forty years, which is also documented in other European catchments. FloodsontheOchotnicaRiverusuallyoccurinAprilandJune,whichisconnectedwithitssnow-rain river regime. Winter floods last longer than summer floods. This is related to the way the river channel is supplied with water from snowmelt in various parts of its asymmetric catchment. Theanalysisoftheminimumwaterlevelsshowedsignificantchangesinthedynamicsoftheposition of the Ochotnica River channel bottom over time. Since 1997, the predominant process in the channel, asinthecaseofotherCarpathiansrivers,hasbeenincision.ThedeeperosionobservedinCarpathianrivers in the last decade is probably associated with changes in land use (a decrease in arable land and increase in forest area), which have intensified due to the economic transformation of the country and, in recent years, Poland’s accession to the EU. 7 References Alpert,P.,Ben-Gai,T.,Baharad,A.,Benjamini,Y.,Yekutieli,D.,Colacino,M.,Diodato,L.,Ramis,C.,Homar,V., Romero,R.,Michaelides,S.,Manes,A.2002:TheparadoxicalincreaseofMediterraneanextremedaily rainfallinspiteofdecreaseintotalvalues.Geophysicalresearchletters29-11.DOI:https://doi.org/10.1029/ 2001GL013554 Arnaud-Fassetta,G.,Cossart,E.,Fort,M.2005:Hydro-geomorphichazardsandimpactofman-madestruc­turesduringthecatastrophicfloodofJune2000intheUpperGuilcatchment(Queyras,SouthernFrench Alps). Geomorphology 66, 1-4. DOI: https://doi.org/10.1016/j.geomorph.2004.03.014 Arnell,N.W.1999:TheeffectofclimatechangeonhydrologicalregimesinEurope:acontinentalperspective. Global environmental change 9-1. DOI: https://doi.org/10.1016/S0959-3780(98)00015-6 Barredo,J.I.2007:MajorflooddisastersinEurope1950–2005.NaturalHazards42-1.DOI:https://doi.org/ 10.1007/s11069-006-9065-2 Bezak, N., Horvat, A., Šraj, M. 2015: Analysis of flood events in Slovenian streams. Journal of Hydrology and Hydromechanics 63-2. DOI: https://doi.org/10.1515/johh-2015-0014 Bork, H. R., Bork, H., Dalchow, C., Faust, B., Piorr, H. P., Schatz, T. 1998: Landschaftsent-wicklung in Mitteleuropa, Wirkungen des Menschen auf Landschaften. Stuttgart. Bronstert, A. 2003: Floods and climatic change: interactions and impacts. Risk Analysis 23-3. DOI: https://doi.org/10.1111/1539-6924.00335 Brookes,A.1987:RiverchanneladjustmentdownstreamfromchannelizationworksinEnglandandWales. Earth Surface Processes and Landforms 12-4. DOI: https://doi.org/10.1002/esp.3290120402 Bryndal, T. 2014: A method for identification of small Carpathian catchments more prone to flash flood generation:Basedontheexampleofsouth-easternpartofthePolishCarpathians.CarpathianJournal of Earth and Environmental Sciences 9-3. Bucała, A. 2012: Contemporary environmental changes of Jaszcze and Jamnestream valleysin theGorce Mountains. Geographical Studies 231. Bucała, A., Budek, A., Kozak, M. 2015: The impact of land use and land cover changes on soil propertiesandplantcommunitiesintheGorceMountains(WesternPolishCarpathians),duringthepast50years.Zeitschrift fur Geomorphologie 59-2. DOI: https://doi.org/10.1127/zfg_suppl/2015/S-59204 Chełmicki,W.,Skąpski,R.,Soja,R.1998–1999:HydrologicalregimeofCarpathianriversinPoland.Folia Geographica, series Geographia-Physica 29-30. Christensen, J. H., Christensen, O. B. 2003: Climate modelling: Severe summertime flooding in Europe. Nature 421. DOI: https://doi.org/10.1038/421805a Dębski, K. 1954: Prawdopodobieństwo zjawisk hydrologicznych i meteorologicznych. Warszawa. Frandofer, M., Lehotský, M. 2011: Channel adjustment of a mixed bedrock-alluvial river in response torecent extreme flood events (the upper Topľa river). Geomorphologia Slovaca et Bohemica 11-2. Froehlich, W. 1998: Transport rumowiska i erozji koryta potoków beskidzkich podczas powodzi w lipcu1997 roku. Powódź w dorzeczu górnej Wisły w lipcu 1997 roku. Kraków. Gaál, L., Szolgay, J., Kohnová, S., Parajka, J., Merz, R., Viglione, A., Blöschl, G. 2012: Flood timescales:Understandingtheinterplayofclimateandcatchmentprocessesthroughcomparativehydrology.WaterResources Research 48-4. DOI: https://doi.org/10.1029/2011WR011509 Gorczyca,E.,Krzemień,K.,Wrońska-Wałach,D.,Boniecki,M. 2014:Significanceofextremehydro-geo­morphologicaleventsinthetransformationofmountainvalleys(NorthernSlopesoftheWesternTatraRange,CarpathianMountains,Poland).Catena121.DOI:https://doi.org/10.1016/j.catena.2014.05.004 Holko,L.,Herrmann,A.,Kulasova,A.2006:ChangesinrunoffregimesinsmallcatchmentsinCentralEurope:Are there any? International Association of Hydrological Sciences 308. Institute of Meteorology and Water Management, 2015. Rainfall data 1972–2011. Warszaw. Kaczorowska, Z. 1962: Opady w Polsce w przekroju wieloletnim. Geographical Studies 33. Kijowska-Strugała,M.2012:ImpactofdownpoursonfluvialprocessesinthePolishCarpathiansasexem­plifiedbytheBystrzankastream.StudiaGeomorphologicaCarpatho-Balcanica46-1.DOI:https://doi.org/10.2478/v10302-012-0002-2 Kijowska-Strugała M. 2015: Transport of suspended sediment in the Bystrzanka stream (Polish FlyschCarpathians) under changing antropopressure. Geographical Studies 247. Kijowska-Strugała, M., Demczuk, P. 2015: Impact of land use changes on soil erosion and deposition inasmallpolishcarpathianscatchmentinlast40years.CarpathianJournalofEarthandEnvironmental Sciences 10-2. KleinTank,A.M.G.,Koennen,G.P.2003:Trendsinindicesofdailytemperatureandprecipitationextremesin Europe, 1946–99. Journal of Climate 16-22. DOI: https://doi.org/10.1175/1520-0442(2003)016<3665:TIIODT>2.0.CO;2 Klimek,K.1987:Man’simpactonfluvialprocessesinthePolishWesternCarpathians.GeografiskaAnnaler69-1. DOI: https://doi.org/10.2307/521379 Kondolf, G. M., Piégay,H.,Landon,N. 2002:Channelresponseto increased and decreasedbedloadsupplyfromlandusechange:contrastsbetweentwocatchments.Geomorphology45,1-2.DOI:https://doi.org/10.1016/S0169-555X(01)00188-X Krzemień,K.1984:WspółczesnezmianymodelowaniakorytpotokówwGorcach.GeographicalStudies59. Liébault,F.,Piégay,H.2002:Causesof20thcenturychannelnarrowingonmountainandpiedmontriversofsoutheasternFrance.EarthSurfaceProcessesandLandforms27-4.DOI:https://doi.org/10.1002/esp.328 Magnuszewski, A. 2000: Hydrology and water quality of European rivers. The Waterscape. Uppsala. Malarz,R.2005:EffectsoffloodabrasionofCarpathianalluvialgravels.Catena64-1.DOI:https://doi.org/ 10.1016/j.catena.2005.07.002 Marchi, L., Borga, M., Preciso, E., Sangati, M., Gaume, E., Bain, V., Delrieu, G., Bonnifait, L., Pogačnik, N. 2009: Comprehensive post-event survey of a flash flood in Western Slovenia: observation strategyand lessons learned. Hydrological processes 23-26. DOI: https://doi.org/10.1002/hyp.7542 Marchi, L., Borga, M., Preciso, E., Gaume, E. 2010: Characterisation of selected extreme flash floods inEuropeandimplicationsforfloodriskmanagement.JournalofHydrology394,1-2.DOI:https://doi.org/10.1016/j.jhydrol.2010.07.017 Mudelsee, M., Börngen, M., Tetzlaff, G., Grünewald, U. 2004: Extreme floods in central Europe over thepast500years:Roleofcyclonepathway»ZugstrasseVb”.JournalofGeophysicalResearch:Atmospheres 109-23. DOI: https://doi.org/10.1029/2004JD005034 New,M.,Hulme,M.,Jones,P. 1999:Representingtwentiethcenturyspace-timeclimatevariability.Part I: development of a 1961–90 mean monthly terrestrial climatology. Journal of Climate 12-3. DOI:https://doi.org/10.1175/1520-0442(1999)012<0829:RTCSTC>2.0.CO;2 Niemirowski, M. 1974: Dynamika współczesnych koryt potoków górskich. Geographical Studies 34. Ogden,F.L.,Dawdy,D.R.2003:PeakdischargescalinginsmallHortonianwatershed.JournalofHydrologic Engineering 8-2. DOI: https://doi.org/10.1061/(ASCE)1084-0699(2003)8:2(64) Ouarda, T. B. M. J., Cunderlik, J. M., St-Hilaire, A., Barbet, M., Bruneau, P., Bobée, B. 2006: Data-based comparison of seasonality-based regional flood frequency methods. Journal of Hydrology 330, 1-2. DOI: https://doi.org/10.1016/j.jhydrol.2006.03.023 Ozga-Zielińska, M., Brzeziński, J. 1994: Hydrologia stosowana. Warszawa. Parajka, J., Kohnová, S., Bálint, G., Barbuc, M., Borga, M., Claps, M., Cheval, S., Dumitrescu, A., Gaume, E., Hlavčová, K., Merz, R., Pfaundler, M., Stancalie, G., Szolgay, J. Blöschl, G. 2010: Seasonal charac­teristics of flood regime across the Alpine-Carpathian range. Journal of Hydrology 349, 1-2. DOI: https://doi.org/10.1016/j.jhydrol.2010.05.015 Pardé, M. 1957: Rzeki. Warszawa. Patton,P.C.,Baker,V.R.1976:Morphometryandfloodsinsmalldrainagebasinssubjecttodiversehydro­geomorphiccontrols.WaterResourcesResearch12-5.DOI:https://doi.org/10.1029/WR012i005p00941 Pekarova, P., Miklanek, P., Pekar, J. 2006: Long-term trends and runoff fluctuations of European rivers. International Association of Hydrological Sciences 308. Pociask-Karteczka, J. 2011: River runoff response to climate changes in Poland (East-Central Europe). International Association of Hydrological Sciences 344. Ramos,M.H.,Bartholmes,J.,Thielen-delPozo,J.2007:Developmentofdecisionsupportproductsbased on ensemble forecasts in the European flood alert system. Atmospheric Science Letters 8-4. DOI: https://doi.org/10.1002/asl.161 Rinaldi, M. 2003: Recent channel adjustments in alluvial rivers of Tuscany, central Italy. Earth Surface Processes and Landforms 28-6. DOI: https://doi.org/10.1002/esp.464 Ruiz-Villanueva,V.,Díez-Herrero,A.,Stoffel,M.,Bollschweiler,M.,Bodoque,J.M.,Ballesteros,J.A.2010: Dendrogeomorphicanalysisofflashfloodsinasmallungaugedmountaincatchment(CentralSpain). Geomorphology 118, 3-4. DOI: https://doi.org/10.1016/j.geomorph.2010.02.006 Schaake, J. C. 1990: From climate to flow. New York. Simon,A.,Rinaldi,M.2006:Disturbance,streamincision,andchannelevolution:Therolesofexcesstrans­portcapacityandboundarymaterialsincontrollingchannelresponse.Geomorphology79,3-4.DOI: https://doi.org/10.1016/j.geomorph.2006.06.037 Sivapalan,M.,Blöschl,G.,Merz,R.,Gutknecht,D.2005:Linkingfloodfrequencytolong-termwaterbal­ance:Incorporatingeffectsofseasonality.WaterResourcesResearch41-6.DOI:https://doi.org/10.1016/ 10.1029/2004WR003439 Starkel, L. 1972: Karpaty zewnętrzne. Geomorfologia Polski. Warszawa. Starkel,L.1976:Theroleextreme(catastrophic)meteorologicaleventsincontemporaryevolutionofslopes. Geomorphology and Climate. Chichester. Tamang,L.,Mandal, D. K. 2015:Bed materialextraction and its effects on theformsandprocesses ofthe lower Balason River in the Darjeeling Himalayas, India. Geographia Polonica 88-3. https://doi.org/ 10.7163/GPol.2015.3 Wiejaczka,Ł.,Kijowska-Strugała,M.2015:Dynamicsofthechannelbedslevelinmountainriversinthelight of the minimum water stages analysis. Carpathian JournalofEarth andEnvironmental Sciences 10-4. Wohl,E.2006:Humanimpactstomountainstreams.Geomorphology79,3-4.DOI:https://doi.org/10.1016/ j.geomorph.2006.06.020 Wrzesiński, D. 2013: Uncertainty of Flow Regime Characteristics of Rivers in Europe. Quaestiones Geographicae 32-1. DOI: https://doi.org/10.2478/quageo-2013-0006 Wyżga,B.,Zawiejska,J.,Radecki-Pawlik,A.2015:Impactofchannelincisiononthehydraulicsoffloodflows: Examples from Polish Carpathian rivers. Geomorphology 272-1. DOI: https://doi.org/10.1016/ j.geomorph.2015.05.017 Van der Ploeg, R., Schweigert, P. 2001: Elbe river flood peaks and postwar agricultural land use in East Germany. Naturwissenschaften 88-12. DOI: https://doi.org/10.1007/s00114-001-0271-1 Yin, H., Li, C. 2001: Human impact on floods and flood disasters on the Yangtze River. Geomorphology 41, 2-3. DOI: https://doi.org/10.1016/S0169-555X(01)00108-8 Ziemońska, Z. 1973: Stosunki wodne w Polskich Karpatach Zachodnich. Geographical Studies 103.