《全球变化科学》课程教学资源（讲义）03 Indicators for estimating the sub-catchments’ contribution to maximum flow during flood events in the Jiu River Basin

WuhanUniversityofTechnologyDepartmentofSpatial InformationandPlanningSchoolofResourcesandEnvironment EngineeringIndicators for estimating the sub-catchments' contribution tomaximum flow during flood events in the Jiu River BasinGabrielaAdinaMOROSANU-MITOSERIUInstituteofGeographyof theRomanianAcademy,Romaniagabriela.adina.m@gmail.com

Indicators for estimating the sub-catchments’ contribution to maximum flow during flood events in the Jiu River Basin 1 Wuhan University of Technology Department of Spatial Information and Planning School of Resources and Environment Engineering Gabriela Adina MOROȘANU-MITOȘERIU Institute of Geography of the Romanian Academy, Romania gabriela.adina.m@gmail.com

OutlineContextObjectiveStudy areaDataMethodology·DischargeThreshold calculationSelectionofthefloodsDevelopmentoftheindicatorsResultsConclusions

Outline Context Objective Study area Data Methodology • Discharge Threshold calculation • Selection of the floods Development of the indicators Results Conclusions 2

ContextThefloodvolumeonthemainriverissuppliedbythevolumescoming,inan unevenand unpredictable way,from thetributaries.Inahydrographicbasin,the sourceareas andthepropagationpathsofflood volumes varyseasonallyand alsoaccordingto exceptional events.Sub-catchments with high discharge rates are not always the keycontributorstofloodriskonthemainriverfurtherdownstream.Althoughthe spatial distribution of precipitationis a keyfactor in theformationof flood waves,theways inwhichfloodvolume isdelivereddoes notalwaysfollowthe rainfall behaviour.Flood events not only mobilize large volumes of water, but also sediments and theyare,thus,responsibleforbuilding alluvial riverbanks.OBJECTIVETo develop an indicator-based methodology allowing to identify the contributions of the mainsub-catchments during the flood events, by usingthe average dailyflow

3 Context OBJECTIVE To develop an indicator-based methodology allowing to identify the contributions of the main sub-catchments during the flood events, by using the average daily flow. The flood volume on the main river is supplied by the volumes coming, in an uneven and unpredictable way, from the tributaries. In a hydrographic basin, the source areas and the propagation paths of flood volumes vary seasonally and also according to exceptional events. Sub-catchments with high discharge rates are not always the key contributors to flood risk on the main river further downstream. Although the spatial distribution of precipitation is a key factor in the formation of flood waves, the ways in which flood volume is delivered does not always follow the rainfall behaviour. Flood events not only mobilize large volumes of water, but also sediments and they are, thus, responsible for building alluvial riverbanks

Study area23°0'0'E24°0'0′'EUraingJiuRiverBasinHungarRep.otJiuRiverBasinloidovagul MareMaxPian2519mVadeni-Ta.JiSaReservoirsAhinudes(mDanceMac2544Bulcaria050100200KmMnOJiu RiverBasin:Legend. SWRomania,Danubetributary,5 Ju River BasinCarpathianwatershedRiversArea~10,080km2,Lu~331kmAverageMain tributary watershedsrivernetworkdensity~0,39km-km-2Amaradia-Main rivers:Jiu,Eastern Jiu,Motru(F=Amaradia PietroasaArgetoaia1895 km2), Gilort (1358km2),Amaradia,LegendCioianaTismanaGilort2MainRivers Qavg.Ju E (3,24 m'-s-1 - Campu ui Neag g.s.;JiltJiu Estla 95 m-s-1-Zaval g.s.) and Qmax.Ju = 2000Elevations (m)JiuOuestm3.s-1Podarig.s.High:2519Motru-Different centers of origin of floods withinRaznictheriver basin dueto the different hydro-Low:23Susita0TismanaandmeteorologicalmorphometricIKm051020Kmcharacteristics of the sub-basins.23*0/0°E2400°E

4 Study area Jiu River Basin:  SW Romania, Danube tributary, Carpathian watershed  Area ~10,080 km2 , LJiu ~ 331 km Average river network density ~ 0,39 km∙km-2  Main rivers: Jiu, Eastern Jiu, Motru (F = 1895 km2 ), Gilort (1358 km2 ), Amaradia, Tismana  Qavg. Jiu ∈ (3,24 m³∙s-1 - Câmpu ui Neag g.s.; la 95 m³∙s-1 – Zăval g.s.) and Qmax. Jiu = 2000 m³∙s-1 – Podari g.s.  Different centers of origin of floods within the river basin due to the different hydro￾meteorological and morphometric characteristics of the sub-basins. Jiu River Basin

DataGeneralcharacteristicsoftheselectedriversandtheirwatershedsCatchmentAverageSide of the JiuGaugingAverage annualMaximum dailyAnalysisRiverRiverlevelstationdischarge (m's-)discharge (m’s-1)area (km2)elevation (m)RNiRaznic0,93475201Breasta134,4RNiArgetoaiaScaiesti0.3556,6249,7227,67LNi2,15859273AmaradiaAlbesti293,3RN,12,781700384MotruFata Motrului917,6RN2JiltTurceni1,180,3376540LN2590Gilort10,2377,31027TurbureaRN29.19314387TismanaCalnic356,82RN2Bistrita4,23135270540TelestiR154N2Runcu3,06111,2851StolojaniRN2Susita2,1779Vaidei43,81055L460N3Livezeni7,73104,21256JiudeI'EstRN35021134Jiudel'OuestIscroni10,29340,5Jiu9253446NiPodari84,571940,4DownstreamJiuFiliasi63,651434,55239563Up/DowntsreamN, / N,JiuSadu20,26246,712551066Up/DowntsreamN, / N3:DailyDischargedata:ABAJIU5.Precipitationdata:ROCADAGriddedDataset(extractionofupstreamdailyrainfallvaluesforeachg.s.)

5 River Gauging station Average annual discharge (m3 s -1 ) Maximum daily discharge (m3 s -1 ) Catchment area (km2 ) Average elevation (m) Side of the Jiu River Analysis level Raznic Breasta 0,93 134,4 475 201 R N1 Argetoaia Scăiești 0.35 56,6 249,7 227,67 R N1 Amaradia Albești 2,15 293,3 859 273 L N1 Motru Fața Motrului 12,78 917,6 1700 384 R N1 Jilț Turceni 1,1 80,3 376 540 R N2 Gilort Turburea 10,2 377,3 1027 590 L N2 Tismana Câlnic 9.19 314 387 356,82 R N2 Bistrița Telești 4,23 135 270 540 R N2 Runcu Stolojani 3,06 111,2 154 851 R N2 Șușița Vaidei 2,17 43,8 79 1055 R N2 Jiu de l’Est Livezeni 7,73 104,2 460 1256 L N3 Jiu de l’Ouest Iscroni 10,29 340,5 502 1134 R N3 Jiu Podari 84,57 1940,4 9253 446 Downstream N1 Jiu Filiaşi 63,65 1434,5 5239 563 Up /Downtsream N1 / N2 Jiu Sadu 20,26 246,7 1255 1066 Up /Downtsream N2 / N3 Data General characteristics of the selected rivers and their watersheds • Daily Discharge data: ABA JIU • Precipitation data: ROCADA Gridded Dataset (extraction of upstream daily rainfall values for each g.s.)

RiverGauging stationAcronymeDataJiuldeVestJiul de EstLevel3 (uppersector)-Referencegaugingstation-Sadu (SJ)L3JiuSJSaduTJOLEIscroni10Jiu de FOuestUELivezeniSIJiu de I'EstSusitaB.1.3Intermediary drainage areasTismanaVSLevelz (middlesector)-Referencegaugingstation-Flliasi (Fl)FiliasiJiuFJTVSVaideiSusitaJiulL2GTGodinestiTismana所Tismana riverTBTelestiBistritabasinCO卫CeleiOrleaGilort(TT)SRStolojaniRuncuTGMotruJiltTJTurceniFTGTulbureaGilortFMSJSaduJiuAngetoaiB.1.2Intermediary drainage areasAmaradiaSALevel1 (lowersector)-Referencegaugingstation-Podari(P)RaznicAAL1JiuPJPodariBRMotruFMFataMotruluiSAScaiestiArgetoaiaPIBreastaBRRaznicAlbestiAmaradiaAAJiuFJFiliasinubeB.1.1Intermediary drainage areas3levelsof referencerelatedtotheexitsofthethreesectorsofJiuRiverDailydischargedataatthegaugingstations situateddownstreamthepotentiallycontributingcatchmentsApartfromthetributaryriverbasins,theintermediary drainageareasalong themain river, between the confluences,werealso considered6

Data 6 Gauging station River Acronyme Level 3 (upper sector) – Reference gauging station - Sadu (SJ) Sadu Jiu SJ Iscroni Jiu de l’Ouest IJO Livezeni Jiu de l’Est IJE Intermediary drainage areas B.I.3 Level 2 (middle sector) – Reference gauging station - Filiași (FJ) Filiași Jiu FJ Vaidei Șușița VS Godinești Tismana Tismana river basin (TT) GT Telești Bistrița TB Celei Orlea CO Stolojani Runcu SR Turceni Jilț TJ Tulburea Gilort TG Sadu Jiu SJ Intermediary drainage areas B.I.2 Level 1 (lower sector) – Reference gauging station - Podari (PJ) Podari Jiu PJ Fața Motrului Motru FM Scăiești Argetoaia SA Breasta Raznic BR Albești Amaradia AA Filiași Jiu FJ Intermediary drainage areas B.I.1 • 3 levels of reference related to the exits of the three sectors of Jiu River • Daily discharge data at the gauging stations situated downstream the potentially contributing catchments • Apart from the tributary river basins, the intermediary drainage areas along the main river, between the confluences, were also considered

Data.Hydrological data availablefor Tismana and Amaradia Pietroasa rivers23'010°E240/0°B.V. de I'AmaradiaB.V.de la TismanaJiuPietroasaOhabaNameGodinestiDistancefromthe23,1km26,1kmFunctional gaugingconfluencewithJiuR.stationsWorking period1954-present1988-presentN.0.0calniclasi-GorjNomVb.h.maradiaDistancefromthe4,9km1,2kmClosed gaugingPletroasaconfluencewith JiuRstationsb.h.Tismana1968-19981988-1998Working periodLes3J.Podarig.s.-mainreferencegaugingMain tribstationAmiAmiArg:Studyperiod:2000-2016Cioi国GilcMissingdata forkeygaugingstations(onJitJiuPodarig.Tismana & Amaradia Pietroasa rivers)JiuMot福estimation.Onecannot estimatetheirRazSuscontribution by knowing their drainageTisrareas only.123°0r0*E240/0°

Data 7 Podari g.s. • Podari g.s. – main reference gauging station • Study period : 2000 – 2016 • Missing data for key gauging stations (on Tismana & Amaradia Pietroasă rivers) estimation. One cannot estimate their contribution by knowing their drainage areas only. B.V. de la Tismana B.V. de l’Amaradia Pietroasă Functional gauging stations Name Godinești Ohaba Distance from the confluence with Jiu R. 23,1 km 26,1 km Working period 1954 – present 1988 - present Closed gauging stations Nom Câlnic Iasi-Gorj Distance from the confluence with Jiu R. 4,9 km 1,2 km Working period 1968 – 1998 1988 - 1998 . Hydrological data available for Tismana and Amaradia Pietroasă rivers

EstimationofthedischargeseriesofTismanaandAmaradiaPietroasaRivers(2000-2016)DSGR4J1Drainfall-runoffmodelEPTTTTTT(developedbyCemagrefIRSTEA,France)interceptionGR4J-four-parameterdailylumpedEnPnhydrological model [Perrin et al., 2003], in RStudio,with《airGR》package,using ETPPsEsPn-Psformulaproposed byOudin (2003):-X1 - maximum capacity of the production reservoir(mm);-X2undergroundwatershedexchangeratesPerccoefficient (mm);0.1-X3 - maximum capacity for 1 day routing reservoirHUIHU(mm);- X4-base time of the unit hydrogramme - HU1 (day).EQ97F(X2)FX2F0WO54Ao0OQdExampleforTismanaRiver30-days roling meannonexceedance prob. (-)0oheeeyedtnwmm/n

Estimation of the discharge series of Tismana and Amaradia Pietroasă Rivers (2000 – 2016) GR4J 1D rainfall – runoff model (developed by Cemagref IRSTEA, France) 8 GR4J - four-parameter daily lumped hydrological model [Perrin et al., 2003], in R Studio, with « airGR » package, using ETP formula proposed by Oudin (2003) :  X1 – maximum capacity of the production reservoir (mm);  X2 – underground watershed exchange rates coefficient (mm);  X3 – maximum capacity for 1 day routing reservoir (mm);  X4 – base time of the unit hydrogramme - HU1 (day). Example for Tismana River

MethodologyHow do we define major floods.Magnitude-FrequencyrelationshipMajorMaximumdischargeFlood events spatio-orthresholdingThe erosive ortemporaldistributionaccumulativeeffectsonI-theriverbanks1Bank overflowing-capacityofthemaximumdischarge-Thetemporaloccurrence1How do we define major floods?Wheredotheycomefrom?-andspatialdistributionof-Wherearetheygoing?floods with significant-socio-economiceffects1Whichfloodsshouldweselectforstudying?the upstream contribution to theirformation?andtheupstream-downstreamrelationshipintheirpropagation?

Methodology 9 Major Flood events spatio￾temporal distribution Maximum discharge thresholding Magnitude – Frequency relationship or The erosive or accumulative effects on the riverbanks The temporal occurrence and spatial distribution of floods with significant socio-economic effects Bank overflowing capacity of the maximum discharge the upstream contribution to their formation? • Where do they come from? • Where are they going? the upstream - downstream relationship in their propagation? • Which floods should we select for studying? and

MethodologySettingmaximumdischargethresholdStage-dischargerelationshipMagnitude-FrequencyQthreshold ~ 600 m3-s-1foroverflowingtheriverbankrelationship14D0Hmax=f(Qmax)22009 June 2017day of sampling20001200Ditributionofthemaximum14001800Rating curve for 2010discharge regression curve on the1000Uncertainty120016006sya)Jiu River, at Podari g.S.Extreme floods QH rating curve10001400800(.s.wlo800IQ threshold600600800400400H threshold600200200400S2310120002503003504505005501001502004000100Waterlevel-H (cm)Return period (years)

Methodology Return period (years) 10 Ditribution of the maximum discharge regression curve on the Jiu River, at Podari g.s. Setting maximum discharge threshold Magnitude – Frequency relationship Stage – discharge relationship Qthreshold ≈ for overflowing the riverbank 600 m3 ∙s-1