TurkJAgricFor 26(2002)47-55 ©TÜB‹TAK EstimationofInstantaneousPeakFlowsinSeyhanRiverBasin UsingRegionalRegressionProcedures FatihTOPALO⁄LU UniversityofÇukurova,FacultyofAgriculture,AgriculturalStructuresandIrrigationDept.,01330Yüre¤ir,Adana-TURKEY Received:04.12.2000 Abstract: MultivariateproceduresforestimatinginstantaneousfloodflowsforvariousreturnperiodsinSeyhanriverbasinare presentedinthestudy.Proceduresaimatdevelopingregressionequationsuscableforthebasinusingannualpeakinstantaneous flows,climaticandmorphometriccharactcristics.Itwasdeterminedthatbestsubsetanalysisgavethehighestdetermination coefficients(91.0%<R2<95.0%)thanstepwiseanalysis(84.23%<R 2<85.13%),principalcomponentanalysisandfactoranalysis (69.2%<R2<71.0%).Climaticcharacteristic,basinarea,andstreamfrequencyarethemostimportantcharacteristicsindeveloped equationsforthebestsubsetanalysis.Inaddition,thefloodflowestimationcapabilityofthebestsubsetequationsforthe Seyhan riverbasinisdemonstratedtobesufficientusingstatisticalcritcrionofpredictionerror.Floodestimatesforagivenretur nperiod canbedoneusingthebestsubsetequationsofonlythreecharacteristicsatanungaugedsiteintheSeyhanriverbasinwithout measuringanyflowdata. KeyWords:InstantaneousFlows,Flood,ClimaticandMorphometricCharacteristics,BestSubsetAnalysis,MultivariateAnalyses, RegionalRegressionEquations SeyhanHavzas›Akarsular›ndaBölgeselRegresyonYöntemleriileAnl›k MaksimumAk›mTahmini Özet: Çal›flmadaSeyhanhavzas›içinfarkl›yinelenmey›llar›naaitanl›kmaksimumak›mlar›tahminetmedekullan›labilecekçok de¤iflkenliyöntemlersunulmufltur.Buyöntemlery›ll›kmaksimumanl›kak›mlar›,iklimvemorfometrikkarakteristiklerikullanara k havzaiçingeçerliregresyoneflitlikleriningelifltirilmesiniamaçlamaktad›r.Enyüksekbelirlemekatsay›s›n›neniyialtgrupanalizinden eldeedildi¤i(%91.0<R 2<%95.0)ves›ral›çokluregresyonanalizinde(84.23%<R 2<85.13%),anabileflkeleranalizivefaktör analizindeise(69.2%<R2<71.0%)bukatsay›n›ndahadüflükoldu¤ubelirlenmifltir.Eniyialtgrupanalizindegelifltirilendenklemlerde iklimkarakteristi¤i,havzaalan›vederefrekans›n›nenönemlikarakteristikleroldu¤usaptanm›flt›r.Ayr›ca,eniyialtgruptaeldeedilen denklemlerinhatatestiistatistikselkriterisonucundataflk›nlar›tahminetmedeyeterlioldu¤ugörülmüfltür.Seyhannehirhavza s›nda ölçümüolmayanbiristasyondaherhangibirak›mverisiölçmeksizinistenenbiryinelenmey›l›içintaflk›ntahminlerisadeceüç karakteristiklieniyialtgrupdenklemlerikullan›larakyap›labilir. AnahtarSözcükler: Anl›kAk›m,Taflk›n,Havzave‹klimKarakteristikleri,En‹yiAltGrupRegresyonAnalizi,ÇokDe¤iflkenliAnalizler, BölgeselRegresyonEflitlikleri Introduction interest,regionalstudies,suchasregionalregression Estimatesoffuturefloodmagnitudesofagiven analysis,usingmorphometricandclimaticcharacteristics returnperiodinareaswherenoflowgaugingstations ofthebasin,canbeusefulforestimatingthefloodflows. existorwheregaugerecordsareveryshortarerequired Manyresearchershavedevelopedregionalregression fortheeconomicalplanninganddesignofriverbasin equationsforestimatingthefloodflowsofvariousreturn projects(Dalrymple,1960).However,themethodof periodsusingflowsandtheclimaticandmorphometric estimationemployeddependsuponthequantityand characteristicsandhavefoundthatdifferent qualityoftheavailabledataandthenatureandeconomic characteristicsaffectfloods(Bilgin,1981;Acreman, lifeoftheproject(Tülücü,1996). 1985;Horn,1988;DriverandTroutman,1989; MimikouandGordios,1989;GardeandKothyari,1990; Floodrecordsoveralongperiodarenotavailablefor Pitlick,1994). manycatchmentsinTurkey.Basedonlimiteddata, investigationsprovidingfloodestimationequationsmay Inthispaper,anattemptismadetodevelopregional produceresultswithlargeerrors.Therefore,incases floodpredictionequations,whichtakeasinputsthe wherelimitedrecordsareavailableatornearthesiteof morphometricandclimatologicalcharacteristicsofthe 47 EstimationofInstantaneousPeakFlowsinSeyhanRiverBasinUsingRegionalRegressionProcedures basin,forvariousreturnperiodsintheSeyhanriver distributionssuchasGumbel,Log-Logistic,Pearson-3, basin. Log-Pearson-3andLog-Normal-3distributionswere selected.Theparametersofthedistributionswere estimatedbythemethodsofmoments(MOM)andthe Materials probabilityweightedmoments(PWM),excepttheLog- FloodFlowData Normal-3. Theannualinstantaneousfloodpeaksandtheannual Intheanalysis,theGringortenplottingposition peakdailyprecipitationseriesvaryingfrom15to56and formulawasusedforexaminingthedistributions.In 14to67yearswerepickedfor13runoffgauging(RS) addition,adetailedchi-squaredgoodness-of-fittestwas and55precipitationgauging(PS)stationsoftheSeyhan performedbothwithequal-lengthslicedhistogramsand riverbasin,respectively.Flowandprecipitationdatawere withequal-probability-areaslicedhistogramsbeing takenfromthepublicationsofDS‹(1990and1994)and repeatedthreetimesforthreedifferentbutconsecutively Topalo¤lu(1999).Flowdataareallfreefromregulation increasingslicenumbers(Haktan›r,1991).Many byanysizeablestructure.DetailsofallRSsandPSsare referencesarealsoavailableabouttheprobability giveninTables1and2,respectively. distributionsandtheirparameterestimationmethods MapData (Haktan›r,1991and1992). Therearedifferentscaledmapssuchas1:5,000, DevelopmentofDatabaseonClimaticand 1:25,000,1:100,000and1:250,000fortheSeyhan MorphometricCharacteristics riverbasin.However,1:100,000scaledmapsprovided Theclimaticandmorphometriccharacteristicsmost bytheUniversityofÇukurova,FacultyofEngineeringand oftenusedtopredictfloodpeaknumbersareabouta Architecture,DepartmentofGeologicalEngineeringwere dozen(Thiessen,1911;Horton,1932;Strahler,1964; used,takingthetimeofworkingintoconsideration. Acreman,1985).Theselectedclimaticandmorphometric characteristicswhichhavebeenwidelyusedinthe developmentofregionalmodelsarethefollowing:annual Methods peakdailymeanarealprecipitationP T;basinareaA B (the FrequencyAnalysis totalareaprojecteduponahorizontalplane,contributing Frequencyanalysiswasperformedforeachgauged overlandflowtothechannelsegment);streamlengthL sitebyemployingacomputersoftwarepackage (thelengthofprincipalstream);Benson’sslopeBS(the (Haktan›r,1991).Intheanalysis,themostcommon slopebetweentwopointsalongthemainchannel Table1. Somecharacteristicsoftheselectedrunoffgaugingstations Gauge Nameof Yearsof Elevation Ave.Runoff Coef.of GumbelParameters Numbers River Record (m) (m3s-1) Variation Scale Location 1801 GoksuRiver 1936-91 665 198.38 0.61 0.00756 144.530 1802 ZamantiR. 1936-54 858 90.04 0.33 0.03571 75.598 1804 ZamantiR. 1941-55 1345 43.00 0.47 0.05063 33.003 1805 GoksuR. 1940-91 350 629.54 0.55 0.00335 462.680 1806 ZamantiR. 1961-79 347 325.47 0.67 0.00481 216.970 1812 ZamantiR. 1955-73 1425 40.17 0.40 0.06632 32.344 1817 CakitC. 1964-85 150 94.69 0.46 0.02470 73.434 1818 SeyhanR. 1966-91 180 1175.90 0.51 0.00184 886.350 1820 KorkunC. 1970-91 170 154.59 0.72 0.00736 101.520 1821 EglenceC. 1971-86 75 261.44 0.50 0.00784 195.710 1822 ZamantiR. 1970-91 1270 80.67 0.37 0.03570 65.927 1823 ZamantiR. 1974-90 1451 48.65 0.61 0.03490 33.873 18-12 KorkunC. 1971-90 1109 51.03 0.60 0.03450 35.877 48 F.TOPALO⁄LU Table2. SomepropertiesofPSswithinandnearbytheSeyhanriverbasin NameofGauge Yearsof NumberofPeaks Elevation Ave.Prec. Coef.of GumbelParameters Site Record Used (m) (mm) Variation Scale Location Adana 1929-95 67 20 70.09 0.40 -0.04200 56.888 Afsin 1954-83 30 1180 32.54 0.23 0.15080 28.985 Akkisla 1964-87 24 1500 28.60 0.26 0.14410 24.920 Andirin 1953-83 31 1250 102.21 0.34 0.03170 85.273 Bakirdag 1960-81 22 1300 27.02 0.39 0.10170 21.841 Bor 1964-83 20 1100 22.62 0.38 0.12470 18.417 Bunyan 1957-87 31 1300 29.10 0.35 0.10970 24.210 Camardi 1969-82 14 1500 32.06 0.30 0.10330 27.126 Camliyayla 1967-86 20 628 82.82 0.28 0.04590 71.424 Cardak 1967-84 18 1175 46.59 0.39 0.05810 37.649 Catalan 1964-86 23 65 73.60 0.30 -0.04900 62.810 Ceyhan 1942-95 54 30 67.40 0.42 0.04120 54.038 Ciftehan 1967-82 16 1000 78.38 0.45 0.02890 60.562 Cokak 1969-87 19 1350 111.89 0.54 0.01740 81.962 Develi 1951-95 45 1180 28.06 0.34 0.11920 23.479 Dogankent 1968-87 20 20 76.97 0.43 0.03200 60.620 Elbasi 1965-87 23 1425 25.61 0.29 0.19410 20.867 Feke 1942-93 52 620 75.82 0.30 0.13270 69.383 Gemerek 1957-95 39 1173 27.37 0.27 0.15350 23.833 Gezi 1965-87 23 1250 28.79 0.37 0.10060 23.539 Goksun 1954-91 38 1344 45.35 0.30 0.08254 38.776 Gulek 1957-78 22 950 84.33 0.42 0.03065 67.143 Hacilar 1964-84 21 1500 34.92 0.28 0.10853 30.080 Hacialiciftl. 1963-79 17 12 69.63 0.46 0.03282 53.854 Imamoglu 1963-86 24 100 64.56 0.34 0.04901 53.753 Kadirli 1956-87 32 100 61.89 0.28 0.06433 53.528 Kamisli 1963-87 25 1225 66.37 0.60 0.06850 45.535 Karaisali 1957-95 39 400 99.60 0.42 0.02708 79.548 Karatas 1963-88 26 5 76.61 0.37 0.03825 62.696 Karsanti 1960-75 16 860 88.19 0.31 0.03320 28.920 Kaynar 1964-82 19 1550 27.63 0.34 0.11234 22.982 Konakli 1966-81 16 1265 29.24 0.27 0.12964 25.268 Kozan 1951-95 45 150 72.06 0.36 0.04436 59.744 Mansurlu 1964-85 22 1050 68.36 0.34 0.04669 57.077 Nigde 1935-95 61 1208 26.22 0.36 0.12286 21.727 Orensehir 1964-87 24 1600 28.61 0.32 0.11992 24.196 Pazaroren 1964-87 24 1500 29.73 0.35 0.10335 24.609 Pinarbasi 1950-95 46 1470 27.62 0.30 0.14080 23.734 Pozanti 1960-86 27 778 76.99 0.43 0.03342 61.034 Saimbeyli 1957-87 31 1100 65.49 0.38 0.04525 53.619 Sarioglan 1964-87 24 1150 31.38 0.25 0.13611 27.488 Sariz 1951-87 37 1500 34.32 0.40 0.08275 27.775 Sarkisla 1939-87 49 1180 26.63 0.34 0.12637 22.289 Talas 1970-86 17 1100 27.89 0.31 0.11845 23.524 Tanir 1968-88 21 1200 35.32 0.61 0.04931 24.672 Tarsus 1941-62 22 33 60.69 0.28 0.06275 52.291 Toklar 1965-83 19 1400 31.18 0.48 0.07053 23.782 Tomarza 1963-88 26 1400 29.10 0.37 0.10207 23.887 Tufanbeyli 1957-73 17 1350 36.94 0.38 0.07450 29.992