Neslihan SEÇKİN, Smaeel DODANGEH, M. Taghi SATTARİ

Minimum akımların L-momentler yöntemi ile bölgesel frekans analizi

Bu arastırmada İran'ın kuzey bölgesindeki Sefidrud barajı havzasında yer alan 41 akım ölçüm istasyonunun 26 tanesine ait veriler dikkate alınarak bölgesel frekans analizi saptanması amaçlanmıstır. Hidrolojik kuraklık indisi olarak 7 günlük düsük akımlar incelemeye alınmıstır. Fortran dilinde yazılan bir bilgisayar programı yardımı ile hesaplanan heterojenlik ölçüsü (H) istatistiğine göre çalısma alanının homojen olmadığı tespit edilmistir (H1=13.68). Havzanın fizyografik ve hidrolojik özelliklerine dayalı bulanık grup analizi (Fuzzy Cluster Analysis) yöntemi ile havza doğu ve batı olarak iki bölgeye ayrılmıstır. L-momentler analizi sonuçlarına göre doğu bölgesi homojen bulunmus, batı bölgesi ise Gilvan, Yengikend ve Firuzabad istasyonları göz ardı edilerek homojen olması sağlanmıstır. Z uygunluk ölçüsü istatistiği sonuçlarına göre Genellestirilmis Lojistik (GLOG) ve Pearson Tip 3 (PE3) dağılımları sırasıyla doğu ve batı alt bölgeleri için en uygun dağılımlar olarak seçilmistir. Sonuç olarak seçilen uygun dağılımların Sefidrud havzası bölgesel düsük akımlarının tahmininde kullanılmaları önerilmistir.

Regional frequency analysis of minimum flow by L-moments method

In this study, it was aimed to determine regional frequency analysis for selected 26 stations out of 41 streamflow gauging stations located in Sefidrud Dam watershed in north of Iran.7-day low flows are considered as indices for hydrological drought analysis. The study area was identified as heterogeneous based on the homogeneity measurement (H1=13.68) by a software with code written in FORTRAN language. Therefore Fuzzy Cluster Analysis (FCA) algorithm is applied to distinguish the homogeneous sub regions by taking into consideration the physiographic and hydrologic characteristics of the watershed. Two regions were identified as the result of FCA analysis namely; east region and west region. According to the L-Moment analysis, East region of the watershed was found homogeneous and the West region of the watershed became homogeneous after removing the Gilvan, Yengikend and Firuzabad streamflow stations. The Generalized Logistic (GLO) and Pearson Type III (PIII) distributions were selected as the best fit regional distributions for the east and west sub-regions, respectively. The best fit distribution is selected with the smallest absolute value of the Z statistic (ZDIST) based on the goodness-of-fit-test. The selected best fit distributions are advised to use in the regional low-flow forecasting of Sefidrud watershed.

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Anlı A S, Apaydın H & Öztürk F (2007). Regional flood frequency estimation for the Göksu river basin through L-moments. International River Basin Management Conference, State Hydraulic Works, 22- 24 March, Gloria Golf Resort Hotel, Belek, Antalya, pp 424-438
Anlı A S, Apaydın H & Öztürk F (2009). Trabzon ilinde gözlenen yıllık maksimum yağısların bölgesel frekans analizi. Tarım Bilimleri Dergisi 15(3): 240- 248
Bezdek J C (1981). Pattern Recognition with Fuzzy Objective Function Algorithms Plenum Press, New York
Chen Y D, Huang G, Shao Q & Xu C Y (2006). Regional analysis of low flow using L-moments for Dongjiang basin, South China. Hydrological Sciences Journal 51(6): 1051-1064
Chowdhury J U & Stedinger J R (1991). Confidence interval for design flood with estimated skew coefficient. Journal of Hydraulic Engineering 117(7): 811–931
Durrans S R & Tomic S (1996). Regionalization of lowflow frequency estimations: an Alabama case study. Water Resources Bulletin 32(1): 23-37
Eratakulan S J (1970). Probability distribution of annual droughts. Journal of Irrigation and Drainage Engineering 96: 461-474
Gebeyehu A (1989). Regional Flood Frequency Analysis. Hydraulics Laboratory,The Royal Institute of Technology, Stockholm. Bulletin No.TRITA-AVI- 148
Greenwood J A, Landwahr J M, Matalas N C & Wallis J R (1979). Probability weighted moments: definition and relation to parameters of several distributions expressible in inverse form. Water Resources Research 15(5): 1049-1054
Hall M J & Minns A W (1999). The classification of hydrologically homogeneous regions. Hydrological Sciences Journal 44(5): 693-704
Hosking J R M & Wallis J R (1993). Some statistics useful in regional flood frequency analysis. Water Resources Research 23:271-281
Hosking J R M (1990). L-moments: analyzing and estimation of distributions using linear combinations of order statistics. Journal of Royal Statistical Society B 52:105-124
Hosking J R M & Wallis J R (1997). Regional frequency analysis: an approach based on L-Moments. Cambridge University Press, Cambridge
Jingyi Z & Hall M J (2004). Regional flood frequency analysis for the Gan-Ming River basin in China. Journal of Hydrology 296: 98-117
Kil S L & Sang U K (2008). Identification of uncertainty in low flow frequency analysis using Bayesian MCMC method. Hydrological Processes 22(12): 1949-1964
Kroll C K & Vogel R M (2002). Probability distribution of low streamflow series in the United States. Journal of Hydrological Engineering 7(2): 137-146
Lim Y H & Lye L M (2003). Regional flood estimation for ungauged basins in Sarawak, Malaysia. Hydrological Sciences Journal 48(1): 79-94
Matalas N C (1963). Probability distribution of low flows. Professional Paper 434-A:27p, U.S. Geological Survey, Washington, D.C
Modarres R (2008). Regional frequency distribution type of low flow in North of Iran by L-moments. Water Resources Management 22(7): 823-841
Önöz B & Bayazıt M (1999). GEV-PWM model for distribution of minimum flows. Journal of Hydrologic Engineering 4(3):289-292
Parida B P, Kachroo R K & Shrestha D B (1998). Regional flood frequency analysis of Mahi-Sabarmati Basin (Subzone 3-a) using index flood procedure with L-moments. Water Resources Management 12: 1-12
Peng S, Xi C, Si-min Q, Zhi-cai Z & Jian-liang M (2010). Regional frequency analysis of low flow based on L moments: Case study in Karst area, Southwest China. Journal of Hydrologic Engineering 15(5): 370-377
Pilon P J & Adamowski K (1992). The value of regional information to flood frequency analysis using the method of L-moments. Canadian Journal of Civil Engineering 19: 137-147
Rao, A R & Hamed K H (2000). Flood Frequency Analysis. CRC Press, Boca Raton, FL Saf B (2009a). Batı Akdeniz havzalarının L-momentlere dayalı bölgesel taskın frekans analizi. Pamukkale Üniversitesi Mühendislik Bilimleri Dergisi 15(2): 153-165
Saf B (2009b). Regional flood frequency analysis using L-Moments for the West Mediterranean Region of Turkey. Water Resources Management 23: 531-551
Seçkin N (2009). L-momentlere Dayalı Gösterge-Sel Metodu ile Bölgesel Taskın Frekans Analizi, Doktora tezi, Çukurova Üniversitesi Fen Bilimleri Enstitüsü (Basılmamıs), Adana
Seçkin N, Yurtal R, Haktanır T & Topaloğlu F (2010). Regional Flood Frequency Analysis of Ceyhan River Basin in Turkey using L-moments Method. Fresenius Environmental Bulletin 19(11a): 2616-2624
Sorman A Ü (2004). Bölgesel frekans analizindeki son gelismeler ve Batı Karadenizde bir uygulama. Đnsaat Mühendisleri Odası Teknik Dergi 15(2): 3155-3169
Smakhtin V U (2001). Low flow hydrology: a review. Journal of Hydrology 240(3-4): 147-186
Vogel R M & Fennessey N M (1993). L-moment diagram should replace product moment diagram. Water Resources Research 29(6): 1745–1752
Vogel R M, McMahon T A, Chiew F H H (1993). Flood flow frequency model selection in Ausralia. Journal of Hydrology 146:421–449
Yürekli K & Simsek H (2002). Frequency analysis for Kelkit Stream’s the daily extreme flows. Tarım Bilimleri Dergisi 8(3): 256-260
Yürekli K, Kurunç A & Gül S (2005). Frequency analysis of low flow series from Çekerek stream basin. Tarım Bilimleri Dergisi 11(1): 72-77