Kadri YUREKLI, Müberra ERDOĞAN, Saniye DEMİR

Regional Frequency Analysis of 6 hours Maximum Rainfall over the Upper Euphrates–Tigris basins, Turkey

Accurately estimating design rainfall or in other words, probable maximum rainfall has a crucial efficiency on fulfilling the expected benefit from any hydraulic structure since the value predicted as design criteria directly influences its planning, management and cost. What amount of a hydro-climatic variable which takes place under the influence of many environmental factors in a given region would be in future time is estimated based on its statistical behaviour. In many efforts related to water resources, the curve (IDF) representing the relationship among intensity, duration frequency of rainfall is basis for design rainfall amount required in the construction of any water-related structure. The availability of information extracted the curve of IDF substantially depends upon the frequency analysis and reliability of the current data. In this sense, the reliability of the data is very important as well as frequency analysis. The 6 hours maximum rainfall amounts from 18 sites in Upper Euphrates–Tigris basins were used as a material for regional frequency analysis based on L-moments approach. The existence of discordant stations was checked with discordancy measure for whole sites in the study area. First, single homogeneous region was tried to be formed. However, due to the irregularity value of Mardin station being greater than the critical value, no single homogeneous region could be obtained. Clustering analysis method was applied to obtain sub homogeneous regions. According to the dentograms of clustering analysis, the basin was divided into two sub homogeneous regions. Mardin station has been ignored in the study due to its discordant in the sub-regions. The generalized extreme value distribution was selected as the most appropriate regional distribution for the sub-regions.

Keywords:

Euphrates–Tigris basin, Maxima rainfall, L-moments,

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Anlı AS and Öztürk F (2011). Ankara’da Ölçülen Yıllık Maksimum Yağışların Bölgesel Frekans Analizi. Tokat Gaziosmanpaşa Üniversitesi Ziraat Fakültesi Dergisi, 28(1): 61-71.
Anlı AS, Yurekli K, Hınıs MA and Apaydın H (2011). Regional Frequency Analysis for Annual Rainfall Totals of Konya Closed Basin in Turkey. 5th Atmospheric Science Symposium - ATMOS 2011 Proceedings, 27-29 April 2011, 301-312, Istanbul – Turkey.
Eslemian SS and Feizi H (2007). Maximum Monthly Rainfall Analysis Using L-moments for an Arid Region in Isfahan Province, Iran. Journal of Applied Meteorology and Climatology, 46: 494-503.
Greenwood JA, Landwehr JM, Matalas NC and Wallis JR (1979). Probability Weighted Moments: Definition and Relation to Parameters of Several Distributions Expressable in Inverse Form. Water Resources Research, 15: 1049-1054.
Hosking JRM (1994). The four-parameter kappa distribution. IBM Journal of Research and Development, 38: 251-258.
Hosking JRM and Wallis JR (1988). The effect of intersite dependence on regional flood frequency analysis. Water Resources Research, 24: 588-600.
Hosking JRM and Wallis JR (1993). Some Statistics Useful in Regional Frequency Analysis. Water Resources Research, 29: 271-281.
Hosking JRM (1990). L-Moments: Analysis and Estimation of Distributions Using Linear Combinations of Order Statistics. Journal of The Royal Statistical Society Series B, 52: 105-124.
Hosking JRM (1996). Research report: Fortran routines for use with the method of L-moments, Version 3.03. Yorkstown Heights, NY: IBM Research Division: 39 pp.
Hosking JRM and Wallis JR (1997). Regional frequency analysis: An approach based on L-moments. Cambridge University Press, Cambridge, UK. 224 p.
Kysely J, Huth R and Picek J (2005). Regional Analysis of Extreme Precipitation Events in The Czech Republic. Geophysical Research Abstracts, Vol. 7, 01867.
Lettenmaier DP and Potter KW (1985). Testing flood frequency estimation methods using a regional flood generation model. Water Resources Research, 21: 1903-1914.
Okman C (1994). Hydrology. University of Ankara Faculty of Agriculture, Publication No:1388, 359p, Ankara (in Turkish).
Sankarasubramanian A and Sirinivasan K (1999). Investigation and Comparison of Sampling Properties of L-Moments and Conventional Moments. Journal of Hydrology, 218: 13-34.
Yurekli K (2005). Regional Analysis of Montly Rainfalls over Amasya Province via L- moment. Tokat Gaziosmanpaşa Üniversitesi Ziraat Fakültesi Dergisi, 22(2): 51-56.
Yurekli K, Modarres R and Öztürk F (2009). Regional daily maximum rainfall estimation for Cekerek Watershed by L-moments. Meteorological Applications, 16(4): 435-444.

Gaziosmanpaşa Üniversitesi Ziraat Fakültesi Dergisi-Cover

ISSN: 1300-2910
Yayın Aralığı: Yılda 3 Sayı
Başlangıç: 1985
Yayıncı: Tokat Gaziosmanpaşa Üniversitesi Ziraat Fakültesi Dergisi Yayın Ofisi