Suitability of two-parameter gamma and three-parameter beta distributions as synthetic unit hydrographs in Anatolia

Abstract

The scale-adjusted probaMity density functions of the two-parameter gamma and the three-parameter beta distributions were shown to fit reasonably well to ten observed unit hydrographs in Anatolia, the gamma exhibiting slightly better fits. As a result, a method making use of this curve is suggested for the synthetic unit hydrograph. Bons résultats obtenus avec les distributions gamma à deux paramètres et béta à trois paramètres pour la génération dTrydrogrammes unitaires synthétiques en Anatolie Résumé Le fonction de densité de probabilité gamma à deux paramètres et la fonction béta à trois paramètres sont avérés bien adaptés à dix hydrogrammes unitaires en Anatolie; la fonction gamma s'adapte mieux aux hydrogrammes. En conséquence on propose un méthode utilisant cette courbe pour les hydrogrammes unitaires synthétiques.

Synthetic Unit Hydrograph Methods: A Critical Review

“…Use of probability distribution functions as SUH has a long history [18][19][20][21][22]. More recently, the potential of four popular pdfs, i.e.…”

“…However, the empirical relationships (Eqs. [19][20][21][22] are watershed size specific, and should be used with in the area limits for which these are developed [1,12]. .…”

“…Due to similarity in the shape of the statistical distributions and a conventional unit hydrograph, several attempts have been made in the past to use their probability distribution function (pdfs) for derivation of the SUH [17][18][19][20][21][22]. Based on the concept of n linear reservoirs in series, Nash and Dooge [23,24] independently developed the general equation of the IUH in the form of two-parameter gamma distribution function (2PGDF).…”

A variable storage coefficient model for rainfall—runoff computation / Modèle pluie—débit basé sur un coefficient de stockage variable

“…For comparison, the 2-hour UH is taken directly from Haktanir & Sezen (1990). The estimated values of parameters of the 2VSC IUH and 2PGD IUH models are found to be K = 2.70 h, r = 1.46; and K = 1.32 h, n = 5.53, respectively.…”

“…The 2VSC IUH (equation (20)) and the 2PGD IUH (equation (32)) models were applied to the published data of Gormel Ermenek Creek catchment (142 km 2 ) located in Anatolia, Turkey (Haktanir & Sezen, 1990). For comparison, the 2-hour UH is taken directly from Haktanir & Sezen (1990).…”