REGIONALIZATION AND MAPPING OF DISSOLVED OXYGEN CONCENTRATION OF SAKARYA BASIN BY L?MOMENTS METHOD

Abstract

In this study, a regionalization study was conducted with the L–Moments method in order to determine the change of dissolved oxygen (DO) required to sustain the life of aquatic organisms in a given return period and also to consider the effects of all stations. Dissolved oxygen concentration data of 20 meteorological stations for spring months were evaluated between 1995 and 2014 in Sakarya Basin, Turkey. Firstly, Homogeneity Criterion (H1) statistical results have been determined that the study area is not uniformly homogeneous in Sakarya Basin (H1= 18.01 >> 1.0). In order to implement the L?Moments method, the Sakarya Basin is divided into five homogeneous regions considering the topographic characteristics of the basin. In the second phase of the study, L?Moments method; Wakeby distribution proposed by Hosking parameters were estimated. By using the parameter values of the Wakeby distribution, statistical dimensionless DO content values corresponding to the periodic repetition periodswere obtained. In the last stage of the study; 50, 100, 200, 500 and 1000 years repetitive thematic DO content maps were created by using Inverse distance weighted interpolation method (IDW) with the aim of visually expressing DO content data estimated by L?Moments method.