Trend Analysis of Monthly Average Flows of Kizilirmak Basin

Abstract

The impact of climate change on meteorological data and water resources is one of the subjects of interest in both hydrology and meteorology. The change in meteorological occurrences due to the atmospheric circulation of climate is an important factor in the design of water structures and water management issues. In this study, trend analysis was performed by using monthly average current values taken from three different current observation stations in Kizilirmak basin and the presence of meaningful trend was investigated. Mann Kendall (MK) and Modified Mann Kendall (Hamed) and Spearman's Rho (SRHO) methods are the non-parametric methods used in trend analysis of basin flows. The linear regression method, which is a parametric method, is also included in the study of trend. Pettit method was used to determine the beginning of the trend. The mean monthly flow data between the years of 1970 and 2010 were taken from 15-03, 15-68 and 15-208 stations analyzed and as a result an increasing trend in 15-68 stations and a decreasing trend was determined in 15-208 and 15-03 stations. According to the Pettit test, the beginning of the increase trend in flow at station 15-68 is September 1986. And the beginning of the decrease in the 15-208 station was in April 1989 and the beginning of the decrease in the 15-03 stations took place in 1999-September.