Homogeneity Analysis of Precipitation Series in North Iraq

Abstract

Reliability and quality of historical precipitation data are subjected to keen evaluation before a study in water resources, hydrological processes, and climate change fields. In this context, homogeneity tests emerge as a useful tool to control the data reliability and quality. In this study, the homogeneity of the annual and seasonal precipitation data throughout the north of Iraq was investigated using the Pettit, Standard Normal Homogeneity (SNH), Buishand (BR), and Von Neumann (VNR) tests at a significance level of 0.05. Long-term precipitation records taken from nine meteorological stations, were analyzed by each of the four homogeneity tests. Based on annual data, the results of the SNHT test indicated the four stations as inhomogeneous. Moreover, Pettit test exhibited inhomogeneous results for Mosul and Derbandghan stations. The spring precipitation data for all stations were classified as useful except for the Dokan station which was classified as doubtful for the spring precipitation data. As a result, it was concluded that 2, 3, and 1 out of 9 stations were assessed as doubtful for annual, winter, and spring precipitation data, respectively.