Abstract
In recent years, climatic changes have had a greater impact on the hydrological cycle, leading to continuous changes in climate on both temporal and spatial scales. Therefore, this study aimed to verify the credibility and homogeneity of the data, so when conducting any study in the field of climate and hydrological change, the homogeneity of the data used must be tested. In the current study, eight climatic stations distributed in Nineveh Governorate were selected, using climatic data represented by (rainfall, maximum and minimum temperatures, and maximum and minimum humidity) for the time period 1990-2020. Four statistical methods were used, namely, Von Neumann test (VONT), Standard Normal Homogeneity test (SNHT), Buishand test (BRT) and the Pettitt test at a significance level of 5%. The results showed that the monthly rainfall was homogeneous for all stations except for three months (2, 2, 11) for the stations of Tal-Abta, Ba’aj, and Al-Sheikhan. As for the temperature and humidity, they were heterogeneous for most of the stations, as the percentages for months that were heterogeneous in temperature reached 35% and 42% for the maximum and minimum, respectively. As for the humidity, the percentage of the heterogeneous months were 18% and 14% for the maximum and minimum, respectively. The study showed that the SNHT and VON tests are the most sensitive to the breakpoint and the Pettitt test is the least sensitive in most tests. The heterogeneous climatic data were also corrected by using the double mass curve method and converted into homogeneous climatic data.
