Changes and trends in Precipitation the example of Sinop Hopa (Black Sea) coastal zone in Turkey

Abstract

The study area covers the area in the middle and east part of the Black Sea coastal zone. This area includes thecentral and eastern black sea districts. In particular, the Eastern Black Sea district is the only area that is close to theoceanic climate in Turkey. In this area, precipitation is distributed equally throughout the year. Sinop, Samsun, Ordu,Giresun, Trabzon, and Rize are important settlements in the region. In this study, precipitation data provided by theTurkish State Meteorological Service. It has been tested whether the long-term annual total precipitation data arehomogeneous or not. For this purpose, Pettitt’s, SNHT, Buishand’s tests were applied. Long-term changes and trendsin the data were analyzed using the Mann-Kendall test.Change points in precipitation data determined the 1980s and early 1990s. For long-term changes in precipitation,the early 1980s can be considered as the beginning of significant change. Especially in the last 20 years, veryimportant changes have been experienced in the precipitation. There is an increasing tendency in more than 80% ofthe stations in total annual precipitation. The humid and dry periods are quite evident and long-term at all stations.The 1970s to the mid-1980s experienced less than average precipitation. After the 1980s, the effects of the humidperiod in which long-term rainfalls above average were observed. According to the Mann-Kendall test, the beginningof trends at some stations in the late 1980s and early 2000s. Since these change points, significant changes haveoccurred in precipitation data. Increases in total annual precipitation are also statistically significant.