Spatio-temporal trend and change detection of temperature and precipitation of Kashafroud basin

The study of meteorological characteristics and its variability is important in assessing the climate change impacts for water resources management. Trend analysis of hydrological and meteorological time series is a method for determining the change in climate variables that is performed with different parametric and non-parametric methods. In this research, the annual, seasonal and monthly trends were analyzed regarding rainfall and temperature time series for 1986-2017 in 28 stations of Kashafroud basin in the Northeast of Iran. For this purpose, the annual, seasonal and monthly trends were evaluated using non-parametric Mann Kendall and Pettitt test at 95% level significance. The results showed the trend for the monthly maximum temperature in spring and winter and also the annual trend for all stations was increasing, whereas the summer and autumn pattern differed. The trend of minimum temperature in all seasons and stations do not have a uniform pattern. The results of precipitation trend indicated that the annual precipitation of the basin had not changed and did not have a significant trend in 5% level of significance. Precipitation of the basin in the winter decreased. There was an increasing trend in the Southern half of the basin in autumn. The noticeable decrease of precipitation in winter season especially during January and February with an increase in November can be a serious challenge for water resource management of basin during the dry season.