Document Type : Research Paper

Authors

• Hossein Negaresh ¹
• Behrooz Sarisaraf ²
• Mohammad Daraee ³

¹ Geography and Environmental Planning, University of Sistan and Baluchestan

² Department of Geography, tabriz University

³ Climatology in Environmental Planning, University of Tabriz

Abstract

In this study at first, we supposed the normality of the data by some statistical parametric methods and then using non-parametric (Mann-Kendall) test, the non-linear trend of basin precipitation changes from a period of 45 years (1961-2005) relating to the synoptic station of Saqqez have been investigated. The statistical test results were: 1-The decreasing trend of spring precipitation is significant. 2-There is a significant increasing in summer precipitation. 3-The numerously at precipitation days at the thresholds 1 to 20mm has been decreased, but it increased at the large thresholds to 25mm. 4-The frequency trend of rainstorms days has the significant increasing.

Keywords

• Precipitation Changes
• Mann-Kendall
• Non-linear trend
• Precipitation days
• Saqqez