Document Type : scientific-research article

Authors

• Saeed Jahanbakhsh Asl
• Ma’soumeh Tadayoni
• Habibeh Nouri Oghourabad

Abstract

The aim of this research is the study of trends in annual precipitation changes in some selected stations located in the Sefid Rood basin, applying the Man-Kendall non-parametric technique. The method is one of the most frequently used non-parametric techniques for trend analysis of precipitation on an annual scale. Six synoptic stations located in the Sefid Rood basin were selected for the analysis containing data records for a 30-year period (1978-2007). The results of the analysis indicated a significant trend in the precipitation of Khalkhal and Birjand stations, while there was no significant trend in Rasht and Zanjan stations with 95% and 99% confidence levels. At a 95% significance level, there was an ascending and significant trend in Lahijan station, whereas this trend was descending and significant in Mianeh station.

Keywords

• Trend analysis
• Precipitation
• Man-Kendall Test
• the Sefid Rood Basin