Detection of Snow Depth Trend in the Parts of Namak Lake and Sefidroud Watersheds

Temporal and spatial distribution of snowfall was affected by climate changes. This study was carried out detection of snowfall trend in Namak Lake and Sefidroud watersheds. Trend detection was performed on 27 snow survey stations with sufficient data from 1957 to 2008. In this study, non-parametric Mann – Kendall test was used for assessment of existence and nonexistence trend and also Sen Test was for magnitude of trend. Out of 27 stations, all of which recorded snowfall in January, 12 stations show an increasing trend of snowfall. In February and March, 19 and 23 stations show a decreasing trend of snowfall depth, respectively. Therefore, 12 stations show an increasing trend of snowfall depth in April and Garmabdar and Sierra stations show a decreasing trend in 95% the level of confidence.