Variability and Trends in the Duration and Depth of Snow Cover in Iran in Thirty Years

This study investigates the changes and variability of the number of days with snow cover of ≥ 1 cm depth and the seasonal maximum snow cover depth at 28 meteorological stations throughout Iran, spanning a period of 30 (1981-82 to 2010-2011) to 15 (1996-97 to 2010-2011) Winter seasons. Investigation of spatial variability of parameters using GIS map shows that maximum of the snow depth and the number of days with snow cover belongs to Koohrang station in Zagros mountains about 69.4 cm and 2457 days in 15 winter season, respectively. A decreasing trend of snow cover in the 30 winter seasons is observed in areas with abundant snow cover in highland stations. However, the scale of the snow cover change is not proportional to the air temperature changes in the most stations.