Physical Factors Determining Runoff Coefficient in the Watersheds of Ardabil Province

Runoff coefficient can be used as a measure for assessing the flood generation potential of the watersheds. This factor is depending on the watershed characteristics and may vary temporally during a year. Knowledge on the watersheds with higher potential to runoff production and determining pick time of runoffs is essential for designing watershed management practices in an area. In this study, physical characteristics with rainfall and runoff data for a thirty-year period (1986-2010) were studied in eleven forth order watersheds in Ardabil, Iran. The watersheds surface areas vary from 257 to 2184 km2 and their slopes are between 16.25% and 33.3%. Significant differences were found among their monthly rainfall (p