روشهاي برآورد جريان حداكثر لحظه اي سيل در حوزه هاي شمال كشور

Maximum instantaneous flood flow in the countriʹs north basins

Some relations for flood design estimating in sub-catchments in east and West part of north basin (Khazer basin) are established using multiple regression and index flood method. There are 31 sub-catchments in east part and 22 in west part of this area as gauged catchments. Factor analysis approach has realized that amongst several factors affecting on instantneous peak discharge, area of watershed, length of main channel, mean slope of watershed, mean annual precipitation, drainage density and compactness coefficient harv the largest effects, thus they are used in regional flood estimation analysis. Four homogenous groups of catchments are classified for each part of whole area and also entire area as one group using cluster analysis, Anderw curves and discrimination test. Some relations have been established for each of these groups and also for entire area of both part of Khazer basin using flood index method as well as multiple regression analysis. The results are successful in comparison with previous works have been done by others in this area.