Space and time variations of the runoff of Kamchatka Krai rivers

The current features of the space and time variations of river runoff in Kamchatka Krai have been considered. Two relatively long cycles have been shown to exist in water runoff variations in the major portion of the examined rivers. The renewable water resources were increasing until 1970–1980, while in the following years (up to 2010), they were gradually decreasing. Current data on river runoff were used to prove the existence of three zonal types of water regime in Kamchatka Krai; five azonal types of annual runoff distribution are characterized. One of them (nearly uniform annual distribution caused by the predominance of groundwater recharge) has been theoretically predicted in the classification proposed by M.I. L’vovich, though without factual confirmation. The specific features of water regime of rivers whose basins lie on the slopes of active volcanoes are considered for the first time. This type of regime typically shows alternating periods of the presence and absence of surface runoff in river channels, corresponding to the inflow of snowmelt or rainfall runoff at high level of subsoil water (when channel deposits are fully saturated with water) or at its low position (when moisture is deficient).