Annual distribution of river runoff with estimated contribution of winter low-water season

Proportions of the overland, delayed, and groundwater runoff are given for different phases of the hydrological regimes of rivers under different landscape–climate conditions in Russia. The concept of runoff hydrological regime is in agreement with the formation features of the annual and seasonal runoff on small watersheds under current climate conditions. The increase in winter runoff is due to the impulse discharge regime of soil water and groundwater, which receive additional recharge during frequent thaws and at weak freezing of the aeration zone. Variations in the values of runoff, total precipitation, and mean temperature were shown to be both synchronous and periodic.