how does snow and snow melt water affect runoff

Snow and snowmelt water affect runoff of situated in cold environments. there are 3 modes of snow melt runoff generation, they are as below:-

a)Melting runoff infiltrates the into the unsaturated soil and flows towards the stream as thoroughflow ( or penetrates to the ground water);

b)When the surface is impermeable and the melt water  runs along the base of the snow pack downslope to the stream. The surface may be impermeable because it is bed rock or because the soil is frozen. Soil frost depth depends on the depth of snow cover(thick snow acts as an insulator).the effect of soil freezing on the rate of snow melt runoff is unclear. many other factors low rate of snow melt ,relative amount of rainfall and snowmelt and the amount of snow under the different vegetation types have a greater effect on the volume of runoff.

c)When the water table rises to the surface within the snow pack, Resulting in saturation excess overland flow occurring at the base of the snow pack. the areal extent of this saturated zone  will of course vary through the period of snow melt and the area constituting rapid runoff will increase when melting continues.

                 Snow melt is often driven by energy inputs and often enhanced by rainfall and there are 3 phases of this :-

a)Warming phase;

b)Ripening phase;&

c)Output phase.

there are 5 potential sources of energy for snow melt are:-

a)net radiation;

b)sensible heat transfer from the warm air to the snow;

c)latent heat released by condensation of moisture onto the snow pack;

d)heat received from the ground;&

e)heat released as rain water falling on the snow pack cools.