Hillslope Hydrology Flashcards
Name 5 factors which affect hillslope hydrology.
Precipitation. Seasonal changes. Agricultural practices. Deforestation. Relief.
What is the soil water balance?
It shows the state of equilibrium between inputs and outputs.
How to calculate the water balance.
p = Q+E +/- change in store.
p - Precipitation
Q - Run off
E - Evapotranspiration.
What is a positive water balance?
Occurs when precipitation exceeds evaportranspiraion loss.
What is a a negative water balance?
Occurs when evapotranspiration exceeds precipitation.
What is a soil moisture budget?
Amount of water in soil.
What is soil moisture surplus?
When precipitation exceeds evapotranspiration, leading t a greater surface runoff - winter.
What is soil moisture deficit?
When evapotranspiration exceeds precipitation, leading to a drop in water levels - summer.
What is recharge?
Occurs in autum when first surplus of water is used to recharge the soil until soil reaches field capacity.
When is field capacity reached?
When the excess water has been drained away.
Regarding the water budget graph.
What happens in winter?
Precipitation exceeds evaporation and soil moisture us recharged until there is a soil moisture or water surplus.
(temp isn’t too high)
Regarding the water budget graph.
What happens in summer?
Evaporation exceeds precipitation, soil becomes utilised.
Second half of summer there is a soil moisture deficit.
(temp increases)
Regarding the water budget graph.
What happens in the autumn?
Precipitation increased and evapotranspiration falls allowing soil moisture to be recharged once more.
(temp fall)