The water balance. Flashcards
What does the water balance show?
The balance between water inputs and outputs in a drainage basin. The water balance affects how much water is stored in the basin. Where the general water balance of the UK shows seasonal patterns.
How is the water balance worked out?
Precipitation = Total runoff + Evapotranspiration +/- change in store.
What can the water balance be used for?
The water balance could be used to explain droughts or floods. The water balance of an area will change based on a variety of factors especially during seasonal variations of temperature and precipitation.
When is there a water surplus? What does this show us?
In wet seasons, precipitation exceeds evapotranspiration, creating a water surplus. A water surplus means that ground stores fill with water, so there is more surface runoff and higher discharge, so river levels rise.
In the middle months, or drier periods, what happens and what can we see on the graph?
In drier seasons, precipitation is lower than evapotranspiration. Ground stores are depleted as water is used by plants and animals, and some flows into the river channel, but isn’t replaced by precipitation.
