The Water Balance

Question 1

Soil water budget

Answer 1

Changes in soil water store during the year
Key influence is relationship between precipitation and evapotranspiration

Question 2

1. Soil moisture recharge

Answer 2

Precipitation exceeds evaporation so pores in the soil are replenished through infiltration

Question 3

2. Soil moisture surplus

Answer 3

Soil is saturated and no more water can infiltrate causing increased surface run off

Question 4

3. Soil moisture utilisation

Answer 4

As it warms up potential evapotranspiration exceeding precipitation, water used by plants

Question 5

4. Soil moisture deficit

Answer 5

Deficit of soil water, plants wither wilt or have adaptations to survive dry conditions

Question 6

Discharge

Answer 6

The volume of water passing a point over a given length of time, measures in cumecs

Question 7

How to calculate discharge

Answer 7

Measuring the cross sectional area of the river and multiplying by velocity of water (m/s)

Question 8

River regimes

Answer 8

Variation in discharge of a river over the course of a vpyear

Question 9

Why measure river regimes?

Answer 9

Measured so that river levels can be monitored
Helps flood prediction and management, helps manage water supplies and consumption

Question 10

River Avon discharge

Answer 10

Highest discharge in winter, higher rainfall and less evapotranspiration
Discharge falls in spring and summer

Question 11

Mohawk river discharge

Answer 11

Low temps and long river, low discharge
A lot of precipitation

Question 12

Uk discharge

Answer 12

Evenly distributed through the year, slight autumn maximum, especially in west
Seasonal variations mean that evapotranspiration losses are concentrated in summer