3. Water balance

Question 1

What is the water budget?

Answer 1

The balance between inputs and outputs in the water cycle, often measured annually.

Question 2

What occurs when there is a positive change in the water balance?

Answer 2

When moisture is being added to the store (water intake is greater than water loss)

Question 3

What occurs when there is a negative change in the water balance?

Answer 3

When moisture is being removed from the store (water intake is less than water loss)

Question 4

What is the water budget dependent on?

Answer 4

• type, depth and permeability of the soil and bedrock

Question 5

Define soil moisture recharge.

Answer 5

When water is being added into the soil or drainage basin (precipitation exceeds evapotranspiration.

Question 6

Define soil utilisation.

Answer 6

When soil moisture is being used by plants to grow (evaporation exceeds precipitation so soil water is used)

Question 7

Define soil moisture deficit.

Answer 7

When outputs exceed inputs so the soil is dry and in deficit, plants may wilt and stop growing.

Question 8

Define soil moisture surplus.

Answer 8

When inputs exceed outputs so the soil will be wet (water surplus) and there might be water stored on the surface of the ground.

Question 9

Define discharge.

Answer 9

The volume of water passing a certain place in a specified amount of time.

Question 12

What is a soil moisture budget?