5.3-water Bugwts

Question 1

What do water budgets show

Answer 1

Water budgets reflect the natural annual balance between inputs and outputs in a given river area

Question 2

What is the formula used to work out water budgets

Answer 2

Precipitation = channel discharge (Q) + Evapotranspiration +/- change in store

Question 3

What is soil moisture surplus

Answer 3

Soil moisture surplus is when precipitation is greater than potential evapotranspiration and the soil water store is full. This means there is a surplus of soil moisture for plant use, runoff into streams and recharging groundwater supplies. The soil is at field capacity and water is now running off

Question 4

What is soil moisture utilisation

Answer 4

Soil moisture utilisation is when moisture from the soil stores is being used by vegetation/humans as the precipitation rate is less than evapotranspiration

Question 5

What is soil moisture recharge

Answer 5

Soil moisture recharge occurs when moisture from precipitation infiltrates and percolates into the stores to repay the soil moisture utilisation/ defecit

Question 6

What is soil moisture defecit

Answer 6

Soil moisture deficit occurs when there is not enough water left in the soil to match potential evapotranspiration. Rivers run dry and drought ensues

Question 7

What is field capacity

Answer 7

Field capacity is the normal amount of water that can be held in the soil

Question 8

What is precipitation

Answer 8

Precipitation is the input of water from sleet,snow, rain or hail

Question 9

What is potential evapotranspiration

Answer 9

Potential evapotranspiration is the amount of water that could be lost by evapotranspiration if their was sufficient moisture available

Question 10

What is actual evapotranspiration

Answer 10

Actual evapotranspiration is the amount of water that is lost through transpiration (release from leaves) and evaporation (heating of water on surfaces) to the atmosphere

Question 11

What conditions do there need to be for a positive water balance

Answer 11

For a positive water balance precipitous needs to be greater than evapotranspiration

-a positive water balance will cause a flood

Question 12

What is required for a negative water balance

Answer 12

For a negative water balance evapotranspiration needs to be greater than precipitation

A negative water balance creates drought risk