1.3 River environments are of great importance to people and need to be sustainably managed

Question 1

List the uses of water:

Answer 1

• Agriculture - To water plans
• Industrial - Heated to make steam, cooling down reactors
• Domestic - Household such as cooking, drinking and cleaning, and recreational swimming
• Environmental - Preserving water in dam

Question 2

What is the importance of water?

Answer 2

• Essential to all life
• Vital to process of economic development
• Only 3% fresh water and over 75% of fresh water locked up in glaciers and snow and 20% ground water

Question 3

Reasons for demand of water:

Answer 3

• Population growth more water needed
• Development raises demand of water
• Rising standard of living
• Rise in agricultural productivity
• Industrialization and electricity use

Question 4

List the supplies of water:

Answer 4

• Rivers and lakes
• Reservoirs - artificial lakes by building a dam
• Aquifers and wells - Groundwater stored in rocks called aquifers

Question 5

Define water surplus:

Answer 5

Areas where balance is positive and supply exceeds demand

Question 6

Define water deficit:

Answer 6

Areas where balance is negative and demand exceeds supply

Question 7

Define water neutral:

Answer 7

Areas where the supply and demand are equal

Question 8

List reasons as to why water quality is important:

Answer 8

• Important for growing crops, livestock, drinking, cooking and washing.
• Polluted water threatens human health
• Water may be worse in dry areas
• Pollution affects water quality

Question 9

List sources of water pollution:

Answer 9

• agriculture:
  deforestation
  fertilizers
  liquid from farm silage and slurry
• industry:
  taking cooling water and returning it at a higher temperature
  spillages from industry
  working of metallic minerals and heavy use of water
• domestic purpose:
  discharge of untreated sewage
  use of river for washing clothes and bathing
  emptying highly chlorinated water such as water from pools

Question 10

List the treatments of water:

Answer 10

• chlorination - to control any biological growth
• aeration - remove dissolved iron and manganese
• sedimentation - remove suspended solids
• filtration - remove the sediments
• disinfection - kill bacteria

Question 11

How many people are estimated to not having water?

Answer 11

1 billion people are estimated to not having water

Question 12

Causes of river flooding and description:

Answer 12

• steep-sided channel: river channel surrounded by steep slopes causes fast run off
• lack of vegetation or woodland: surface run-off will be high as trees won’t intercept
• impermeable rock: water cannot percolate through rock layer
• urbanization: consists largely of impermeable concrete which doesn’t allow infiltration
• deforestation, overgrazing and over cultivation and population pressure: causes soil erosion and sediment to go into river decreasing cross sectional area
• discharge: rainfall intensity, monsoons and snow melt etc increase discharge

Question 13

List some flood management techniques and describe them:

Answer 13

• Dams: Water held back by dam reservoir released in controlled manner controls discharge
• Afforestation: trees planted by river and greater interception of rain lower discharge
• River engineering: channel widened and deepened, channel straightened, course altered to divert flood water
• managed flooding: allow flooding in places to prevent it in other areas
• planning: enforce regulations keeping people out of risky areas
• Can be predicted analyzing weather and river regime