Environmental Management - Chapter 2 - The Hydrosphere

Environmental ManagementChapter 1 – The Hydrosphere

Global Freshwater stores

infiltration

interception

Groundwater flow

The water cycle

• Evaporation – when water droplets get converted to water vapor due to heat, in the atmosphere.

• Condensation – when water vapor is cooled down.

• Precipitation – cooling of water vapor and reaching back to the surface.

• Surface run-off – Water that flows from the ground to some water body.

(Contd…)• Transpiration – when water is lost by plants

and trees.• Evapo-transpiration – the total water lost by

land and plants.• Groundwater flow – when the remainder

water runs sideways off the ground.• Infiltration – when remaining water seeps

downwards into the ground.• Interception – precipitation prevented to

directly fall on the ground by trees and plants.

Climate

Soil

Natural Vegetation

Animals

An e

cosy

stem

Incr

easi

ng d

eman

d fo

r wat

er

Rising world population

More irrigation water used for food production

Increase demand for fresh water

More water used at homes

Improved standards of living

Water use per person

Ads and Disads of Dams

• Water supplies are assured throughout the whole country/region.

• More farmland can be reclaimed

• Helpful for water-poor countries

• HEP from dams provides electricity

• People are forced to move from land about to be flooded

• New farmland is usually not of good quality

• Ecosystems destroyed• Animal habitats lost

Why access to safe water is higher in

urban areas

Cities are more

wealthy places with

factories and offices

Easier to put pressure on

the politicians / leaders to

make improvements

On average, people’s incomes

are higher

Wealthy people are more likely

to live in cities

Water pipes are easier & cheaper to build when a

lot of people live close together

Why access to safe water is lower in rural

areas

Rural areas are

more poorer areas.

Harder to put pressure on

the politicians / leaders to

make improvements

Rural areas are poorer

places

Wealthy people are more likely

to live in cities

Water pipes are harder and

expensive to build when a lot of people live far

away

100% precipitation40%

evapotranspiration

10% run-off

50% groundwater

100% precipitation25%evapotranspiration

45% run-off

30% groundwater

Immediate Short-term Long-term

Loss of human life Houses destroyed factories and work places flooded out livestock carried away Crops ruined road and rail bridges washed away communications disrupted

people in need of medical treatment for injuries homeless people people suffering from water-related diseases shortage of safe drinking water food shortages problems of moving

repair and build new houses replace bridges, roads and railway lines

Effects of a major flood

Decrease in tree growth Reduced crop yields Reduced stream flows Reduced water supply Dry conditions in some biomes Conflict between farmers and urban dwellers

Effects of a drought