Water is important to plants and animals because...
- It's a source of food and drink
-it provides a habbitat
-it's used for photosynthesis
Water is important to humans because...
-it can be used for sustainable energy
-its used to wash in and to drink
-we can grow plants and crops
-we use it for shipping trade
The hydrosphere = consists of all the water on earth- in seas, oceans, rivers, lakes, rocks and soil- in the atmosphere
The hydrological cycle = the movement of water between land, oceans and the atmosphere
Irrigation = when water is added to crops
Climate change = A lasting change in the weather patterns over a long term period of time
Why is demand for water growing globally?
-Our population is growing rapidly so the earth has the same amount of water but it is needed for more people.
- We are polluting lots of our fresh water
-The global population is becoming wealthier, so we consume more and more water is needed to fit this demand.
- The biggest consumer of water is agriculture.
-Evaporation will increase as temperature rise due to climate change
EXAM QUESTION: Using examples, explain how climate change is likely to alter the hyrological cycle? (6)
As a result of climate change temperatures are rising. Firstly, the might effect the hydrological cycle because the rate of evaporation will be high due to higher temperatures. This means drought will be more likely as more water will be evaporated which may reduce surface flow. Secoundly, ice will melt faster, so in countries, such as Chile, where they rely on ice for water will suffer and it may lead them to bring up more ground water. Lastly, warmer seas may lead to more hurricanes as they create the perfect conditions for them to start. Hurricanes may pull up trees reducing transpiration.
How do humans affect the hydrological cycle?
Destroying landscpaes/ habbitats: deforestation prevents transpiration, bogs/ wetlands being drained for farming reduces surface stores and soil moisture
Climate change: reducing ice store on land increases overland flow, more dorught means harder soil and less infiltration, more intense storms means more overland flow so there is less time for the water to infiltrate which causes flooding and soil erosion.
Diverting rivers: irrigation of farmlands, water for industry, diverted towards major cities such as Las Vagas
Improving drainage: more streamflow but water get there quicker
Extraction of ground water: used for drinking, domestic use, farming, industry, has reduced the size of the water table and is causing some mega cities such as mexico to slowly sink.
Building dams: stops streams flow, increases evaporation
Laying down conreate: used for roads and pavements, drecreases infiltration and increases overland flow.
CASE STUDY: The Aral Sea
Where? The Aral Sea is in the west of kazakhstan, in Central Asia
What Happened? It was once the fourth largest area of fresh water in the world but has now shrunk to 10% of its size. It has fallen in depth by more…