To Learn Flashcards
(23 cards)
Outline how knowledge and understanding of the water and carbon cycles is important in managing climate change.
The carbon cycle regulates global temperature by controlling the amount of CO2 (greenhouse gas) in the atmosphere. Changes in temperature cause change in the water cycle.
Is a drainage basin an open or closed system?
Open
Which is the biggest store of water on Earth and what % of the total global water is stored here?
98%
Where is most freshwater stored?
68% in cryosphere in glaciers and ice caps
How much would sea levels rise if the Antarctic and Greenland ice sheet melted?
66m
Outline the key role that water vapour plays in the atmosphere in terms of life on Earth and climate change.
The amount of water vapour in the air depends on temperature – warmer air can hold more water vapour. Water vapour is a greenhouse gas which leads to higher global temperatures (positive feedback loop).
Aquifers
Large storage of water underground
In permeable rocks
Why does water temperatures increased evaporation?
Warmer air can hold more water
How does digging drainage ditches affect stores and flows?
Increases rate of Transfer of water to nearby rivers increasing risk of flooding
What is a drainage basin ?
An area of land drained by a river and its tributaries
Contour ploughing
On slopes preventing rapid runoff of water
How much lower were sea levels in the last ice age?
120m
How will sea level rise threaten the coast?
Increases rate of erosion
Increases likelihood or flooding
Flooding and erosion impact mangroves and Sand dunes that act as natural barriers
Traditional approaches to management at the coast
Taking direct action along short sections of coastline to stop or slow erosion/reduce risk of flooding using hard and/or soft engineering strategies.
Sustainable approaches to coastal management
More holistic approaches that look at a sediment cell and consider the entire coastal zone and the interaction of human and physical processes. Plans are short, medium and long term with a focus on sustainability.
What principle are SMPs based on ?
Identify the most sustainable approach to managing flood and erosion risk
Main idea between ICZM
Focus on both land and sea in a sediment cell
Interlinked system aiming to coordinate policies affecting the entire zone
Example of ICZM
Seeing how pesticides / fungicides end up in rivers from runoff and eventually oceans affecting marine life
What direction does wind move?
High to low pressure
What happens to waves as they approach the shore?
More friction with sea bad as water becomes shallow
Waves have more elliptical than orbital motion
Increase in height and decrease in velocity and frequency
Difference between currents and tides?
Currents are permanent or seasonal sideways movements of water in seas and oceans
Tides are changes in the water level of seas and oceans
Rip current
Localised powerful underwater current in areas close to the shoreline
Waves cause a build up of water at the top of the beach
Backwash forced down below breaking waves and is channelled into troughs in the beach profile eg. Gap in an offshore sand bar
Longshore current
Waves approach coastline at an angle
Sediment is transported along the shoreline over time
