Hydrosphere Flashcards
What human impacts can affect the hydrological cycle
Deforestation, agriculture, urban development, global climate change
What are the environmental effects of reservoirs
Can create new habitats but lose old one Prevent migration of some species River regime downstream of dams Sedimentation Microclimates
What is Eutrophication
the excessive richness of nutrients which can cause excessive growth of plants
Define Interception
precipitation that doesn’t reach the soil but instead is intercepted by leaves and branches
Define infiltration
precipitation/water soaks into sub-surface and moves through cracks and pore spaces
Define percolation
the process where rainfall seeps underground
Define runoff
precipitation that did not get infiltrates or evaporated
Define water table
the upper level of an underground surface in which the soil or rocks are permanently saturated with water
define groundwater
water held underground in the soil, pores and rocks
Abstraction
taking water from natural sources for a use
Define screening
running water through a grill to remove more less dense solids
Define aeration
putting air into the water to prevent anaerobic respiration
define flocculation
chemical (allum) is added to create a neutral bond to allow particle (clay) to bond to it
Filtration
Filtering the water through chalk or sand to remove any last impurities
2 ways river regime downstream of dams may provide water
Regulate river flow
Keep habitats
How is sedimentation important
fertilise floodplains, counteract erosion
What is a microclimate
a large body of water may change the local climate
What is an aquifer
a large body of rock that holds water which is exploited as a resource
Define porosity
a measure of space in rocks that can hold water
Define permeability
how easy it is for fluids to flow through the rocks
Define associated geological structures
rock below must be impermeable to prevent escape of water
What is aquifer recharge?
Where the water into the aquifer is greater than that leaving it
5 ways aquifers can be overexploited
Changes in surface hydrology Ecological impacts Saltwater incursions Subsidence Reduced supplies
How does NASA monitor aquifer depletion
GRACE satellites - their orbit is affected by gravity which is influenced by water mass
define sterilisation
removing all the bacteria and microorganisms usually involves chlorine
define pH adjustment
Adjusting the pH usually with lime to neutralise it
define ion exchange
used in areas with hard water calcium and magnesium are removed and then replaced typically with sodium
define service reservoir
water is stored when it is waiting to be used
4 ways the demand for water can increase.
Increase in population
Increase in per-capita with increased affluence
Increased irrigation of farmland
Industrialisation
What are the 3 features of aquifers?
Porosity, Permeability, Associated geological structures
How can new sources of water be exploited?
Rainwater collection
Rivers
Reservoirs
What are the 4 main features that affect the usefulness of a river?
Total annual water flow
Flow fluctuations
Level of natural contaminants
Pollutants from human activities
What are the 8 factors affect reservoir site selection?
Topography Geology Catchment area Water supply Pollution risk Sedimentation Infrastructure Existing land use and land conflicts
What is an estuary barrage?
Freshwater reservoir created by building a dam across an estuary
Why is saltwater not often used?
Desalination is very expensive and energy intensive
How does river-regulation reservoirs work?
During dry seasons water is used to keep the flow rate the same and during the wet season the water is stored in the reservoir.
What are inter-basin transfers?
Using canal and pipe systems to transfer water from area with surplus to areas with shortages.
How does afforestation help?
Helps to reduce soil erosion
Reduces rate of flow into river which helps to reduce flooding
What are 3 ways to reduce water usage?
Low water appliances
Xeriscaping
Low volume irrigation
What are examples of water pollution control?
Oil pollution control Sewage treatment Acid mine drainage Control of heavy metal waste Landfill leachate treatment Buffer strips next to rivers to reduce fertiliser runoff
2 ways water waste can be reduced?
Repairing leaking pipes (20% loss)
Use of water metres
