AS The Hydrosphere Flashcards
Per capita
per person, total use divided by the population
Human impacts on the water cycle
Deforestation, Agriculture, Urban development, Global Climate change, Abstraction (from rivers, reservoirs and aquifers)
Impacts of the over abstraction of water from aquifers
subsidence, lowering of the water table, reduced supplies, loss of surface water features, saltwater incursion
Water treatment Aeration
aeration of water to encourage aerobic bacteria which break down organic material (faecal matter)
Monitoring water levels in an aquifer
water table in boreholes and wells, NASA GRACE satellites monitor gravity which is determined by mass of water underground.
Aquifer
A rock which contains water that is abstracted by humans.
Water treatment Desalination
the removal of dissolved salts from seawater to produce fresh/potable water
Estuary barrage
a reservoir created by building a dam across an estuary, less land use conflicts, harmful to inter-tidal habits
Water treatment Distillation
the removal of dissolved salts by heating or boiling and condensing and collecting steam
Water treatment Filtration
another method of removing suspended solids and organic matter after sedimentation
Water treatment Activated Carbon filters
used to remove (adsorb) organic chemicals such as pesticides
Water treatment Fluoridation
Tertiary water treatment used in some areas to improve dental health
Water treatment Ion Exchange
Used to remove toxic metals such as lead, mercury and arsenic, can also be used to remove calcium and magnesium from hard water.
Water treatment Flocculation, coagulation and clarification
the addition of flocculants which remove the electrostatic charge on clay particles which then coagulate and form floc which then settles and can be removed
Hydrology
The study and understanding of the movement, distribution and properties of water in the environment.
Hydrosphere
All the water on Earth, found in solid, liquid or gaseous form in a variety of reservoirs, including the oceans, ice caps, rivers and lakes, soil, groundwater, atmosphere and living organisms.
Inter-basin transfer
The movement of areas with surplus water to areas of shortage via canal or pipeline eg Wales to England
Primary water treatment
the first stage of water treatment which includes sedimentation
Water treatment Sedimentation
water remains static in pools, tanks or lagoons and suspended solids such as silt settle
Features and structures required for the formation of an aquifer
porous and permeable rock to hold the water with impermeable rock below
Aquifer recharge
the inflow of water via precipitation, infiltration and percolation through soil and rock to the aquifer.
Residence time
the average time a water molecule will spend in a given reservoir of water, can range from hours to thousands of years depending on the reservoir.
Water treatment Reverse osmosis
an energy intense method of removing dissolved salts by forcing saline water through a semipermeable membrane which separates the water molecules from salts
Saltwater incursion
the flow of water from the sea into aquifers when the water levels in the aquifer drop to below sea level due to drought or over abstraction. Contamination with salt makes the water unsuitable for drinking and agriculture.
Water treatment Screens
the removal of large items such at plastic bottles, wood and textiles using screens or grids
Secondary water treatment
Water treatment to further reduce the amount of organic matter and suspended solids such as aeration tanks or trickling filter beds
Subsidence
the sinking of the ground due to compaction of rocks and sediments where pores were once filled with water. Damages buildings, structures and pipelines.
Tertiary water treatment
further water treatment for human consumption or discharge to environmentally sensitive areas includes the removal of pathogens using ozone, UV or chlorine and the removal of phosphates using iron (III) sulphate.
Water Pretreatment
Water treatment prior to primary treatment that includes the use of screens, grids and grit traps
Impacts of reservoirs and dams
large body of water creates microclimate, sedimentation in the reservoir (containing nutrients), lag of nutrients downstream, dam causes migration barrier, change in habitat - increase in freshwater habitat upstream, decrease downstream
