Class Notes (1,000,000)
CA (620,000)
UTM (20,000)
Environment (1,000)
ENV100Y5 (900)
Lecture 40

ENV100Y5 Lecture Notes - Lecture 40: Pore Space In Soil, Drainage Basin, Ocean Current


Department
Environment
Course Code
ENV100Y5
Professor
Barbara Murck
Lecture
40

This preview shows pages 1-2. to view the full 6 pages of the document.
Water&is&what&makes&us&unique
Shapes the surface of the Earth
Allows for life
Makes Earth different from all other planets!
Exists in all 3 states (solid, liquid, gas)
Atmosphere
On surface
Under the ground
Important in moving heat from equator to the poles
Rises as vapour; falls as rain/snow
Water in the atmosphere helps to move the heat
Water on surface
Ocean currents
Sculpts terrestrial landscape (shaped by water - carves out river valleys)
Carrier for many substances
Water is locked up in minerals in the Earth’s mantle
Makes the mantle elastic; affects the dynamics of plate tectonics
May be largest water reservoir on the planet
Unknown how much cycles between internal & surface reservoirs through
tectonics
Mantle probably largest water reservoir
Hydrology is “water science”
Study of water in the hydrosphere, both on and under the ground
Movement, distribution, quantity, quality
Reservoirs, processes, ecosystems
Freshwater = few dissolved salts
Only 2.5% of Earth’s water is fresh
Most of this is tied up in glaciers and ice caps
We can approach the hydrologic cycle from a systems perspective
Reservoirs: Ocean; ice caps and glaciers; then groundwater
Processes: Precipitation, surface runoff, infiltration, percolation (physical
process where liquid runs into spaces between tiny solids), evaporation,
transpiration
Local variations affect supply, and cause problems like floods and
droughts
Fluxes: Global hydrologic cycle maintains mass balance, total amount of
water is fixed
Solar energy and gravity drive the hydrologic cycle
Solar energy: evaporation (heats up), transpiration (plants), condensation
(warm vapor hitting cool surface). Sun = thermal energy
Gravity: precipitation, runoff (slope = more erosion), groundwater
percolation
Surface freshwater - Rivers and streams, springs, lakes and ponds, wetlands
Rivers shape the landscape
Water from rain, snowmelt, and springs runs off over the surface
Tributary = a smaller river flowing into a larger one
Surface runoff (sheetflow) organizes into rills and gullies, then streams
and rivers
Erosion is the work of rivers carrying sediment to the ocean
A drainage basin is a local hydrologic unit
Drainage basin = catchment = watershed = area drained by one river
Catchments are separated from one another by divides
Catchments have inputs and outputs
Groundwater
Water located beneath the Earth's surface
In soil pore spaces; fractures of rock formations
Largest unfrozen freshwater reservoir
Aquifers store and transmit water
Aquifer: underground layer of water-bearing permeable rock, gravel, sand,
or silt
Confined aquifer: between impermeable layers
Unconfined aquifer: water seeps in from above
Unsaturated zone: some air, some water
Saturated zone: completely filled with water
Water table: top of saturated zone (ie. Sponge)
Aquiclude: zone that prevents water from moving among aquifers
Pearched water tables
Residence time may be thousands of years
Canada: much more water underground than on the surface
26% of Canadas population depends on groundwater (mostly rural)
Groundwater flow is controlled by gravity
Where water table intersects surface = surface water
Recharge = water flows into aquifer via precipitation/ infiltration
Discharge = water flows out of aquifer via percolation/
streams/springs/ocean
In many regions, water table; recharge & discharge vary seasonally
(temperate in particular)
Water supplies houses, agriculture, and industry
Water is unequally distributed
Many areas with high population density are waterpoor and face serious
water shortages
1.2 billion people, (20% world pop’n), live in areas of physical scarcity
(500 million people are approaching this situation)
1.6 billion people, (~25%) face economic water shortage (lack necessary
infrastructure to take water from rivers and aquifers).
~ 800 million people do not have access to safe drinking water
> 3.5 million people die each year from preventable water-related disease
There is (already) a global water crisis
By 2025, the world’s population could increase to almost 9 billion people
According to the UN, 2/3 of those people will be living in conditions of
serious water shortage
Global demand for fresh water will exceed availability by 56 percent
43 countries (1.2 billion people) today already face water scarcity
Global water management challenges include:
Urban and rural drinking water and sanitation
Water for industry and agriculture
Protection of aquatic ecosystems
“Holistic” watershed management
Impacts of environmental change on water resources
Canada is criticized for wasteful water consumption
Per capita water use is 28% higher than the average OECD country
Since 1980, Canada’s water use has increased 5x faster than OECD ave.
rate of increase
Chapter(12(+Freshwater(Systems(and(Water(Resources(
Monday,&January&11,&2016
2:31&PM

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

Water&is&what&makes&us&unique
Shapes the surface of the Earth
Allows for life
Makes Earth different from all other planets!
Exists in all 3 states (solid, liquid, gas)
Atmosphere
On surface
Under the ground
Water in atmosphere
Important in moving heat from equator to the poles
Rises as vapour; falls as rain/snow
Water in the atmosphere helps to move the heat
Water on surface
Ocean currents
Sculpts terrestrial landscape (shaped by water - carves out river valleys)
Carrier for many substances
Water is locked up in minerals in the Earth’s mantle
Makes the mantle elastic; affects the dynamics of plate tectonics
May be largest water reservoir on the planet
Unknown how much cycles between internal & surface reservoirs through
tectonics
Mantle probably largest water reservoir
Hydrology is “water science”
Study of water in the hydrosphere, both on and under the ground
Movement, distribution, quantity, quality
Reservoirs, processes, ecosystems
Freshwater = few dissolved salts
Only 2.5% of Earth’s water is fresh
Most of this is tied up in glaciers and ice caps
We can approach the hydrologic cycle from a systems perspective
Reservoirs: Ocean; ice caps and glaciers; then groundwater
Processes: Precipitation, surface runoff, infiltration, percolation (physical
process where liquid runs into spaces between tiny solids), evaporation,
transpiration
Local variations affect supply, and cause problems like floods and
droughts
Fluxes: Global hydrologic cycle maintains mass balance, total amount of
water is fixed
Solar energy and gravity drive the hydrologic cycle
Solar energy: evaporation (heats up), transpiration (plants), condensation
(warm vapor hitting cool surface). Sun = thermal energy
Gravity: precipitation, runoff (slope = more erosion), groundwater
percolation
Surface freshwater - Rivers and streams, springs, lakes and ponds, wetlands
Rivers shape the landscape
Water from rain, snowmelt, and springs runs off over the surface
Tributary = a smaller river flowing into a larger one
Surface runoff (sheetflow) organizes into rills and gullies, then streams
and rivers
Erosion is the work of rivers carrying sediment to the ocean
A drainage basin is a local hydrologic unit
Drainage basin = catchment = watershed = area drained by one river
Catchments are separated from one another by divides
Catchments have inputs and outputs
Groundwater
Water located beneath the Earth's surface
In soil pore spaces; fractures of rock formations
Largest unfrozen freshwater reservoir
Aquifers store and transmit water
Aquifer: underground layer of water-bearing permeable rock, gravel, sand,
or silt
Confined aquifer: between impermeable layers
Unconfined aquifer: water seeps in from above
Unsaturated zone: some air, some water
Saturated zone: completely filled with water
Water table: top of saturated zone (ie. Sponge)
Aquiclude: zone that prevents water from moving among aquifers
Pearched water tables
Residence time may be thousands of years
Canada: much more water underground than on the surface
26% of Canadas population depends on groundwater (mostly rural)
Groundwater flow is controlled by gravity
Where water table intersects surface = surface water
Recharge = water flows into aquifer via precipitation/ infiltration
Discharge = water flows out of aquifer via percolation/
streams/springs/ocean
In many regions, water table; recharge & discharge vary seasonally
(temperate in particular)
Water supplies houses, agriculture, and industry
Water is unequally distributed
Many areas with high population density are waterpoor and face serious
water shortages
1.2 billion people, (20% world pop’n), live in areas of physical scarcity
(500 million people are approaching this situation)
1.6 billion people, (~25%) face economic water shortage (lack necessary
infrastructure to take water from rivers and aquifers).
~ 800 million people do not have access to safe drinking water
> 3.5 million people die each year from preventable water-related disease
There is (already) a global water crisis
By 2025, the world’s population could increase to almost 9 billion people
According to the UN, 2/3 of those people will be living in conditions of
serious water shortage
Global demand for fresh water will exceed availability by 56 percent
43 countries (1.2 billion people) today already face water scarcity
Global water management challenges include:
Urban and rural drinking water and sanitation
Water for industry and agriculture
Protection of aquatic ecosystems
“Holistic” watershed management
Impacts of environmental change on water resources
Canada is criticized for wasteful water consumption
Per capita water use is 28% higher than the average OECD country
Since 1980, Canada’s water use has increased 5x faster than OECD ave.
rate of increase
Chapter(12(+Freshwater(Systems(and(Water(Resources(
Monday,&January&11,&2016 2:31&PM
You're Reading a Preview

Unlock to view full version