2p61 Final content Flashcards
What is the hydrological cycle?
The continuous movement of water within the Earth and atmosphere, involving processes like evaporation, condensation, precipitation, and infiltration.
What drives the hydrological cycle?
The sun, through its energy, which causes evaporation from the Earth’s surface.
Define watershed.
An area of land where all the water that falls within it drains into a common outlet, such as a river, lake, or ocean.
What do we use to delineate watersheds?
Topographic maps and elevation data, using the highest points of land as boundaries.
What are sub-watersheds?
Smaller subdivisions of a watershed that drain into larger streams or rivers.
Define a stream.
A body of flowing water, typically a small river, brook, or creek.
What is discharge in relation to streams?
The volume of water flowing through a stream at a given point in time.
How is stream discharge measured?
By calculating the cross-sectional area and flow velocity of the stream.
What do hydrographs show?
Stream discharge over time.
List the components of hydrographs.
- Rising limb
- Peak flow
- Falling limb
- Base flow
How do urban hydrographs differ from natural hydrographs?
Urban hydrographs show a quicker rise and fall due to impervious surfaces, whereas natural hydrographs have a slower, more gradual rise and fall.
How do meandering streams form?
When water flows in a winding, sinuous pattern, eroding the outer banks and depositing sediment on the inner banks.
What are some techniques to restore streams?
Removing obstacles, planting vegetation, and stabilizing banks.
What are the different types of sediment transport?
- Dissolved load
- Suspended load
- Bed load
What is deposition in the context of sediments?
Occurs when the stream’s velocity decreases.
What factors govern flooding?
- Rainfall intensity
- Duration
- Land use
- Topography
- Soil type
Define a flood.
When water exceeds normal levels in a river or stream, causing damage.
What are flood frequency curves?
Curves that show the probability of different sizes of floods occurring at a given location over time.
What is the main force causing mass movement?
Gravity.
Differentiate between shear stress and shear strength.
- Shear stress: The force trying to move material down the slope.
- Shear strength: The material’s resistance to sliding.
What role does water play in slope stability?
It can lubricate materials, causing landslides, or increase cohesion in clay.
List the types of mass movements.
- Falls
- Slides
- Flows
What is the effect of water content on mass movement speed?
Faster movement typically occurs with higher water content.
What methods can be used for slope stabilization?
Reinforcing slopes with vegetation, constructing retaining walls, or using drainage systems.
Define groundwater.
Water stored beneath the Earth’s surface in porous rock or soil.
What is the water table?
The boundary between saturated and unsaturated soil.
What is Darcy’s Law?
Describes the flow of water through porous media, given by Q=K⋅A⋅Δh/L.
What is drawdown?
The lowering of the water table around a well due to pumping.
What impacts can excessive drawdown have?
- Well failure
- Land subsidence
- Contamination of wells
Differentiate between mechanical and chemical weathering.
- Mechanical weathering: Physical breakdown of rocks.
- Chemical weathering: Chemical reactions that break down minerals.
Define porosity.
The amount of empty space in a material.
What does soil texture refer to?
The proportion of sand, silt, and clay.
List the layers of the soil profile.
- O-horizon: Organic layer
- A-horizon: Topsoil
- B-horizon: Subsoil
- C-horizon: Parent material
What is erosion?
The removal of soil or rock.
What contributes to acid rain?
Pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOx).
What are greenhouse gases?
- Carbon dioxide (CO₂)
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Water vapor
What is the ozone hole?
The thinning of the ozone layer, particularly over Antarctica, due to chemicals like CFCs.
Define smog.
A mixture of air pollutants, including ground-level ozone and particulate matter.
What is thermal inversion?
A weather condition where a layer of warmer air traps cooler air near the ground.
What are point sources of pollution?
Pollution from a specific, identifiable source.
What is eutrophication?
The process by which water bodies receive excess nutrients, causing excessive plant growth and oxygen depletion.
Differentiate between biomagnification and bioaccumulation.
- Biomagnification: Increase in concentration of toxins up the food chain.
- Bioaccumulation: Accumulation of toxic substances within an organism over time.
What is the importance of land use planning?
Helps manage land use for different purposes to reduce environmental impact and ensure sustainable development.
List the benefits of land use planning.
- Efficient land use
- Better infrastructure planning
- Minimizing environmental degradation
What role do maps play in land use planning?
They help visualize and analyze land use patterns, guiding informed decision-making.
Differentiate between environmental law and policy.
- Environmental Law: Legally enforceable rules and regulations.
- Environmental Policy: Guidelines aimed at environmental protection but may not always have legal force.
What is a carbon price?
A method of pricing carbon emissions to incentivize reducing greenhouse gas emissions.
What is an example of Canadian-specific environmental law?
The Canadian Environmental Protection Act (CEPA).
What can affect the effectiveness of environmental laws?
While laws like CEPA have led to improvements, challenges remain.
