Physical Geography Weeks 10+

Components of the Water Cycle

Consists of

• Inputs (Water flowing into the system)

• Outputs (Water leaving the system)

• Stores (Water staying in the system)

Examples for Stages of Water Cycles

Inputs - Precipitation

Outputs - Snowmelt runoff, groundwater movement to streams, evaporation, transpiration

Stores - Lakes, wetlands, soil and aquifer stores, ice, snow, ocean, atmosphere

Water Cycle Control Volume

A volume of the land surface that water enters, exits, and is stored in over time

• aka a watershed, drainage basin, catchment

Watershed, Drainage Basin, Catchment

Area which water funnels into, typically in a valley

• Consists of

  • Drainage Divide

  • Interfluves

  • Valleys

Stream Networks in Watersheds

1st Order - no tributaries

2nd Order - confluence of two 1st order streams

3rd Order - confluence of two 2nd order streams

Drainage Patterns

Damn, Real Tall Rodents Are Pretty Dope

Dendritic, Rectangular, Trellis, Radial/Annular, Parallel, Deranged

Dendritic Drainage Pattern

Tree-like

• Efficient movement of water as streams lengths are short

Rectangular

Right-angle stream intersections

• Formed by jointed/faulty rock terrain

Trellis

Right angles to main rivers, moves down mountain slopes

• Valleys, ridges where rocks have different resistance to erosion

Radial/Annular

Water moves down sideways from central area

• Created by dome structures (volcanos)

Parallel

Parallel streams associated with steep slopes

Deranged

No clear drainage pattern or stream valley

• Ponding created

Drainage Density Formula

Measures efficiency of watershed

D_d = ∑L / A_D

_{Total length of stream divided by area of watershed}

A_D = an area

∑L = total length of streams draining that area

D_d = Drainage density (Km²)

Drainage Density

Positive correlation to average precipitation and soil permeability

River Discharge

Rate of flow of water volume, including sediments

• Volume length of travel per unit time

  • m3 s -1

River Discharge Formula

Q = A x V

Q = discharge m3 s -1 ; A = area; V = avg stream velocity

=

W x D x V

W = channel width D = avg channel depth; V = avg stream velocity

Measuring River Discharge

1. Measure the stream’s width.

2. Make several segments

3. Calculate area of each segment: area = width segment × depth.

4. Calculate discharge of each segment = area × velocity.

5. Add all segment discharges → total flow.

Causes for Discharge Variation

1. Size and Shape of the Watershed

2. Basin geology, permeability of rock type

3. Differences in vegetation type

4. Precipitation, type, distribution

Influence of Basin Size on Streamflow over time

Influence of Land Use on Streamflow over time

Different types of inconsistent rivers

Intermittent - flows part of the year, some groundwater

Ephemeral - flows after precipitation

Perennial - Flows all year, fed by rainfall, groundwater, and snowmelt

Why is Discharge + the Hydrograph important?

1. Water supply - excess precipitation is used by humans

2. Flood predictions

3. Water quality - quality is influenced by chemical, biological processes as water flows through channel

Driving Forces that Influence Coastal Environments

• External Drivers, like solar energy and lunar cycle which cause….

• Wind, weather, tides, and waves, along with human activity which cause….

• Erosion, transportation and deposition which shape….

• Coastal landforms

The Littoral Zone

Typically the highest point where water reaches from storm surges on land to where the water is too deep to carry sediments

• typically 60m depth

• Littoral zone naturally shifts and changes

Wave Refraction

Redistribution of Waves

• Resistant rock refracts the wave energy, which results in differences in erosion

  • formation of coves and bays

• Wave energy highest in headlands (converging), lowest in coves (diverging) which eventually straightens coasts

Tidal Influences on Coastal Erosion

Occur twice daily, caused more by the pull of the moon and less, but to some extent, by the pull of the sun

• Spring tide (new moon and full moon)

• Neap Tide (first and third quarter moon)

Spring Tide

Combined gravity of sun and moon

• when both are on the same side of earth, or when the moon is on the opposite side of the sun

• increased tidal range

Neap Tides

• decreased tidal range

• sun and moon at right angles relative to earth

Wave Action

Friction between wind and ocean surfaces which causes

Wave Details

Caused by energy transfer from molecule to molecule in a circular form

• circular formations get smaller with increasing depth

• with depth becoming shallower, waves slow down and space between crest and trough shrinks

  • height and steepness increases which causes breakers

    • breakers alter geomorphology

Littoral (Longshore) Current

Water current moving parallel to shore

• movement of large amounts of material is called beach drift

• Littoral Drift = beach drift + longshore drift

Coastal Deposition by Water

Landforms created by deposition carried out by water

• Beaches

• Tombolo (island connected to mainland by bar)

• Lagoon (shallow water separated by sand or reefs)

• Bay Barrier - a spit that goes across a bay

Beach locations

Can be found along oceans, seas, lakes, or rivers

Implications of Sea Level Rise

Vulnerable areas

What is the Cryosphere?

All of the frozen parts of the hydrosphere

• Sea Ice (Forms, grows, and melts in the ocean)

• Ice Sheets (Mass of glacial ice (>50000km)) (Greenland and Antarctica)

• Ice Shelves (Permanent floating ice shelves connected to land)

• Icebergs (derived from ice formed on land)

• Snow

• Glaciers

• Permafrost (ground that remains frozen for two or more years)

Glacier (definition + how they are formed)

Large mass of ice on land or ocean

• Accumulation of snow which gets compacted through mass and freeze-thaw cycles (firn)

• compaction and freeze-thaw eventually makes glacial ice (glacial ice)

• quicker formation in wet climates (rockies) than dry climates (Antarctica)

Two main types of glaciers

Continental, Alpine

Types of Alpine Glaciers

Valley Glaciers

• River of ice in a valley formed by a stream

Cirque Glaciers

• Glaciers form in a snowfield of a cirque (bowl)

• Formed by accumulation of snow

Piedmont Glaciers

• Spill/spread out of a confining valley

Tidewater Glaciers

• Glaciers at the edge of the ocean which calve into the sea

Continental Glacier

Continuous mass of ice

• Ice Caps

• Ice Fields

Ice Cap

Miniature ice sheet with a dome shape

• less than 50,000 km²

• polar and sub-polar regions

• flat, high elevation

Ice Fields

Interconnected glaciers that cover mountainous areas

Glacial Formation

Open systems (inputs of snow, outputs of water, vapour, and ice)

• Accumulation zone - part of snowfield where snow collects

• Firn - Multi-year snow that turns into ice

• Firn/Equilibrium Line - Line indicating where snow stays or melts

Mass Balance

Balance between inputs of snow and outputs of meltwater, water vapour, and ice in glaciers

• negative mass balance = size reduction

• positive mass balance = size increase

Ablation Zone

Area of glacier melt and sublimation

Plastic Deformation

Glacier movement, comparable to melted plastic moving

• coarse warping around landforms

• responds to weight, pressure, and gravity

Two Processes of Glacial Movement

Internal Deformation

• Most movement occurs within plastic zone beneath the top layer

• Brittle zone cracks as plastic zone moves

Basal Sliding

• Glacier slides due to meltwater moving through crevasses and acting like a lubricant

Post-glacial landscapes

Polished rock, tarns, U-shaped valleys and fjords, hanging valleys, cirques, horns,

Sorted and Unsorted Glacial Deposits

Sorted = sediment deposits from meltwater

Unsorted = Transport of materials on/within ice

Glacial Drift

Term used for all glacial deposits

Moraines

Lines of rock fragments formed as glacier flows

• lateral = on edges

• medial = in the middle, as two glaciers merge together

rock deposited on ground = till

Erratics

Large rocks left on landscape from glacial melt and flow

Drumlin

Streamlined, elongated hill formed by glacial drift

• shaped like teaspoon bowl

Esker

Long, winding ridge formed by deposited gravel from meltwater flowing on or in a glacier

Soil Makeup

Made of water, air, and particles of minerals and organic matter

• Absorbs 10x more CO₂ than plants

• Filters water

• Is a habitat

5 Controls of Soil Development

Parent Material

Climate

Biological Activity

Relief and Topography

Time

Parent Material

Underlying material (bedrock) forms the soil

• Imparts its characteristics to the soil

  • composition, texture, chemistry

Climate

Temperature and moisture characteristics influence soil formation through chemical reactions and breakdown of organic material

Biological Activity

Living organisms which alter the acidity and alkalinity of the soil

• Things in and on the soil

Relief and Topography

Slopes that are too steep do not have good soil, as gravity and erosion sweep layers of soil

• Flat areas have better soil due to less erosion but can become waterlogged

• Slope orientation plays an important role

Time

Rate of soil development depends on parent material characteristics and climate

• warm, humid climates = faster soil development

Soil Profile

Vertical section of soil from top to extent of plant roots OR bedrock

Pedon

Smallest unit of soil with soil characteristics in layers

Horizon

Layers of soil, parallel to Earth’s surface

O, A, E, B, SOLUM, C, R

OMA ATE EVERY BROWNIE SO CRAP, RIGHT?

O Horizon

Surface

Organic material with humus (decomposed organic material)

A Horizon

Mineral matter mixed with some humus

E Horizon

Coarse sand with silt

• Eluviation

  • water moves through and carries with it minerals to lower horizons

B Horizon

Where dissolved minerals and nutrients accumulate

• Illuviation

Solum

Living Layers

• A, E, and B layers

C Horizon

Weathered bedrock and regolith

R Horizon

Bedrock at the bottom of the soil profile

Soil Properties

Important indicator of Soil Fertility

Can Tall Socks Cool My Porcupine?

• Colour

• Texture

• Structure

• Consistence

• Moisture

• Porosity

Soil Colour

Indicates presence of minerals, as well as depth of water table, chemistry, formation

• Red = iron oxide

• Black = organics

• Pale hues = carbonates

Texture

Mixtures of particles of varying sizes

• classified using a Soil Texture Triangle

Soil Structure

Size and shape of particles

• Ped = smallest cluster of particles, shape of which is used to determine structure

Soil Consistence

Cohesion of particles

• related to texture and structure

• reflects resistance and breaking with various moisture

Soil Porosity

Spaces holding air, gases, and water between particles

• Important for water movement, drainage, and ventilation

• High porosity = large spaces

• Low porosity = small spaces

• Influenced by roots, earthworms, and human activity

Soil Moisture

Moisture within soils

• Field Capacity = maximum water available for roots after large pores have drained

• Low Field Capacity = wilting plants

Ecosystems

Plants and animals living in their non-living environment

• Open systems, no sharp boundaries

Ecology

Study of the relationships between organisms and their environment

Biogeography

Study of the past/present spatial distributions of animals

Population

Group of interacting and interbreeding organisms

Community

Different populations living together and interacting

Biome

Large area of similar vegetation and climate conditions

Biotic and Abiotic Subsystems Which Shape Populations

Biotic

• Producers (plants), consumers (animals), decomposers (worms, fungi, bacteria, mites)

Abiotic

• Solar radiation, Gas, Water cycles, Mineral cycles

Abiotic Feedback

Abiotic processes influence surrounding environment

• sunlight and water influence vegetation growth

Vegetation changes abiotic surroundings

Major Abiotic Factors + Definition

Abiotic Factors influence where species are found as well as how they grow, interact, and die

1. Air and Soil Temperature

2. Photoperiod

3. Amount of Precipitation

Diurnal Processes of Gas Exchange in Photosynthesis

Daytime: Intake CO2 and water, Output O2 and water vapour

Nighttime: Intake O2 and water, Output O2 and water vapour

Stomata

Pores on underside of leaf surface

• opening and closing create vacuums which pull water up from roots

• CO2 enters, O2 and water leave stomata

Life Zone

Zone of flora and fauna with elevation and latitude from polar regions to tropics

Temperature and Precipitation Influences on Ecosystem

Strong relationship between productivity, sunlight, and precipitation

• Highest productivity in warm, wet climates

Limiting Factors and Spatial Distribution

Physical, chemical, and/or biological phenomena which limit the range of a living organism

Ecological Succession

Transition from one biotic community to another when an ecosystem is disturbed and most, or all of its species are eliminated

• pioneer species are the first to colonize an area

Facilitation

The presence of a species drives succession by improving conditions for subsequent species

Climax Ecosystem

Final stage of succession

Primary and Secondary Succesion

Primary

• invasion and progression from one community to another

• Occurs in an area that lacks soil

Secondary

• Occurs following disturbance

• Plants and animals move into a disturbed area

What do wildfires need to burn?

Fuel, weather, topography

Succession following broadleaf fire

Pioneer Species

• 1-2 years - annual plants

• 3-4 years - grasses and perennials

Intermediate Species

• 5-150 years - grasses, shrubs, young pines, oaks, hickory

Complex Species

• 150+ years - mature oak and hickory forest

Succession following Boreal/Montane Fire

0 years - herbaceous annuals

2-5 years - grasses, shrubs, pine, seedlings

5-20 years - aspen, birch regeneration, pine saplings, spruce

20-80 years - aspen, pine, spruce

80+ years - climax ecosystem with pine, spruce

Environmental Factors Affecting Organisms

Condition - Something that varies in time and space but is not used up (water in an ocean, warm air in a desert)

Resource - A factor that is consumed by organisms which can result in limitations

Vegetation Fuel Characterization

Ground and surface fuels

Ladder Fuels

Crown Fuels