Chapter 9 Water Resources

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Chapter 9Water Resources

• Geosystems 6e
• An Introduction to Physical Geography

Robert W. Christopherson Charles E. Thomsen
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Chapter 9

• You are responsible for pages 245-248 in chapter 9

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Water

• Constantly cycling through the environment
• Water spends time in the ocean, the air, on the
  surface, and underground.
• Hydrologic Cycle the circulation and
  transformation of water through Earths
  atmosphere, hydrosphere, lithosphere, and
  biosphere.
• Water-resource management
• Wells, reservoirs, dams

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Water Budget
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• 97 of Earths water in the ocean, so most
  precipitation and evaporation takes place there
• The bulk of global precipitation comes from ocean
  water

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• 86 of all evaporation traced to ocean
• 14 of all evaporation traced to the land

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Transpiration

• The movement of water vapor through the pores of
  leaves and into plants through roots from soil
  moisture.

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Evaporation

• The movement of free water molecules away from a
  wet surface into the air that is less saturated.

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• Water spends 10 days (on average) in the
  atmosphere
• Water spends 3,000-10,000 years in deep-ocean
  circulation, groundwater aquifers, glacial ice

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End of Chapter 9

• Geosystems 6e
• An Introduction to Physical Geography

Robert W. Christopherson Charles E. Thomsen
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Chapter 10Global Climate Systems

• Geosystems 6e
• An Introduction to Physical Geography

Robert W. Christopherson Charles E. Thomsen
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Climate

• Climate is weather averaged over time over
  broader geographic areas.
• Usually averaged over 30-yr periods.
• Climatology is the study of climate over both
  time and space.
• One central goal is to determine climatic
  regions, areas with similar weather statistics.
• Another central goal is to analyze climate
  variability over time (like global warming!).

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Ecosystems

• Climates influence the location of an ecosystem
• Ecosystem the natural, self-regulating
  communities formed by plants and animals in their
  nonliving environment.
• Biome A large terrestrial ecosystem
  characterized by specific plant communities and
  formations

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Biomes

• Usually named after the predominant vegetation in
  the region
• Examples savanna, forest, grassland, tundra,
  desert
• Each biome is a collection of animals, plants,
  and soils
• Biomes constantly changing and adapting to
  changes in climate

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Climate Classification

• Provides an organized and manageable source of
  information that simplifies rather complex
  patterns in the real world
• Also gives us a common short hand way to describe
  climates quickly and easily
• By using 2 principal climatic components,
  temperature and precipitation, general climate
  types are revealed

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Koppen

• Koppen climate classification
• Developed 1918
• Developed to correlate the spatial distribution
  of plants to the spatial distribution of climate
• The Koppen-Geiger climate classification system
  is the updated version in your text

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Köppens Climate Classifications
Primary Letters

• Tropical Climates (A)
• Average temp of every month gt 18ºC
• Mesothermal Climates (C)
• Coldest month average temperature lt 18ºC but
  gt-3ºC
• At least 1 month average temperature gt 10ºC
• Microthermal Climates (D)
• Average temperature of warmest month gt10ºC
• Average temperature of coldest month lt -3ºC

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Köppens Climate Classifications
Primary Letters

• Polar Climates (E)
• Average temperature of all months  lt 10ºC
• Dry Arid and Semiarid Climates (B)
• Evaporation gt precipitation
• Highland (H)

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Köppens Climate Classifications
Secondary Letters

• These letters are based primarily on seasonal
  precipitation
• f adequate rainfall all through the year, no
  distinct dry season
• w winter dry, if 70 or more of annual rainfall
  occurs in summer
• s summer dry, if 70 or more of annual rainfall
  occurs in winter
• m extremely wet summer monsoon. A climate
  only.

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Köppens Climate Classifications
Secondary Letters

• For B climate only
• S semiarid steppe
• W arid desert
• which results in either BS or BW.
• For E climate only
• T tundra
• F perpetual frost permanent ice
• which results in either ET or EF.

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Köppens Climate Classifications
Tertiary Letters

• The third letters in the system are based
  exclusively on seasonal and annual temperature
• a hot summer, warmest month gt 22C C and D
  only
• b warm summer, warmest month lt 22C C and D
  only
• c cool summer, lt 4 months over 10C C and D
  only
• d very cold winter, coldest month lt -38C D
  only
• h dry-hot, annual temperature gt 18C B only
• k dry-cold, annual temperature lt 18C B only

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Köppens Climate Classifications
Examples of Combinations

• Af Tropical Rainforest climate type
• Am Tropical Monsoon climate type
• BWh Low-Latitude Hot Desert climate type
• Cfa Humid Subtropical climate type
• Csa Mediterranean climate type
• Dfb Humid Continental climate type
• ET Tundra climate type

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World Climate Classification
Figure 10.5
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Tropical Climates (A)

• Tropical Rain Forest Climates (Af)  
• Tropical Monsoon Climates (Am)  
• Tropical Savanna Climates (Aw)
• Consistent daylength and insolation input
• consistent warm temperatures
• Dominance by ITCZ
• Shifts seasonally with high sun period
• Warm ocean currents, unstable maritime air masses

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Tropical Rain Forest and Monsoon
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Arid and Semiarid Climates (B)

• Köppen system
• W Desert (arid), S Steppe (semiarid)
• h hot (mean annual temp gt 18C)
• usually found in lower latitudes
• k cold/cool (mean annual temp lt 18C)
• usually found in the midlatitudes
• Low-Latitude Hot Desert Climates (BWh)  
• Midlatitude Cold Desert Climates (BWk)  
• Low-Latitude Hot Steppe Climates (BSh)  
• Midlatitude Cold Steppe Climates (BSk)  

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Arid and Semiarid Climates (B)

• Potential for evaporation exceeds rainfall
• Cover 35 of Earths surface
• Most extensive geographically of the major
  climate groups
• One-third of U.S. is classified as arid/semiarid

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Arid and Semiarid Climates (B)
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Mesothermal Climates (C)  

• Humid Subtropical (Hot-Summer) Climates (Cfa)  
• Humid Subtropical (Winter-Dry) Climates (Cwa)
• Marine West Coast Climates (Cfb, Cfc)  
• Mediterranean Dry-Summer Climates (Csa, Csb)  

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Mesothermal Climates (C)  

• Humid Subtropical (Hot-Summer) Climates (Cfa) C
  warmest month above 10ºC, coldest month above
  -3ºC seasonal climates
• a hot summer, warmest month above 22ºC
• f year-round precipitation
• w winter dry (gt 70 of rainfall concentrated in
  summer months)

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Mesothermal Climates (C)  

• Humid Subtropical (Winter-Dry) Climates (Cwa) C
  warmest month above 10ºC, coldest month above
  -3ºC seasonal climates
• a hot summer, warmest month above 22ºC
• w winter dry (gt 70 of rainfall concentrated in
  summer months)

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Mediterranean Climates (Csa, Csb)

• Wet winters, dry summers s
• 70 of precipitation in winter

Marine West Coast Climates

• Mild winters, cool summers
• Unusual climates for their latitude, extending
  close to Arctic Circle.
• Maritime polar air masses (mP) dominate.

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Mesothermal Climates (C)  
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Microthermal Climates (D)

• Also called cool temperate or snow climates.
• Average temperature of warmest month above 10C.
• Average temperature of coldest month below 0C.
• Distinct strong seasonality in temperature ranges
  throughout the year.
• 21 of land surface in Microthermal climates.
• Occurs due to continental locations (cP air
  masses common).
• In Southern Hemisphere, found only in highlands.

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Microthermal Climates

• Humid Continental Hot-Summer Climates
• Dfa, Dwa
• Humid Continental Mild-Summer Climates
• Dfb, Dwb
• Subarctic Climates
• Subarctic Cool-Summer Dfc, Dwc
• Subarctic Extreme-Winter Dfd, Dwd

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Microthermal Climates (D)

• Humid Continental Mild-Summer Climates (Dfb, Dwb)
• Found poleward of Dfa and Dwa climates.
• Cold temperatures in winter primarily due to
• continental locations
• higher latitudes
• cP air masses
• Less precipitation than hot summer climates
• Heavier snowfall

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Microthermal Climates (D)

• Subarctic Climates (Dfc, Dwc, Dwd)
• Found poleward of Dfb and Dwb climate.
• Extensive geographically
• North America, stretching from Atlantic to
  Pacific.
• Eurasia, stretching from Scandinavia to the
  Pacific.
• Subarctic extreme-winter found only in eastern
  Asia
• Most extreme temperature ranges of all climates
• Extremely cold temperatures in winter primarily
  due to
• continental locations Siberian High in winter
• higher latitudes
• cP air masses

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Microthermal Climates (D)
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Polar and Highland Climates

• Tundra Climate (ET)
• Ice Cap and Ice Sheet Climates (EF)
• Polar Marine Climate (aka Polar Maritime) EM
• More moderate than other two polar climates
  (why?)
• No month below -7C (20F), but not as warm as
  tundra climate
• Low annual range of temperature
• Exists only along very fringes of highest
  latitudes
• Bering Sea (Alaska, Russia), southern Greenland,
  northern Iceland, Norway)

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Polar and Highland Climates