1. Surface Water and the Water Cycle
Hydrosphere
Surface Water and the Water Cycle

2. Explain the structure and processes within the hydrosphere
Goals for This Unit
Explain the structure and processes within the hydrosphere
Explain how water is an energy agent (currents and heat transfer)
understand the role of water in weather and atmospheric change
use concepts of fluid density to describe global water movement and ocean currents and their effect in distributing heat around the globe
Explain how ground water and surface water interact
understand the concepts and dynamics of river systems with emphasis and examples drawn from NC river systems
list and describe common methods used to conserve both water quantity and quality

3. How Do You Use Water?

4. The Water Cycle
A never-ending natural circulation of water through Earth’s systems powered by the Sun

5. Steps of the Water Cycle
Precipitation – rain, snow, hail, sleet
Runoff or ground seep
Reservoir – living things, snowfields, glaciers, lakes, oceans
Evaporation – from land or bodies of water
Transpiration
Condensation

6. Runoff V/S Ground Seep Vegetation Rate of Precipitation
more vegetation = more ground seep
less vegetation = more runoff
Rate of Precipitation
lighter rainfall = more ground seep
harder rainfall = more runoff
Soil composition
high humus, coarse particles = more ground seep
low humus, fine particles = more runoff
Slope
flatter slope = more ground seep
steep slope = more runoff

7. Effect of Soil Composition
Sand
Silt
Clay
High Humus Content
Low Humus Content
Runoff

8. Stream Systems
Some runoff flows into brooks, creeks, streams and rivers that eventually empty into lakes and oceans
Watershed – all the land area whose water drains into a stream system
Stream load – all the materials (living and non-living) that the water in a stream carries
Carried in three ways – solution, suspension, bed load

9. Solution When material has dissolved in a stream’s water
Dependent upon the material a stream has passed through
High amounts of calcium carbonate and magnesium
Groundwater provides most of the dissolved load to streams
Expressed in parts per million (ppm)

10. Suspension
Particles small enough to be held up by the turbulence of a stream’s moving water
Dependent upon volume and velocity of the stream
Faster moving water = larger particles

11. Bed Load Sediments too large or heavy to be held up by turbulent water
Consists of sand, pebbles, cobbles that are rolled and pushed along the stream bed
Abrasion – particles rubbing and scraping against one another as they tumble in the water
Erodes not only sediments in water but also sides and bottom of stream itself

12. Stream Carrying Capacity
Amount of material a stream can transport
Depends upon velocity and amount of water moving in the stream
Affected by channel slope, depth and width
Discharge – measure of the volume of stream water that flows over a particular area within a given period of time
Discharge(m3/s) = width(m) X depth(m) X velocity(m/s)
As discharge increases carrying capacity increases
Impacted by heavy rain, flooding, rapid melting of snow

13. Floods
Floodplain – broad, flat area extending out from a stream’s bank that is covered by excess water during times of flooding
As flood water recedes it deposits sediments in the floodplain that develop highly fertile soil
Upstream flooding – local
Downstream flooding - widespread
Monitoring of streams is provided by the National Weather Service, weather satellites and the US Geological Survey (USGS)

15. Water Cycle Project Please draw the water cycle Criteria
Must be accurate
Must be neat
Must be on plain paper
Must be colored
DUE Tuesday 25 September

16. Hydrosphere
Stream Development

17. A Stream is Born
Precipitation provides the water for the beginnings of stream formation
Headwater – region where water first accumulates to supply a stream
Stream channel – narrow pathway carved into sediment or rock by stream waters
Stream capture – when a stream erodes the area separating two drainage basins, joins another stream and then draws away its water

18. Stream Valleys V-shaped channels caused by erosion from streams
Grand Canyon, Colorado River
Streams continue to erode until they reach their base level, the point where they enter another stream or body of water
Lowest possible base level is the ocean
Eventually v-shaped valleys erode into broader valleys with gentle slopes

21. Meandering Streams Meander – bend or curve in a stream channel
Velocity differences
Straight stream: fastest in the center, slower on the sides and bottom
Meander: fastest along the outside of a curve, deposition occurs on inside of curve where water slows
Over time meanders become more accentuated
Mouth – area of a stream that empties into another body of water

23. Sediment Deposition Occurs as streams slow (lose velocity)
Alluvial fan – occur when mountain streams flow into broad, flat valleys
Usually found in dry, mountainous regions
Usually composed mostly of sand and gravel
Delta – occur when streams join larger bodies of quiet water
Usually form a triangle shaped deposit
Usually composed of silt and clay particles

24. Alluvial Fan

25. Deltas

26. Stream Rejuvenation Downcutting – wearing away of a streambed
Stops when a stream reaches its base level
Rejuvenation – occurs when downcutting resumes due to land uplift of the stream bed or lowering of the base level
Creates v-shaped valleys
In meanders, creates deep sided canyons

27. Lakes and Freshwater Wetlands
Hydrosphere
Lakes and
Freshwater Wetlands

28. Lakes Form from many sources Man Made Naturally Formed
Streams, runoff, local precipitation, springs, etc
Created two ways
Man Made
Ponds – livestock, fish supplies, attract wildlife
Reservoirs – stores water for human use
Naturally Formed
Oxbow
Landslides
Remnants of prehistoric lakes
Glaciers
Dissolved limestone

29. Glacier Lakes Moraine-dammed Cirque Kettle
Form when glacial moraines dam some depressions and restrict outward flow of water
Cirque
Form when cirques that are carved out by high valley glaciers fill with water
Kettle
Form when water fills depressions left by blocks of ice from melting glaciers

30. Changing Lakes
Exist for long periods of time as long as the supply of water is more than what is removed by evaporation and human use
Some only exist during times of heavy rains
Over time (100,000+ years) will eventually fill with sediment and become part of the landscape

31. Eutrophication
Process by which lakes become rich in nutrients from the surrounding watershed, which results in a change in the kinds of organisms in the lake
Photosynthesis (plants) add oxygen and waste products to the lake
Animals in the lake use the oxygen and add their waste to the lake
Decay of dead animals and plants also uses dissolved oxygen supplies
Amount of dissolved oxygen helps determine the health of a lake and if it can support life

33. Rates of Eutrophication
Increases with addition of nutrients
Nitrogen and phosphorus from fertilizer
Animal wastes
Phosphate detergents
Release of toxins from industry and untreated sewage
Additional nutrients causes excessive algae to grow
Causes organisms that eat the algae to multiply
Overpopulation and decay of large numbers of plant and animals consumes the oxygen supply
The lake eventually dies

35. Freshwater Wetlands Land area covered with water most of the year
Include bogs, marshes, swamps
Have certain soil types that support specific plant species

36. Bogs Receive water only from precipitation Soil is waterlogged
Rich in sphagnum (peat moss)
Peat moss breakdown produces acid
Acidic soil supports unusual plant species
Pitcher plants
Sundew
Venus flytrap

37. Marshes
Common along the mouths of streams and in areas with large deltas
Constant supply of water
Shallow roots of marsh grasses allow for capture of silt and mud that slows water flow and expands the marsh
Diverse wildlife and plants
Birds, fish, reeds, grasses, sedges and rushes

38. Swamps Low-lying areas often near streams
May develop from marshes as they fill-in
Support the growth of larger plants such as trees and bushes
Because of increased shade, marsh grasses begin to die
Present day coal reserves were once swamps 250 million years ago

39. Importance of Wetlands
Help improve water quality
Trap pollutants, sediments, pathogenic bacteria
Provide vital habitat for migratory water birds and other wildlife
Between 1700 to 1985 the US lost 50% of its wetlands
Wetlands are often filled-in to make space for people
New York City (Queens, Brooklyn)
New Oreleans
Washington, DC