1. Surface Water and Groundwater

2. Running Water and Groundwater
% of where the Earth’s water is located
Oceans (salt water) – 97 %
Freshwater trapped in Glaciers/ice – 2 %
Freshwater available to us - < 1 %
Water cycle - the continuous circulation of earth’s water supply
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3. Elements of the Water Cycle
Evaporation = liquid to gas
Condensation = gas to liquid (forms clouds)
Precipitation = water returns to earth (rain, snow, ice, sleet, etc.)
Infiltration = water that soaks into ground
Runoff = water that flows across the ground
Transpiration = water that plants release into the atmosphere (gas to liquid)

4. Water Cycle

5. Water Cycle (cont.) The Earth’s water cycle is balanced
Earth’s annual precipitation = the amount that evaporates
Local imbalances do exist like droughts and floods

6. Stream Flow Velocity – distance water travels in a period of time
Some are slow, some are fast
Highest velocities are in the middle of the channel when it is straight
When it bends, the velocity is highest in the outside bank/bend
Ability of a stream to erode & transport materials depends on velocity

7. 5 Stream Velocity Factors
Gradient = slope (how steep or flat)
Shape = crooked vs straight
Size = wide vs narrow & deep vs shallow
Roughness = smooth vs rough
Discharge = the volume of water flowing past a certain point per unit of time (m3/s)

8. Stream Profile
Cross sectional view of a stream
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9. Stream Profile Changes
Decrease as you go downstream
Gradient
Roughness
Increase as you go downstream
Discharge
Velocity
Depth
Width
The ability of a stream to erode increases as the discharge increases.

10. French Broad River Headwaters
West Fork, French Broad River
North Fork, French Broad River

11. French Broad Decreasing Gradient Going Downstream
Lower French Broad
Middle French Broad

12. Stream Terms Channel – where the main flow of the river is found
Bank – the side of the river

13. Stream Terms Tributary – anything that empties into another stream
Base level – the lowest point to which a stream can erode its channel
Meander – bends/curves in a river/stream
Oxbow lake – a meander that gets cut off from the main stream and form a small lake.

14. Meanders and Oxbow Lake

15. Stream Erosion
The ability of stream to carry a load (sediment) is dependent upon 2 factors:
Competence - the largest particles the stream is transporting
Capacity – the maximum load it can carry

16. Sediment Transportation
3 types
Dissolved Load – sediment that is dissolved in the stream/river
Usually comes from groundwater
Suspended Load – the visible cloud of sediment a stream carries
Where a stream carries most of its load
Bed Load – sediments that are too large to be carried in suspension
Move along the stream/river bed

17. Stream Deposition
As the stream slows down material begins to settle out
Larger materials settle out first
Levee – accumulation of sediment along the river banks

18. Stream Deposition
Delta – a triangular accumulation of sediment formed where a stream enters a lake/ocean

19. Stream Depostion
Alluvial Fan – forms when a stream slows at the mouth of a mountain canyon

20. 3 Stages of Stream Development
Young
Mature
3. Old

22. Young Rivers fast straight narrow rapids v-shaped valleys

23. Mature Rivers slower meanders wider

24. Old Rivers slowest meanders and oxbows widest

25. Flooding Flood plain – flat areas along rivers that occasionally flood
Where sand and rocks are deposited on the side of the river
Things that increase flooding:
Paving
Excess precipitation
Vegetation Removal
Methods of flood control
Dams and levees
Limiting development

26. Ohio River Flooding

27. Drainage basin - the land area that contributes water to a stream
Divide – imaginary line that separates one drainage basin of one stream from another

28. Groundwater
Zone of saturation – area below ground where all the pore spaces are completely filled with water
Zone of aeration – all the pore spaces are not completely filled with water
Water table – the line that divides the two

29. Groundwater
Porosity – the percentage of the total volume of rock (or sediment) that consists of pore spaces
Permeability – how well water moves through the rock/sediment
Well rounded and well sorted grains = high porosity
Aquifer – rock layers or sediment that allow groundwater to flow freely (sandstone)

30. Groundwater
Springs – form whenever the water table intersects the surface of the ground
Hot springs – water is heated from magma just below the surface
Geysers – intermittent hot spring/fountain that periodically erupts (Old Faithful)

31. Groundwater Wells – a hole bored into the zone of saturation
A pump is needed
Cone of depression
Artesian wells – groundwater rises on its own under pressure and no pump is needed

33. Wastewater Treatment

34. Groundwater Environmental Problems
Overuse and contamination threatens groundwater supplies in some areas
Contamination
Fertilizers
Pesticides
Highway salts
Chemicals
Industrial wastes
Causes land subsidence with too much withdrawal

35. Land Subsidence

36. Groundwater Contamination

37. Caverns A naturally formed underground chamber
Usually forms in limestone from carbonic acid dissolving the rock
Dripstones
Travertine – Calcium carbonate deposits
Stalactites – form from the ceiling
Stalagmite – form on the floor and reach toward the ceiling

38. Stalactites and Stalagmites

39. Karst Topography
limestone areas with many caves and sinkholes (collapsed caves)

40. Sinkholes

41. Glaciers

42. Glaciers 10% of the Earth is covered in glaciers
Thick mass of ice that forms on land over hundreds or thousands of years

43. Glaciers Act like bulldozers while they move
Move rocks and sediments with them and keep them with them until they melt
Iceberg – a mass of ice floating the water
A piece of a glacier that has broken off
Only about 10% of it is above water

44. Erosion by Glaciers 5 types Glacial trough Hanging valley Cirque Arete
Horn
Striations

45. Glacial Trough
A “V-shaped” valley that has been eroded into a “U-shaped” valley

46. Hanging Valley
Valleys that are higher than the main glacial trough

47. Crique Bowl-shaped depression at the head of a glacial valley
Surrounded on 3 sides by steep rock walls

48. Arete
Sharp edged ridges left by glaciers

49. Horn
Sharp pyramid shaped peaks left by glaciers

50. Glacial Striations
Groves left in the rock when the glacier melts