1. Unit 6 Topic 8 in your Review Book
Hydrology
Unit 6
Topic 8 in your Review Book

2. Hydrology is the study of water in, on and around the earth
The water cycle
a model of the movement and changes in phase of water at and near the surface of the earth

3. Evapotranspiration:
A combination of:
the evaporation of surface and ground water and
the release of water vapor through the pores of leaves
It is the source of all atmospheric water vapor

4. Precipitation:
the source of water for the earth
in the form of rain, drizzle, snow, sleet, freezing rain and/or hail

5. 3. Water and Climate
Climate is the overall view of a region’s weather conditions over a long period of time
The two factors tied to climate are:
Temperature
Moisture

6. Potential evapotranspiration is the amount of water vapor that would occur in an area if the water was available.
It is mostly determined by the amount of insolation an area receives (which determines the regions’ average temperature)

7. When
PPT < ET: the climate is arid or dry
PPT > ET: the climate is humid or wet

9. Storage:
ground and surface waters
Surplus:
excess water
Deficit:
not enough water

10. A. Factors influencing climate
Latitude:
as latitude increases,
temperature decreases
Planetary wind and pressure belt: see ESRT page 14

11. Oceans and other large bodies of water
Mountains
Elevation
Cloud cover
Vegetation

12. Concepts of the Water Cycle
A. Infiltration:
the process by which water soaks into the ground under the influence of gravity
The water table is the limit of infiltration

13. If the ground is saturated (holding all of the water it can hold) infiltration cannot occur
If the ground is frozen, infiltration will not occur
If the precipitation is rapid and/or intense, infiltration is less likely to occur

14. If the slope is steep, infiltration is less likely to occur
If the ground is covered with pavement and/or buildings, infiltration is not likely to occur
If the soil is impermeable, infiltration cannot occur

15. Permeable soil or sediment allows water to flow down through it.
Porosity is the ability of a material to hold water in open spaces
Porosity depends upon the interconnectedness of the spaces between the sediment

16. Well-sorted sediments with round grains have a high porosity
Size does not affect porosity
Shape and sorting does!
Porous sediment is very permeable

17. As porosity increases
permeability increases
As degree of sorting increases
porosity increases and
As roundness increases

18. B. Water Table
The interface between the zone of aeration and the zone of saturation
Its depth fluctuates and is dependent upon the amount of available moisture

19. At times of moisture surplus
the water table is located closer to the surface…
the depth of the water table decreases

20. At times of moisture deficit:
the water table is located farther from the surface…
the depth of the water table increases

22. Zone of saturation Normal depth Deficit depth Surplus depth
Z of A
Zone of aeration
Zone of saturation

23. The end!