Surface Water- Chapter 6

6.1 THE WATER CYCLE

The Hydrologic Cycle(a.k.a. “Water Cycle”) is the unending circulation of Earth’s water supply.

Label the following processes on the diagram and define them below:

Evaporation-

Condensation-

Runoff-

Infiltration-

(Evapo)Transpiration-

Precipitation-

6.1 RUNNING WATER

-Tributary-

-River System-

-Drainage Basin-

-Divide- (example: Rocky Mountains)

Characteristics

  1. Velocity-

-Related to the amount of energy that the water has

-Erosion occurs more quickly

-Other characteristics affect the velocity

  1. Gradient-

-steep at its ______; gradual at ______

  1. Discharge-

-not constant over length of the river because:

  1. Channel-

-shallow, winding stream with many boulders has contact with surface area that causes it to ______by friction

-straight channel that is wide and deep has less surface area in contact with water, so ______

6.2 THE WORK OF STREAMS

Erosion-

-running water ______

-breaks up materials by mechanical means (does not change chemical composition)

  • abrasion mainly; in time, creates rounded boulders, pebbles, and sand grains

Deposition-

-occurs because:

Erosional Features

-Potholes & Plunge Pools

Depositional Features

-Delta-

  • River water comes to almost a standstill here
  • Distributaries-
  • Formation is a delicate balance between deposition and erosion

MEANDERS = ______

Notes about diagram:

Erosion likely to take place:

Deposition likely to take place:

Floods

-most caused by ______or ______

  • example: Mississippi River in 1993


Measures to control flooding:

  • Artificial levees-
  • Flood-control dam-
  • Limits on floodplain development-

6.3 Water Beneath the Surface

- Much of the water in soil seeps downward until it reaches the zone of saturation.

-Where is groundwater located?

Zone of Saturation:

Water Table:

Zone of Aeration:

Water Movement

Porosity-

Permeability-

Aquitards-

Aquifers-

Springs

-A flow of groundwater that emerges naturally at the ground surface

-How it forms:

Wells

-Hole bored into the ______

  • Irrigation for ______
  • ______Use
  • Home Use

-Cone of depression-

-Artesian Well- groundwater rises on its own under pressure because it’s trapped below an aquitard (or impermeable layer)

Karst Topography-

-typically have irregular terrain, with many depressions

  • sinkholes-
  • form in one of two ways:
  • ______develop; fairly shallow and have gentle slopes
  • Form when ______collapses; steep- sided and deep

Environmental Problems and Human Impact:

-Overuse and contamination threatens groundwater supplies in some areas

  • Aquifer Depletion
  • Subsidence:
  • Saltwater Intrusion:

Name Some Sources of Groundwater Contamination:

Misc. Water Information:

- Groundwater is considered nonrenewable

- Potable: water fit for drinking

- Negative resource problems: less resources available+ increased human population = resource degradation

Two main types of freshwater pollution

1. ______Source: Pollution that comes from a ______and specific location

EX.

2. ______: does not have a specific point of ______

EX.

Eutrophication

- Nutrients enter surface water & too many nutrients cause environmental problems

- Large amounts of ______& ______promote runaway growth of algae

- Open water is choked with plant growth.

- Plants ______– increase in the # of decomposing ______

-Oxygen in water______

What are the five steps to the problem of Eutrophication?

EPA Virtual Tour – Drinking Water Treatment Plant

SOURCE WATER AND INTAKE

What are potential threats to surface and ground water quality?

PRETREATMENT AND SCREENING

What do screens do?

What is aeration?

What does aeration do?

What other chemicals can be added? What do these chemicals prevent?

COAGULATION AND FLOCCULATION

What does alum do?

After floc has formed, what occurs next?

What law was passed to ensure drinking water is safe for human consumption?

SEDIMENTATION

What happens during this process?

How can sludge be used/disposed of after it is filtered from the water?

FILTRATION

What do filter beds contain?

What does filtration reduce in the water?

DISINFECTION

Why is this process important?

What is one problem with disinfectants?

DISTRIBUTION AND STORAGE

What does a cross-connection do?

Where are water towers always placed? Why?