“Where’s Water?” Unit: Surface Water
Rivers, Lakes, and Ponds

River Systems
 The streams and smaller rivers that feed into a main river are called tributaries
 Tributaries flow downward toward the main river, pulled by the force of gravity
 A river and all its tributaries together make up a river system

 Headwaters
 Tributaries
 Flood plain
 Oxbow lake
 Meander
 Mouth
 Delta
 Estuary
River Features

River Features
 The many small streams that come together at the source (beginning) of a river are called its headwaters
 The steep slope of the land causes the river to flow quickly

River Features
 Meanders -looping curves in a river
 Meanders can curve back on themselves.
The river may then cut a new, straight course, eventually leaving an oxbow lake

Horseshoe
Bend of the Colorado River near Page, AZ

Ox Bow lake on Mississippi

River Features
 The broad, flat valley through which a river flows is its flood plain

River Features
 The mouth of a river is where the river flows into another body of water
 A delta is created when the river slows down and deposits the sediment it was carrying

Delta Formation
DEPOSITON OF MATERIAL BY THE RIVER
WHEN IT ENTERS THE SEA

Mississippi Delta from Space
MISSISSIPPI

Watersheds
 The land area that supplies water to a river system is called a watershed
 Watersheds are sometimes known as drainage basins
 We live in the Delaware River Watershed

Divides
 A ridge of land that separates one watershed from another is called a divide
 Mountains are an example of a divide

Divides

Estuaries
 An estuary is a coastal inlet or bay where fresh water from rivers mix with salty ocean water

River Features Practice

Place a box around a tributary of the Mississippi River

Identify a tributary of a tributary of the Mississippi River

Put a X around the Headwaters of the Mississippi River

Circle a meander of the
Mississippi River

Circle an Oxbow Lake along the Mississippi River

Name a state that is in the flood plain of the Mississippi River

Put a star at the mouth of the
Mississippi River

Put a star at the mouth of the
Missouri River

Put a star at the mouth of the
Ohio River

Shade in an area of the
Mississippi River Watershed

Identify a divide of the
Mississippi River Watershed

Mississippi River Features
 What is this land formation at the mouth of the Mississippi
River called?
 The fresh water of the
Mississippi River mixes with the salt water of the Gulf of
Mexico and enters the
Atlantic Ocean. What is the term for fresh water mixing with salt water?

Surface Water Part II:
Ponds and Lakes

 Ponds are freshwater
 Ponds are shallow
 Ponds form when water collects in low-lying areas of land
 Plants grow at the bottom of ponds
Ponds

Lakes
 Lakes are freshwater
 Lakes are deep
 Lakes form when water collects in low-lying areas of land
 Plants do not grow at the bottom of deep lakes
Lake Baikal, Russia

Lake Formation
 Lakes can be formed by natural processes or human efforts:
 1. Volcanic lakes
 2. Glaciermade lakes
 3. Humanmade lakes
 A lake that stores water for human use is called a reservoir

Volcanic Lake

Glacier-Made Lakes

Human-Made Lakes

Lakes Can Change
 Seasonal changeswater temperature at different depths changes during the year
 Lake turnover-nutrients mix
 Nutrients -substances such as nitrogen and phosphorous that plants and algae grow

Lakes Can Change
 Long-term changes
 EutrophicationAlgae and scum forms on the surface of the water
 becomes so thick that it blocks out sunlight and plants cannot carry out photosynthesis
 Death of a body of fresh water

Eutrophication

Eutrophication

Ponds and Lakes
SAME
 Freshwater
 Still, standing water
 Form when water collects in hollows and low-lying areas of land
DIFFERENT


Lakes are deeper
Plants don’t grow at the bottom of deep lakes
 Sunlight cannot reach the bottom of a deep lake and photosynthesis cannot occur

Crater Lake and Lake Nyos Links
 http://en.wikipedia.org/wiki/Crater_lake
 http://news.bbc.co.uk/onthisday/hi/dates/sto ries/august/21/newsid_3380000/3380803.st
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