Science Chapter 16 : Surface Waters
Oxbow lake
This is produced when a meander gets cut off from the main flow of a stream.
Flow in by an inlet stream, fall as precipitation, come from an underground spring, filled by meltwater from glaciers
What are 3 possible sources for water that is found in a lake?
Some advantages include: they are non-polluting, renewable, they control flooding downstream, they reduce soil erosion, and the water can either be used for drinking or other activities.
What are some of the advantages of building dams to produce hydroelectric energy?
Lakes can: -moderate the weather -provide transportation routes -can be used for recreation -can be uses for agricultural uses -provides drinking water -provides water for power production\ -provides water for industry
What are some ways lakes affect man?
Tributaries
What do we call a smaller steam that feeds a larger stream?
Headwaters or source
What do we call the ORIGIN of a stream?
Base level
What do we call the lowest level to which a stream can erode?
Stream
What do we call water that flows either seasonally or continuously on a distinct course over land?
Drainage Basins
What geographical feature describes the area drained by a stream system?
They shrink
What happens to most lakes in the natural course of events, over time?
An increase of nutrients in a body of water. It causes 'blooms' of algae and bacteria, reduces oxygen levels, increases turbidity, and can ultimately change what organisms can live in that water.
What is Eutrophication?
Movements in a lake or pond which is like sloshing. This is caused by changes in air pressure due to weather. They can change surface height by up to several meters.
What is a seiche?
It is the description of how the stream changes from its beginning to its end.
What is an elevation profile?
The mouth (this is also where it flows into another body of water.)
What is the lowest point to which a stream flows?
Lake superior
What is the world's largest freshwater lake in area?
Lake Baikal(located in Russia)
What is the world's largest freshwater lake in volume?
Volcanic craters (caldera), meteor craters, sinkholes, basins
What sort of naturally occurring geographic features can turn into a lake?
Low-gradient
Which gradient stream has flood plains?
High-gradient
Which gradient stream has rapids and waterfalls?
The flooding that occurs in the flood plains creates excellent topsoil which is abundant with minerals. This creates great conditions for farmers to plant their crops.
Why are floodplains good areas for farming?
They have inlets but no outlets. As a result, dissolved minerals are brought in and as the water evaporates from the surface, the mineral concentrations increase, thus making the lakes saltier.
Why are the Great Salt Lake and the Dead Sea so salty?
To control flooding and protect property. (A levee is a wall along the channel of the river to contain the river to the channel.)
Why would an engineer design a levee?
Cross section
A crosswise view of a stream
Stream System
A stream along with all of its tributaries is called what?
Floodplain
Broad, fertile topsoil deposits from the flooding of a stream.
In a high-gradient stream, the rate of erosion will be high, but will have the least amount of deposition occurring. Low-gradient streams have the most deposition and least erosion.
Describe how a stream's rates of erosion and deposition are related to its gradient.
Low gradient, because they have had longer to erode the soil down to the base level. Older streams will have lower gradient as they have had longer to erode
Do 'older streams' have high or low gradient?
Erosion occurs more quickly on the outside curve of the meander, because of the higher rate of flow. Materials are deposited more on the inside of the meander. This moves the stream toward the outside edge.
Explain how a stream's meander can move sideways across the land.
In lakes and ponds
Generally speaking, where can we find the greatest amount of the earth's fresh surface water?
A low-gradient stream that suddenly flows over the edge of an eroded rock can quickly become a high gradient stream when it flows to a lower level. Example: Niagara Falls
How can a low-gradient stream suddenly develop into a high-gradient stream as it runs its course?
A small V shaped stream. They tend to be fast flowing because they are V shaped.
How would you describe the shape of a high gradient stream?
An intermittent stream. (This is a stream that is sometimes there and other time dry.)
If you look at a topographic map and see a dotted blue line, what sort of stream is that indicating?
Limnologist
Scientist who studies lakes
Stream gradient
Steepness of the stream's channel
Elevation profile
The gradient of a stream relates to its what?
Drainage basin
The land a stream drains
Gradient
The measure of the slope of a stream is its______
Limnology
The study of lakes and freshwater systems
Meanders
These develop in the channels of low-gradient streams as they erode the sides of the riverbed.
