Chp. 9.1 & 9.2 Notes

Surface Water Movement & Streams

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Today:1. 9.1 & 9.2 Notes2. Book assign, page 221 #1-6

WATER ON EARTH IS IN CONSTANT MOVEMENTOR IS TEMPORARILY BEING STORED, SUCH AS IN CLOUDS, LAKES, OCEANS, GLACIERS.

Main Idea

Describe: Rain, snow, hail, or water that forms via the condensation of water vapor in the atmosphere, then it falls to earth.

Precipitation

Define: The evaporation of water from plants & the soil into the atmosphere.

Evapotranspiration

Define: Process by which plants release water vapor from their leaves.

Transpiration

Define: process by which a liquid become a gas.

Evaporation

Freshwater contains less than 1% dissolved salts & it can be found in standing or moving water.

Main Idea 2

Describe: The water sources (springs, lakes, or runoff) from which a river FIRST starts.

As water flows downhill:-It flows w/ gravity, picks up speed, sediment, more water

The bottom wears away as rocks move along.

PARTS OF A River

Head Water

Mouth: where a river empties into another body of water, such as lake or the ocean.

YOUNG RIVERSMovement speed: fast

Type of material carried: large rocks (called bed load)

Number of tributaries: few

Number of meanders: few

The Life of a river!

Movement speed: slower

Type of material carried: smaller rocks (suspended load)

Number of tributaries: many

Number of meanders: more

Mature Rivers

Describe formation: At meanders, rivers flows faster along the river’s banks & slower in the middle.

--The river banks get eroded into mud & sand.--Mud & sand get deposited on the inside banks & creates meanders. --Eventually, main channel gets cutt off; forms a U-shaped lake.

Oxbow lakes

Movement speed: slow!!

Type of material carried: sand and mud

Number of tributaries: fewer, but has a wider floodplain

Number of meanders: many!!

Old rivers YOUNG RIVER

MATURE

Floods can bring rich, fertile soil or devastation!!!!!

Main idea #3

Fertile soil

Delta FORMATION

Define: A delta is alluvial deposits at the mouth of a river.

Describe: As bodies of water slow down, they deposit silt, sand, or gravel.

Results of flooding

Define: Any land area near a river that can get covered w/ water during a flood. They often have very fertile soils used for crop lands.

Describe: As precipitation input exceeds the limit of the stream’s banks, water spills over the sides & onto adjacent land.

Floodplains often end up w/ sediment, garbage, & destroyed homes.

Flood plain

Prevention Methods:Levee: An elongated dike or bank that is natural or is man-made from rock/gravel fill or as a wall.

It helps regulates levels of nearby water bodies.

Devastation

Sandbags: Stack these along banks or across a stream to reduce erosion, slow down

or divert a stream.

More Devastation Prevention

Flood Dam: This impounds excess water as alake or pond so it can be absorbed by soils &plants or it can evaporate faster of a larger surface.

Devastation Prevention #3

Main Idea #4

A river is not an isolated entity! Many square miles of land interact & are influenced along the slopes & drainage areas of a river.

Define: Watershed is the land area drained by a stream.

Pollution Problems: Logging roads can directly add noticable sediments to a stream (called point-source).

A cluster of farms can release so many wastes into streams that you can’t pin-point exactly which one (non-point).

Watershed