Warm-up What are four things that impact INFILTRATION? (the answer is in your notes) After you finish the warm-up put your river basin project in the inbox.

Rivers TOMORROW IS THE LAST DAY FOR TEST CORRECTIONS! Reminders: Quiz on chapter 9 TOMORROW Chapter 9 study guide due tomorrow TOMORROW IS THE LAST DAY FOR TEST CORRECTIONS!

4 things that impact infiltration Vegetation – slows down runoff Rate of Precipitation – time to soak Soil Composition – large enough pores (spaces) with room for water Slope – erosion on steeper slopes

Rivers Stream banks – the sides of the stream A channel is the path that a stream follows. When the channel becomes wider and deeper due to erosion, rivers eventually form. Stream banks – the sides of the stream

Rivers Gradient- is the measure of the change in elevation over a certain distance. Gradient effects erosion rates

Tributary- a stream that flows into a lake or into a larger stream.

The River Mouth Where the river meets the ocean or another large body of water

Stream Formation Headwaters – where water first accumulates to supply a stream Headwater erosion – process by which streams erode at the head of a stream

Meandering Streams When water begins to erode the sides of the channel, adding bends to the river. A bend or curve in a stream channel caused by moving water is called a meander.

Oxbow Lake Blocked off meander Eventually dries up

Discharge- The amount of water that a stream or river carries in a given amount of time Load- The material carried by a stream or river is called its load. Fast moving streams or rivers carry larger particles and slower moving streams carry smaller particles

Which river would be able to carry larger particles?

DELTA A river’s current slows when a river empties into a large body of water, such as a lake or an ocean As its current slows, a river often deposits its load in a fan-shaped pattern called a delta

Alluvial Fan When a fast-moving mountain stream flows onto a flat plain, the stream slows down very quickly As the stream slows down, it deposits sediment The sediment forms an alluvial fan Unlike deltas, alluvial fans form on dry land

Floodplain Low, flat lands adjacent to water that periodically floods

The area along a river that forms from sediment deposited when a river overflows its bank is called a floodplain Floodplains are rich farming areas because periodic flooding brings new soil to the land Floods can damage property and cause a loss of lives

Stream Load All the materials that the water in a stream carries Microscopic life forms Plants Fish Sediments Dissolved solids Dissolved gases

Bed Load Sediments too heavy to remain in water suspension settle to the bottom of the stream or basin The bed load is the settled sand, pebbles, and cobbles (larger stones) that get pushed around on the stream bed (bottom), but are no longer in suspension

Streams Carrying Capacity The ability of a stream to transport material Depends upon velocity and volume – the greater the volume, the more it can carry Also depends upon slippery, steep, narrow sides or tapering, sandy, wide sides

Stream Load vs. Bed Load Stream Load contains dissolved material in solution and particles in suspension. Bed Load particles roll along the bottom.

Calculating Stream Discharge Measure of the volume of stream water that flows over a particular location within a given period of time Discharge (m3/s) = width X depth X velocity

Discharge Calculation For a stream with velocity of 10 meters per second, a width of 5 meters and a depth of 10 meters, what would its discharge be?

What is the discharge of a stream that has a velocity of 100 meters per second, a density of 1.2 g/ml, a depth of 10 meters, a width of 20 meters and a temperature of 20o C?

Stream Discharge Mississippi’s discharge = 173,600 m3/s Amazon River discharge over 1,000,000 m3/s! What might change a river’s discharge?