Presentation on theme: "Streams. Major US Rivers A drainage basin a.k.a. watershed is the area of land that drains to a particular lake, wetland or ocean."— Presentation transcript:
Major US Rivers
A drainage basin a.k.a. watershed is the area of land that drains to a particular lake, wetland or ocean.
Where do rivers and streams get their water from? 3 sources
From its source to the Sea A stream begins at its headwaters, often in areas where there is constant runoff of rain or melting snow or an underground spring. The stream continues to flow and combines with other streams (called tributaries) until they become a river system The river will flow until its mouth (the end of the river) opens into the ocean, lake or sea The mouth of a river creates a Delta (a layer of sediment)
What is a Stream Erosion? Stream erosion is the transportation of weathered material collected in the stream
Parts of a River Channel Bank (outside of a river) Bar (inside of a river) Bed (bottom of a river)
Youthful Steep gradient Rapids and waterfalls Stream course is straight No or very little drainage basin (the area of land that surrounds and include the major river and all of its tributaries.
Mature Weathering and erosional effects have made the land wider and flatter Speed of river is reduced Starting to get curvy (meanders) Drainage basin are forming and more tributaries are joining
MEANDER Meander – a curve or bend in the river
Old Extreme meanders are present Land around it is very flat Speed is super slow Large drainage basin Oxbow lakes
NAME THE STAGE
Summary Question A Changing River 200 years ago a stream was set as a boundary on some land. Now surveys show that this river is no longer used as an accurate boundary. Why?