What are landforms? <ul><li>A landform is a shape or feature of the earth’s surface. There are many, many landforms. </li></ul><ul><li>Mountains, valleys, plains, and canyons are examples of some major landforms. </li></ul><ul><li>Landforms affect how and where people live. </li></ul>
Erosion A river or stream moving over the surface of the earth can erode or wear away earth materials. This process is called erosion . A system of rivers and streams that drain an area is called a drainage basin.
The water source placed over this stream tables represents a river flowing over a plateau . A plateau is a large, nearly level area that has been lifted above the surrounding area. What do you notice about the edge of the cliff ?
Floodplains Large areas of this plateau are saturated with water. This is called a floodplain .
Channels and Meanders The blue dye helps show how the water moves over the surface of the earth materials. The course or path the river takes is called its channel The curves or loops in its path are called meanders.
Can you see the main channel that is forming? Can you find the meanders?
What are the v-shaped valleys seen in this photo? How were they formed? Those v-shaped valleys are canyons. Canyons are formed by erosion.
What is the fan shaped landform that has formed at the mouth of this river? Where did the earth material to make this landform come from? The fan shaped landform is a delta. It has been formed by eroded earth materials that have been deposited at the mouth of the river. Can you see why this process is called “deposition ”?
Deposition In these images you can see that most of the sand is settling out near the mouth of the river. The clay is being moved and deposited further downstream. Why do some particles travel further than others?
Deposition The large deltas shown in these stream tables are the result of deposition. Eroded earth materials were carried by the moving water and deposited in layers at the mouth of the river. The heavier materials (the sand) settle out first. The lighter materials (clay) are carried further by the moving water. Can you see the clay in the water in these 2 stream tables? It looks like cloudy water.
Sediments and Basins In this image you can see the that erosion is just beginning. The earth material is beginning to settle in a low area, the basin . The earth materials that have been eroded and are being deposited are called sediments . As more materials is eroded and moved downstream it will build up in layers.
Canyons and Deltas Canyons and deltas can be easily seen in this stream table. What is a canyon? What is a delta? Canyons are formed by e… Erosion! Deltas are formed by d… Deposition!
Enjoy these beautiful photos of slides and canyons