River Systems 10/8/15

Glacial Melt (the source)

Spring (another source) Water that comes to the surface from underground (often starts in the mountains)

Stream Body of water with a current.

Tributary A contributory stream, or a stream which does not reach the sea but joins another river.

Lake Water without a current surrounded by land.

Waterfall & rapids Waterfall – permanent flow of water over an erosion-resistant cliff. Rapids – part of a river where current is very FAST and rough (can often be found at the bottom of a waterfall).

Meandering River Only one channel that winds its way across the floodplain. As it flows, it deposits sediment on banks that lie on the insides of curves, and erode the banks on the outside of curves.

Oxbow Lake A crescent-shaped lake lying alongside a winding river. The oxbow lake is created over time as erosion and deposits of soil change the river's course. You can see how an oxbow lake is formed in the pictures on the next page.

On the inside of the loop, the river travels more slowly leading to deposition of silt.

Meanwhile water on the outside edges tends to flow faster, which erodes the banks making the meander even wider.

Over time the loop of the meander widens until the neck vanishes altogether. Then the meander is removed from the river's current and the horseshoe shaped oxbow lake is formed.

Alluvial Fan Alluvial fans are fan-shaped deposits of water- transported material (alluvium)

River Delta A landform that forms at the mouth of a river, where the river flows into an ocean, sea, estuary, lake, or reservoir. Deltas form from deposition of sediment carried by a river as the flow leaves its mouth.