Lakes and Rivers
Lakes are huge water bodies that hold a large amount of fresh water. Rivers are water bodies that flow according to gravity, usually ending at a larger body of water such as the sea or ocean.
Asked in Lakes and Rivers, Great White Sharks
Are there Great White Sharks in Lake Washington?
Asked in Lakes and Rivers
What is meant by water divide.give an example?
Asked in Rain and Flooding, Geography, Lakes and Rivers
Why does river straightening reduce flood risk?
Straightening of river reduces floods in the immediate area because it allows the water to go straight instead of having to turn through curves. A natural meandering river has a curvy or sinusoidal shape to its path. A straight river would travel only a kilometer per kilometer of valley floor. Water associated with a curvy river will have to follow the natural sinusoidal curves and will travel considerably more distance per kilometer of valley floor. Also, water in a natural river will have a slower velocity because the course of the river is altered with every curve. A straight river sheds water faster from the immediate area because it has less distance to travel and is not slowed by the curves, however the straightening a river is associated with negative consequences including increased risk of flooding downstream and increased erosion. Increasing the velocity causes more erosion. If a river is straight then erosion digs the river into a deeper and deeper channel. A curvy river is typically has a slower velocity and erodes less. Also the erosion in a curvy river is associated with the 'cut bank' or outside of each curve not with a deepening channel as seen in straightened rivers. If you imagine yourself as a water molecule traveling down the river when you arrive at the outside of a curve your inertia will cause you to run into the 'cut bank' until the outer bank slows your speed and alters your course. You may have caused a slight bit of erosion but because you keep hitting curves you can not build up the speed needed to induce much erosion. After eroding from the "cut bank" sediment is often deposited in the 'point bar' or inside of the next curve. This causes the curves to slowly meander sometimes leaving 'ox bows' or multiple channels. Building roads or structures in these meandering curves is unwise as inevitably erosion will destroy the structure. The fast moving waters of a straight river can carry far more sediments down stream because of the increased velocity. Straightened streams often had to be lined with concrete or 'rip rap' where the original curvy river did not because the high velocity induced severe deepening of streams and both banks would then collapse in. Straitened rivers increase the risk of flooding downstream. A straight river or stream holds less water per distance unit of valley floor than a natural and curvy river. In a rain event a natural curvy river will hold more water. Also, since it is not slowed by the curves of a natural river, a straight river will shed what little water it holds faster. This is exacerbated by the draining of wetlands upstream and the tiling of agricultural lands to shed standing water. Wetlands and intermittent pools act as large sponges, holding and delivering rain and snow-melt slowly to downstream rivers. Furthermore, the loss of flood planes by building levies causes rivers to rise higher during flood events and again delivers more water downstream in a short amount of time. Floods downstream have become more 'flashy' and acute because of straightening of rivers, building of levies and draining of wetlands. A rain event in the Midwest of North America prior to European settlement would have induced far less of a flood height down stream than the same rain event would cause today. This is because the water would be delivered to downstream locations slowly over a greater duration of time.
Asked in Science, Lakes and Rivers, Landforms
What is the worlds largest watershed?
According to Wikipedia, the three largest river basins/watersheds by area in descending order are: the Amazon basin, the Congo basin, and the Mississippi basin. However, if you list rivers by drainage area, you get: Amazon - 6,915000 km2 Río de la Plata - 4,144,000 km2 Congo - 3,680,000 km2 Nile - 3,349,000 km2 Ob - 2,990,000 km2 Mississippi - 2,980,000 km2
What are the capitals of the two states that border both the Mississippi and Ohio rivers?
Asked in South America, Lakes and Rivers, Amazon River
What is so special about Amazon River?
It is the second longest river in the world. As well as being the second longest river in the world, it has many roles, like watering many different diveristies of animals, from minor animals right up to the large animals such as the big cats of south america. It also has one of the largest spreads of area fed. Houses many different animals, such as the boto(amazon river dolphin), piranha, and some bull sharks. Also accounts for around one fifth the worlds river flow The Amazon river spans 3 countries...Brazil, Colombia, and Peru.
Asked in Lakes and Rivers, Definitions
What term describes a stream or small river that flows into a larger river?
A small freshwater river or stream flowing into a larger river is called a tributary or feeder river. A tributary is a stream or river that flows into a mainstem (or parent) river or a lake. For example, a tributary can be a creek that flows into a river. Or it can be a small river that flows into a larger river. A tributary does not flow directly into a sea or ocean. Some large rivers can have up to 100 tributaries. The spot where the smaller and larger river meet is called a "confluence". In contrast, a body of water that branches off and flows away from the main river is called a distributary.