| INTRODUCTION: We have already used many words to describe rivers or geographic features about them, but there are others we need to know as well. In the following list, look at each term and be sure you understand it.
| 1. Current & course. Rivers always flow downward, never up! They follow a course that leads them lower and lower no matter how winding it may be. The flow of water in the river is its current. When a river drops rapidly, what happens to the current? |
| 2. Rapids, falls, & cascades. Swiftly moving water is likely wherever a river drops rapidly as down a mountain slope. The steeper the slope, the more swift the current. If it is not too deep, a river moving over a rocky bed will churn and boil as it makes its way over and around the rocks. This produces rapids. When such a river flows over a cliff we know it as a waterfall, but when it drops over a series of smaller falls or over a long section of rapids, we may call it a cascade. Where are we most likely to find waterfalls? |
| 3. Creek & stream. Rivers vary in size. Very small ones are streams and creeks. A creek is often just a trickle of water through a field. If you can, name a river, stream, and creek in your area. |
| 4. Swamps, marshes, & bayous. Where the land is flat, water moves very, very slowly. There may be no apparent current. It soaks the ground. We may think of very wet soil as marsh. Where shallow water covers the soggy land, we have a swamp. Some of the very slow moving streams in swamplands near the Gulf of Mexico are called bayous. What would you worry about if you were boating on a bayou? |
| 5. Oceans, seas, & lakes. East and west of America are two giant oceans. They are the biggest bodies of water on earth. But inland there are bodies of water too. Seas and lakes are places where water collects. Usually they are just steps on the path of rivers to the ocean. But some are "salt lakes" or "salt seas" that have no river out! They may even be below the level of the oceans. There is one like this in California called the "Salton Sea." Rivers too may move underground. They may even sink into the soil only to reappear at another point. California's Mojave and Nevada's Humboldt are examples of such rivers. What ocean, sea, or lake does your nearest river flow into? |
| 6. Dams, reservoirs, & aquifers. By building a dam across a river, we can create our own lake. We call this a reservoir because it stores water for other uses. It can also help control flooding. But there's a special kind of reservoir nature makes. We call it an aquifer. This is a large pool of water under the ground in which water collects but cannot be seen. Often it comes up somewhere else in springs. Sometimes the source of a river is a spring or spring-fed lake. If you can, name a spring or spring-fed lake. How else can we get water from aquifers? |
| 7. Fords and ferries. Often we need to cross rivers. Today we usually use bridges or tunnels, but in pioneer times we often used a ferry to carry us and our goods across the river or walked through the river at a shallow point called a ford. What would you worry about if you had to ford a river? |
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