| A | B |
|---|
| groundwater | water beneath Earth's surface |
| channel | deepest part of a river or other body of water |
| source | place where a river begins |
| mouth | place where a river empties into a larger body of water |
| tributary | a stream or river that flows into a larger stream or river |
| river system | a river and its tributaries |
| drainage basin | the land drained by a river system |
| erosion | the gradual waring away of Earth's surface |
| floodplain | the low, flat land along a river |
| delta | the triangle or fan shaped land at a river's mouth |
| precipitation | any form of water, such as rain, sleet, or snow, that falls to Earth's surface |
| climate | the kind of weather a place has over a long time |
| humidity | the amount of moisture in the air |
