| A | B |
|---|
| flood plain | a flat area that is found on both sides of a river or stream and is formed by sediments deposited during floods |
| erosion | the process by which the products of weathering are moved from one place to another |
| weathering | the breaking down of rocks and other materials at Earth's surface |
| tributary | a large stream or small river that flows into an area's main river |
| meander | a loop in a river |
| levee | in nature, a ridge-like deposit along the sides of a river |
| moraine | a ridge of till left behind a retreating glacier |
| till | the rock and debris deposited directly by a glacier |
| glacier | a large mass of moving ice and snow |
| alluvial fan | a fan-shaped deposit of sediments formed at the point where a river leaves the mountains and runs out onto a plain |
| delta | a triangular formation of sediments deposited at the mouth of a river that flows into a lake or ocean |
| oxbow lake | a U-shaped lake formed when erosion and deposition cuts off a meander of a river |
| contour line | a line on a topographic map that connects points of equal elevation |
| contour interval | the difference in elevation from one contour line to the next |
| topography | the shape of the land |
| relief | the difference in elevation between the highest and lowest parts of an area |
| mechanical weathering | the type of weathering in which rock is physically broken into smaller pieces |
| chemical weathering | the process that breaks down rock through chemical changes, like when water dissolves rock |
| headwaters | the many small streams that come together to at the source of a river |
| hypothesis | an educated guess |
| variable | any condition in an experiment that can change and might make a difference in the outcome of the experiment |
| experimental variable | the only variable allowed to change in a controlled experiment |
| controlled experiment | an experiment in which all variables are held constant except the experimental variable |
| control | a variable which is held constant (not allowed to change) in an experiment |
