landform
A natural shape of Earth's surface, such as a mountain, plateau, plain or valley.
tectonic plate
A giant, slowly moving slab of Earth's crust and upper mantle.
erosion
The carrying away of rock and soil by water, wind, ice or gravity.
contour line
A map line joining points of the same elevation.
drainage basin
All the land that drains into one river, lake or ocean.
climate
The usual pattern of weather in a place over many years.
natural vegetation
The plants that would grow in a place if people had not changed it.
sustainable
Meeting needs today without harming future generations' ability to meet theirs.