Rivers and Waterways
Water Cycle and Weather
Terrain and Geology
Features and Materials
100

The point where two or more rivers meet and flow together.

confluence

100

The continuous movement of water on, above, and below the surface of the Earth.

hydrological cycle

100

A large rock, typically one that has been worn smooth by erosion.

boulder

100

Water held underground in the soil or in pores and crevices in rock.

groundwater

200

A loop-like bend or winding curve in the course of a river.

delta

200

The conversion of a vapor or gas to a liquid, such as water vapor turning into clouds.

condensation

200

A steep, high face of rock, especially at the edge of the sea.

cliff

200

A property of a material or rock layer that does not allow fluid to pass through it.

impermeable

300

A winding curve or bend in a river, caused by lateral erosion.

meander

300

Pellets of frozen rain which fall in showers from cumulonimbus clouds.

hail

300

Soft, finely stratified sedimentary rock that formed from consolidated mud or clay and can be split easily into fragile slabs.

shale

300

Soil or land capable of producing abundant vegetation or crops.

fertile

400

The tidal mouth of a large river, where the tide meets the stream.

estuary

400

Rain, snow, sleet, or hail that falls to the ground.

precipitation

400

A narrow valley between hills or mountains, typically with steep rocky walls and a stream running through it.

gorge

400

To make something impure or dangerous by exposure to or addition of a poisonous or polluting substance.

contaminate

500

An area or ridge of land that separates waters flowing to different rivers, basins, or seas.

watershed

500

The process of water movement through a plant and its evaporation from aerial parts, such as leaves.

transpiration

500

The sliding down of a mass of earth or rock from a mountain or cliff.

landslide

500

A rough fiber used for making sacks, rope, and coarse fabrics, obtained from a tropical plant.

jute