The USGS explains the definition of a river and how a river is supplied with water. Included is a cross section of a river. Click Home to access the site in Spanish.

Make Earth's climate livable by adding the right amount of air, water, and clouds to its surface and atmosphere.

Groundwater is one of the largest sources of drinking water, so environmental engineers need to understand groundwater flow in order to tap into this important resource. Environmental engineers also study groundwater to predict where...

An air mass forms when the air over a large region of Earth sits in one place for many days. The air gradually takes on the characteristics of the land or water below it. Where Earth's surface is cold, the air becomes cold. Where Earth's...

Science Bob presents instructions for a science demonstration of how to build a soap-powered model boat using common supplies with information on how it works.