The materials presented here highlight the fact that Earth's supply of water is finite and is constantly recycled. We depend on water for drinking, washing, recreation, agriculture and industry. It controls the world's weather and sustains the natural systems above and below the earth's surface. Users can examine an illustration that shows the role played by groundwater in the hydrologic cycle and ... Full description.

In this activity, students build a model illustrating the water cycle, and observe the results. The site includes a materials list, instructions, and information about the water cycle. A downloadable version is available, and the activity is also available in Spanish. Full description.

In this activity, younger students enact the process by which precipitation (rain, snow, and hail) falls on an area and becomes standing water, run-off, or groundwater. They will learn general information about precipitation processes, aquifers, and the importance of clean groundwater. Full description.

This interactive tour of the water cycle allows students to follow a water molecule from a home's plumbing system as it follows different routes through the hydrologic cycle. Students learn about how water is used, treated, and returned to the natural environment where it can cycle through liquid, solid, and gas phases. Full description.

This site uses a picture of a covered swimming pool as an example of a watershed and describes real-world watersheds and their processes, including precipitation, infiltration, evaporation, transpiration, and storage. Links to an interactive rainfall calculator and to related websites are included. Full description.

This site provides a discussion of the downward movement, or infiltration, of water from the surface into soil or porous rock. Graphics illustrate the processes affecting infiltration, including precipitation, soil characteristics and saturation, land cover, slope, and evapotranspiration. Links to additional sources of information are also provided. Full description.

This United States Geological Survey site focuses on water and its properties. The site contains activities for teachers and students, along with pictures, data, maps, and an interactive center where users can give opinions and test their water knowledge. Unique aspects of this site include the sections that contain student work and a picture gallery. There are links to other resources for students, ... Full description.

This live, interactive electronic field trip to a North Carolina estuary is conducted on two dates each year. Previous field trips are stored for non-interactive access. Teachers can access resources on such topics as estuarine and coastal monitoring, management, cultural traditions, invasive species, and habitat restoration. The lesson plans include grade level and standards applicable for technology, ... Full description.

Students participate in two interactive exercises designed to help the user learn about river processes like discharge, flooding, and flood frequency. Each activity requires a person to make careful observations and measurements, do simple calculations, and answer questions about his or her work. A Certificate of Completion is available for printing at the end of each activity. Full description.

This activity prepares you to launch an investigation of the relationship between precipitation and streamflow for a local watershed. It can enrich a study of the water cycle. Following the step-by-step instructions in a case study you will locate, download, format, and finally graph one year of Web-based data for these two variables. The graph highlights the details of this often complex precipitation-streamflow ... Full description.