Sandboxes have come a long way. A new interactive, augmented-reality exhibit brings watersheds to life at the University of California, Davis’ Tahoe Science Center in Incline Village, Nev.

Participants run their hands through real sand, forming mountains, lakes and rivers, while a 3-D camera and digital projector allow users to create virtual topography in real time, make it “rain” and watch where the water flows.

More than just a high-tech take on a playground icon, the “Shaping Watersheds Interactive Sandbox” shows in living color how water moves and interacts with the landscape to create watersheds.

For example, a participant’s hand, held above the sand, casts a shadow, causing blue virtual rain to fall from a virtual cloud. And, if a person carved a river in the sand and built a dam, the rain would fall on the river and flow until the dam stopped it.

“It’s a teaching tool for all ages,” said UC Davis Tahoe Environmental Research Center director Geoffrey Schladow. “Usually, when you talk to kids about topography or what a contour line means, they’re asleep in 30 seconds. With this exhibit, they’re playing around, seeing the topographic map and watching how water flows downhill and where it goes. It becomes a game, and they’ve done it without really knowing they’ve learned something.”

The exhibit is one of four such educational sandboxes created by the UC Davis Tahoe Environmental Research Center and the UC Davis W.M. Keck Center for Active Visualization in the Earth Sciences (KeckCAVES) as part of the National Science Foundation-funded LakeViz3D project. The first prototype is on the UC Davis campus, and the other interactive sandboxes are at partnering institutions, the UC Berkeley Lawrence Hall of Science and the ECHO Lake Aquarium and Science Center in Vermont.

The interactive sandbox was inspired by a video created by a group of Czech researchers, who demonstrated in 2011 a prototype of an augmented reality sandbox that used color mapping and a limited form of fluid flow.

A UC Davis team, led by KeckCAVES associate research scientist Oliver Kreylos, took the basic idea of capturing a sand surface with a 3-D camera -- a Microsoft Xbox Kinect, in this case -- and projecting a colored image depicting elevation back onto the sand. They added a realistic water simulation, as well as elevation contour lines to make the sandbox look more like a printed topographic map.

“I think the interactivity combined with the technology is really compelling,” said Louise Kellogg, KeckCAVES director and geophysics professor in the UC Davis Department of Geology. ”The sandbox is best suited for education and outreach. But augmented reality has a lot of potential for all sorts of applications. I don’t think we’ve fully tapped its potential.”

The sandbox exhibit can demonstrate concepts that affect water-quality management, geology and hydrology, such as flood control, dam construction and stormwater runoff.

“Some of the issues that concern Lake Tahoe -- like the idea of urban water moving quickly over roads, picking up sediments and entering the lake -- can be demonstrated with this,” said TERC education and outreach director Heather Segale.

The exhibit “Shaping Watersheds Interactive Sandbox” joins a research vessel, laboratory and 3-D movie “Lake Tahoe in Depth” at the UC Davis Tahoe Science Center (also known as the Thomas J. Long Foundation Education Center) at 291 Country Club Drive in Incline Village, Nev. The center is open Tuesday through Friday from 1 p.m. to 5 p.m. year-round and on summer Saturdays from 1 p.m. to 5 p.m. Learn more at www.terc.ucdavis.edu.