Novel Instrumentation

Background

The Eel River Critical Zone Observatory is a research group that studies the thin slice of Earth starting where unfractured bedrock begins, up to just above the tops of trees. This is called the critical zone. It is also where we live.

Along California’s coastline, water is stored in neither soil nor snowpack. Instead, the majority of the water is stored in weathered bedrock. This storage site is called the Vadose Zone. It is often labelled the “Unmeasured Zone” because it is so difficult to monitor water in fractured rock.

Methods and Instrumentation

ERCZO chose to intensively monitor a single site within the Angelo Reserve, Mendocino, California. They placed 1,000 sensors into fractured rock, soil, sap flow in trees, and weather stations on the surface. With this array of sensors, the ERCZO traced raindrops and their effect upon both the living and nonliving parts of the environment.

Their deployment included the Vadose Monitoring System (VMS), a unique-in-the-world instrument, constituting two 45 degree angle bore-holes drilled into a hillside, a plastic sleeve with sensors stitched into the outer surface fitted into each bore-hole, then concrete poured through the center to expand the sleeve like a balloon, pressing the sensors against the fractured rock of the bore-holes.

All of this equipment, from standard Campbell Scientific weather stations, to the highly experimental VMS are connected in real time through wireless to Dendra. Dendra manages the entire site, stores and delivers the data to the researchers, and sends warnings when communication goes down for any of the dataloggers.

Results and Future Outlook

With roughly 40 million Californians depending on water from rivers during the summer, it is becoming more and more critical to understand and model this water supply. Dendra provides a flexible infrastructure that allows innovative systems such as the VMS to be used to advance our understanding of the natural world.

Learn More

The ERCZO at Angelo Reserve: https://angelo.ucnature.org/erczo/

Funding: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1331940

See ERCZO Publications: https://angelo.ucnature.org/erczo/eel-river-critical-zone-observatory-publication-list/