Researchers developing wireless erosion sensors

TIJUANA, MEXICO — The National Oceanic and Atmospheric Administration (NOAA) is funding a research project to combine real-time sedimentation monitoring technology and educational outreach efforts in Los Laureles Canyon, located in the U.S./Mexico border community of Tijuana, Mexico, to address a pollution problem in the Tijuana River Watershed. According to the project website, “during coastal storm events, the effect of raw sewage, sediment, and trash generated upstream not only impacts Tijuana, but directly impacts the U.S. and Mexico beach water quality and coastal and ocean resources.”

Project objectives include installation and data monitoring from six wireless erosion sensor probes to be placed in situ in the sediments of Los Laureles Canyon to measure orientation (pitch, roll), temperature, pressure, strain, and conductivity, NOAA said. A goal of the pilot project is to determine whether these probes, buried at a depth of approximately 10 cm, will be able to quantify the amount of sediment, slope failure, and flooding that may be traveling from this upstream location to the Tijuana Estuary.

NOAA funded Kirk Martinez, Ph.D., from the University of Southampton’s School of Electronics and Computer Science, and Jane Hart, professor from the School of Geography, to develop fist-sized sensors to monitor erosion rates. By the end of this year, the researchers expect to have sensor probes that can predict the onset of landslides.

The fist-sized sensors have been placed in Los Laureles Canyon in Mexico, an area which is constantly under water because of torrential rain and mud slides.

“Nobody has ever tried putting radio-based sensors into slopes before,” said Martinez. “We are very close to having a miniaturized version that measures light, conductivity, and tilt.”

Six sensors have been placed upstream from the Tijuana estuary, which is just over the Mexican border in San Diego. The probes take a reading every hour, monitoring factors such as temperature and movement.

“Our challenge now is to get them measuring more and to have them really wake up when a storm is predicted,” said Martinez, who first developed sensor probes to monitor glacier movements in 2003. “We are already getting very good signs that we are getting a sense of the changes in sediment and soil through the sensors; the next move is trying to predict when things begin to change so that people living nearby can have early warnings of storms and landslides.”

According to the researchers, these sensors will be suitable to predict sudden landslides and flooding.

More information about the San Diego Coastal Storms project is available at https://sdcoastalstorms.org.