Instruments and are used to monitor and detect changes in local conditions, including
Most of the measurements are taken at 1-minute intervals and data are transmitted hourly and displayed on graphs.
Rainfall on steep burned basins can transform into potentially dangerous flash floods and debris flows. In 2009, the Station Fire burned 160,000 acres in the San Gabriel Mountains. Vegetation has started to return, but it can take many years for a basin to fully recover from the effects of fire.
The USGS has installed instruments in a small basin of Arroyo Seco above Pasadena, CA. Data collection at this site supports research on the hydrologic factors that control debris-flow initiation in burned areas. The USGS conducted debris-flow monitoring at this site after the fire from 2009 to 2011. The USGS reestablished the monitoring site in the fall of 2015 to understand the effects of vegetation recovery on debris-flow susceptibility.