Images

A scientist installs a hillslope monitoring station in the 'Heil Ranch' section of the 2020 Calwood Fire burn area.  Hillslope monitoring stations collect data about rainfall and soil properties, and record debris flows that occur in burned watersheds.  

Approximately 7 months following the Calwood Fire, Boulder County, Colorado vegetation begins to regrow on the burned hillslope.  

Overview photograph of the area burned by the 2020 Calwood Fire in Boulder County, Colorado.  The hillslopes are covered by burned tree remnants and boulders. In this view, very little vegetation has returned.  

Burned hillslope in the 2020 Calwood Fire burn area, Boulder County, Colorado.  This hillslope sits above a very small drainage area and is still devoid of vegetation approximately 7 months following the fire.  Small rills or incisions on the slope formed in areas where runoff became concentrated.  

Rain Gauge installed after the 2020 Grizzly Creek fire in Glenwood Canyon, Colorado. Scientists installed a network of rain gauges and soil moisture sensors throughout the rugged burn area. These instruments provide real-time data on rainfall intensity and duration, which are critical factors in determining the likelihood of a debris flow. 

Rain gauge installed in Glenwood Canyon, Colorado. After the 2020 Grizzly Creek fire, scientists installed a network of rain gauges and soil moisture sensors throughout the rugged burn area. These instruments provide real-time data on rainfall intensity and duration, which are critical factors in determining the likelihood of a debris flow. 

Rain gauge in Glenwood Canyon, Colorado. After the 2020 Grizzly Creek fire, scientists installed a network of rain gauges and soil moisture sensors throughout the rugged burn area. These instruments provide real-time data on rainfall intensity and duration, which are critical factors in determining the likelihood of a debris flow. 

Three soil moisture sensors shown before their installation in a soil pit. The sensors will form a vertical subsurface array geared to track infiltration behavior. 

This photograph of a small watershed within the 2020 Calwood Fire burn area, Boulder County, Colorado was taken 6 months following the fire.  The removal of vegetation and change in soil properties make steeply burned areas susceptible to postfire debris flows.  

Scientists installed a hillslope monitoring station following the 2020 Calwood Fire, Boulder County, Colorado.  These monitoring stations help to collect data, such rainfall and soil moisture, that is used to better understand postfire debris-flow processes.

Soil pit shown with three soil moisture sensors installed in a subsurface vertical array. The wetting and drying of the soil will be tracked over multi-annual timescales. 

A soil moisture sensor shown prior to installation in a soil pit. This kind of sensor measures the dielectric constant of the soil using capacitance and frequency domain technology.

Scientists install the 'Heil Ranch' monitoring station on a steeply burned hillslope within the 2020 Calwood Fire burn area, Boulder County, Colorado.  The monitoring station collects data following wildfire to support research on postfire debris-flow processes.

Hillslopes in the 2020 Calwood Fire burn area covered by burned and partially burned trees. This photo was taken approximately 6 months after the fire.  

Postfire monitoring station within the 2020 CZU Lightning Complex burn area.  This photograph was taken in February 2021 approximately 4.5 months after the fire was contained.  

Postfire monitoring station within the 2020 CZU Lightning Complex burn area.  This photograph was taken in February 2021 approximately 4.5 months after the fire was contained.  

Rilling and a shallow landslide in CZU Fire near Eagle Rock, California. Soil ~3 cm below surface was almost completely dry after the rain storm, highlighting soil water repellancy.  

The effects of debris floods following the 2020 River Fire in Monterey County, California. 

Photo credit: Matthew A. Thomas, U.S. Geological Survey

The storm that hit California’s coast between Jan. 26 and 28, 2021, blew out a portion of Hwy 1 near Big Sur. On Saturday, a USGS reconnaissance flight snapped this dramatic photo above the Rat Creek drainage showing the debris flow.

On Sunday, August 16, 2020 at approximately 3:00 PM PST, the River wildfire ignited in Monterey County, California, just west of the Salinas River Valley.

 Debris flow deposit at the outlet of the Tumalt Creek drainage basin, Columbia River Gorge, Oregon,  following storms in January 2021.