18-9. New techniques for debris flow monitoring and model validation

Through this research opportunity we seek a candidate to leverage off-the-shelf technologies to make advancements in our ability to detect and characterize fast-moving debris flows and lahars. The goal is to better inform debris-flow modeling and expand our monitoring capabilities. Debris flows and lahars are fast-moving, channelized flows that can travel large distances and threaten human populations worldwide. They have a high hazard potential due to their sudden onsets and long reaches.  For example, the deadly post-wildfire debris flows in January 2018 in Montecito, California killed 23 people and damaged and destroyed hundreds of homes or the relatively recent 1985 Armero tragedy in Colombia, where 23,000 people were killed by lahars. Our own volcanoes pose similar hazards for which we need to prepare. For example, thousands of people now live atop relatively recent lahar deposits near Mount Rainier where lahars can occur even in the absence of volcanic unrest, mobilized by large landslides.

Scientific advancements over the past decades, many made by the USGS, allow us to readily identify general areas and time periods when debris flow hazards are elevated. We can identify rainfall thresholds and specific recently burned drainages or areas of recent volcanic activity where debris-flow mobilization is likely. However, understanding the fundamental risks posed by debris flows in burned or volcanic settings, requires making high precision measurements of the events. In addition, many lahars are unheralded and thus early warning systems are sometimes implemented to warn downstream populations if an event is underway. With currently available systems, multiple sensors must be installed along every single drainage to be monitored and data must be telemetered with low time-lags to be able to evacuate susceptible areas, and the information these systems can provide is limited. The cost and logistics of this requirement reduces the number of drainages that are monitored and increases maintenance costs. A modernization of detection methods using new technologies and innovative multiparametric algorithms could increase warning times by detecting events closer to the source, and could provide probabilistic alarms based on multiple streams of information. Furthermore, with detailed measurements of flow velocity, depth, surge spacing, and duration, we can better assess and model the fundamental processes that threaten life and infrastructure.  Making progress on these fronts requires data from real events, but it is challenging and expensive to make such measurements, so data are limited. A suite of low-cost instruments deployable in the field could help to build a larger database of these measurements. 

We seek a candidate to work on developing algorithms and techniques to detect flows and measure debris-flow velocity, discharge, flow depth and particle concentration using a suite of in situ sensors. This may involve developing new frameworks for existing techniques or developing new techniques and algorithms involving off-the-shelf and existing technologies, such as lasers, cameras, video cameras, force plates, seismometers, and infrasound sensors. Techniques and algorithms can be tested in a semi-controlled setting at the USGS flume, using numerical modeling, and using natural sites with frequent debris flows such as Chalk Cliffs, CO, drainages at volcanoes in the Pacific Northwest, and/or recently burned sites prone to debris flows. Machine learning and High Performance Computing can be used with the collected datasets to train and validate algorithms to, for example, detect changes in flow characteristics like particle concentration or mean velocity. With increasingly sophisticated monitoring networks around volcanoes, it is also important to devise a quantitative, defensible method to provide multiparametric alarms of lahar occurrence with uncertainty.  It will also be important to consider how the alarm and its uncertainty will vary in time. Done well, the uncertainty in alarms could dictate the distribution of that alarm to emergency managers, community leaders, and the general public.   

Interested applicants are strongly encouraged to contact the Research Advisor early in the application process to discuss project ideas.

Proposed Duty Station: Golden, CO

Areas of PhD: Geophysics, geology, hydrology, engineering or related fields (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).

Qualifications: Applicants must meet the qualifications for:  Research Geophysicist, Research Engineer, Research Geologist, Research Hydrologist. 

(This type of research is performed by those who have backgrounds for the occupations stated above.  However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)

Human Resources Office Contact: Audrey Tsujita, 916-278-9395, atsujita@usgs.gov