Geophysical flow dynamics using pulsed Doppler radar

Lead Research Organisation: University of Sheffield
Department Name: Civil and Structural Engineering


Mass movement flows are a significant natural hazard throughout the world and yet our ability to predict their behaviour and plan for their effects is limited, in part, by our lack of understanding of their flow dynamics. This research will investigate the dynamics of geophysical mass movement flow processes (specifically snow avalanches and pyroclastic flows) by means of carefully-controlled trials at avalanche and volcano test sites. This research will utilise a sophisticated and new Doppler radar imaging instrument, able to form two-dimensional animated images of a variety of geophysical events. This radar has been under development at University College London, supported by the Royal Society, and permits imaging of the dense parts of the flow (often the most important component for risk analyses) by penetrating the suspended matter surrounding snow avalanches and pyroclastic flows. Advanced signal processing algorithms will be used to generate detailed models of the structure and dynamics of the flow. At present, opto-electronic instruments can provide such information at a single point and existing Doppler radar can provide crude images of the flow speed, but averaged over 50 m and only giving an overall measure of the velocity magnitude (with no information on direction). Our instrument will reduce the averaging distance to just 1 m so that, for the first time, information on individual blocks in the flow can be obtained and assessed in relation to their significance for the overall flow dynamics. Thus, we can assess the validity of a variety of flow laws that have been proposed for describing such processes. This will lead to improved models for these flow processes by limiting the values of coefficient in the models to reasonable values and rejecting some proposed flow laws outright. This will lead to more accurate modelling of these processes, which in turn will improve risk analyses and the design of defensive structures. This study will therefore considerably increase our understanding of flow movement and raise the status of UK research in this area to internationally-leading standards.

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/F00415X/1 31/05/2008 30/09/2010 £21,534
NE/F00415X/2 Transfer NE/F00415X/1 30/09/2010 31/12/2011 £6,131
Description We have built the new radar system and installed it at the avalanche test site in Switzerland.

Data from the avalanches examined so far has been validated using other in-path instrumentation.

Our instrument reveals unprecedented detail in terms of the structure of the flow, with surge wave instabilities readily identifiable in the moving target images produced.
Exploitation Route Information will assist numerical model development which will then feed into applied engineering - e.g. risk assessments for alpine constructions.
Sectors Electronics,Environment

Description Since this radar was constructed, there has been significant international interest in our work. We have used this project as a point of departure for developing a new instrument with a better azimuthal (lateral) resolution as part of EPSRC project EP/K007688/1.
First Year Of Impact 2011
Sector Electronics,Environment
Description Advanced MIMO Radar Development for Geophysical Imaging Applications
Amount £36,000 (GBP)
Funding ID EP/K007688/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2013 
End 01/2016
Title Gradual Wavelet Reconstruction 
Description This method permits controlled randomisation of time series for studying their nonlinear characteristics, or for modelling data by including given nonlinear characteristics. It is wavelet-based and extends previous Fourier-based methods. 
Type Of Material Data analysis technique 
Year Produced 2010 
Provided To Others? Yes  
Impact There have now been applications of this method in hydrology and fluid mechanics, with more being developed in neuroscience. It is supporting the analysis of the data in the funded research projects (e.g. analysing avalanche radar data). 
Description PhD collaboration on avalanche dynamics and signal processing 
Organisation National Research Institute of Science and Technology for Environment and Agriculture
Country France 
Sector Public 
PI Contribution Supervising the second half of the PhD and providing expertise on wavelet data processing.
Collaborator Contribution Provided funds to support the first half of the PhD via a EU research project.
Impact We have a paper in review and the PhD thesis is about to be submitted.
Start Year 2014
Description SLF collaboration 
Organisation Swiss Federal Institute for Forest, Snow and Landscape Research
Department WSL Institute for Snow and Avalanche Research SLF
Country Switzerland 
Sector Academic/University 
PI Contribution We have developed and tested the radar for measuring snow avalanche dynamics. We have travelled to the site to make measurements.
Collaborator Contribution Swiss colleagues have helped install the instruments on their site (which is difficult to access) and helped install appropriate power and data recording facilities
Impact We have published papers together (reported elsewhere) and developed a stand for the Royal Society Summer Science Exhibition.
Start Year 2008
Description Popular Science Writing 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Myself and colleagues and the project wrote some popular science articles in Geography Review (school pupils) and Geology Today (undergrad. up to research level) on the findings from our project.
Year(s) Of Engagement Activity 2015
Description RoyalSociety Summer Science Exhibition 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Active discussion with many members of the public and a large number of website hits. Discussion with policy makers (both Houses) at the evening soiree.

A video from our work featured on ITN News at Ten when avalanche fatalities occurred in the following week.
Year(s) Of Engagement Activity 2012
Description School Visits (Bedford) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact 120 pupils attended from 3 local schools to hear me talk about avalanche research to complement material in the Geography syllabus.
Year(s) Of Engagement Activity 2016
Description School talk (Leeds) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact I gave a talk to a group of sixth form students about our research.
Year(s) Of Engagement Activity 2015