Using InSAR to assess the impact of tropical cyclones on asbestos tailings containment in the Pilbara

Project Information

Wittenoom is in the semi-arid Pilbara region in Western Australia and is recognised as the largest contaminated site in the southern hemisphere. Owing to its hazardous nature, it is a good candidate for remote monitoring methods. The Wittenoom Asbestos Management area (WAMA) covers an area of 468.4 km2 (or 46,840 hectares). The WAMA incorporates the former Wittenoom townsite, as well as Wittenoom gorge, Yampire Gorge and the Joffre floodplain. Asbestos contamination derived from historical mining activities at the former Wittenoom Mine, Colonial Mine and Yampire Mine, which mined crocidolite (blue asbestos) until closure of the mines and mills in 1966. Stockpiles of tailings have been eroded and dispersed since mining operations have ceased and now extend away from the mine sites.  The lack of access and the constraints owing to the contaminated lands make it challenging for land managers to effectively monitor piled tailings and therefore contaminant dispersal at Wittenoom.

Interferometric synthetic aperture radar (InSAR) is a geodetic technique employs variations in the phase of the waves returning to the satellite or aircraft from two or more synthetic aperture radar (SAR) images to create maps of surface deformation or digital elevation.  The method may be able to detect deformation changes at the millimetre scale over periods ranging from days to years. It can be used in structural engineering, namely for monitoring of subsidence and structural stability, as well as geophysical monitoring of natural hazards including earthquakes, volcanoes, and landslides.

The project will assess the suitability of using InSAR methods for remote mine tailings monitoring.

• This project will map the current extent of exposed Wittenoom tailings using remotely sensed methods
• Understand the stability and/or dispersion of the tailings from forces occurring from named tropical cyclone events

The project will make use of the UNSW in-house software GEO-ADPS and GEOS-AUTOPSI in addition to other programs to create a time-series of interferograms for the Hamersley Ranges area to explore SAR sensor capabilities for mapping tailings dispersal in Western Australia.   Synthetic Aperture Radar (SAR) sensors such as X-band, CSK and Terra-SAR-X (~3m resolution) in addition to Sentinel-1, L-band, ALOS-2 (~10m resolution) will be explored to quantify tailings dispersal resulting from landscape processes and weather events at a local and meso-scale.

The Pilbara is characterised by extreme hydroclimatic conditions, in which the rainfall is highly sporadic but driven by infrequent tropical cyclones and thunderstorms occurring in the summer months or winter rainfall typically from low pressure trough systems. Named cyclone events will be used as initial starting point to explore the role of rainfall and surface run-off in contaminant dispersal.

Requirements

We are seeking a highly motivated, reliable and creative individual with ability to carry out scientific research, work as a team and disseminate the results. Training in GEO-ADPS and GEOS-AUTOPSI packages as well as support developing InSAR methodology will be provided, however it is expected that the candidate will have:

• A strong background in remote sensing, computing or earth science
• Skills in programming in C++ or Scripting languages such as Python or Matlab (and willingness to maintain these throughout the project duration
• Motivation to cooperate in a diverse and multidisciplinary research team

This is a collaborative project between UNSW Canberra, UNSW Sydney and Geoscience Australia. It is expected that the candidate will be based at UNSW Canberra short visits to UNSW Sydney. Some fieldwork to the Pilbara can be arranged to understand the landscape and environment depending on the candidates preferred research direction.

Supervisors