Surveying Natural Disaster Areas
Measuring and assessing the impacts of disasters such as infrastructure and building damage is an essential part of the recovery process following a natural disaster to help those affected rebuild their lives. Assessments typically take months using traditional methods.
The Rapid Inventory Collection System (RICS) is a mobile machine vision based system developed at Geoscience Australia that captures geo-tagged digital images of structures and buildings for quick field damage assessments in disaster affected areas. The system complements existing field-work by allowing a full coverage of building damage extent through the capture of thousands of image data in a short period of time. This helps engineering and geoscience staff to establish and prioritise the worst hit areas for more efficiency.
RICS consists of two to four Prosilica GC2450 cameras fitted with Fujinon 12.5mm or 16mm focal length lenses in Swann 1020 weather proof housings mounted on top of a vehicle, a five-port Ethernet switch, a GPS receiver and a high-end laptop. The system uses an inverter to supply power from the vehicle’s auxiliary plug to the laptop and network switch while the cameras are powered by batteries.
RICS’ user interface consists of three sections; images, GPS data and notepad. Streamed images are displayed in the top section while the GPS data displayed in the middle section includes the time, latitude, longitude, bearing, number of satellites, fix quality and speed. The bottom section notepad allows users to type notes during a field session.
The RICS software is an open-source software that was implemented in C++ using Microsoft Visual C++ Express. Image capture, streaming (via the Ethernet network) and compression is performed on a separate thread for each camera. The GPS data is also performed on a separate thread. Image data and their corresponding GPS data are stored using SQLite for post-analysis.
First mission: The 2009 Victorian Bushfires
RICS was first deployed in 2009 to assess residential and commercial structure damage following the February Victorian bushfires. Unprecedented in Australian history, the February 2009 Victorian bushfires quickly spread across 78 townships devastating over 400,000 hectares of land and causing over 200 fatalities.
Damage assessment of fire impact was undertaken using a combination of Google Street View where available, before and after aerial imagery and RICS. RICS and Google Street View played an important role in delineating differences between houses and other buildings such as sheds and animal shelters as well as eliminating structures that were ruins prior to the fire from the database. RICS provided total coverage of the residential structures within 200 metres of roads and tracks. Three cameras were used to collect over 500,000 images of approximately 8,000 structures over a period of three weeks.
A large number of fires were reported in five regions with approximately 5,400 residential structures within the fire perimeter. The RICS impact assessment of the Victorian fires indicated that over 2,100 homes were destroyed while an additional 800 received minor damage. RICS was also useful for assessing the state of the burnt vegetation near population centres and aided the validation of the remotely-sensed imagery depicting the fire intensity.
Since then, RICS was deployed in the 2010 Kalgoorlie and Christchurch Earthquakes, 2011 Brisbane floods and Tropical Cyclone Yasi to collect geo-tagged imagery of damaged structures and buildings, and was also recently used to capture geo-tagged imagery of the Darling River in New South Wales for ecological research.
Pictures: © Copyright Geoscience Australia