HyMap maps Victorian bush fires
A New View of a Bushfire’s Aftermath
We have all seen the photographs of burnt houses, cars and forests but a hi-tech airborne imaging system allows us to take a step back and see the aftermath with new eyes. From this we can gain new insights and knowledge about the fire intensity patterns, it’s impact on the environment and assess potential future hazards such as increased wind and water driven soil erosion and contamination of our water supply with ash.
Hi-resolution digital image of Kinglake acquired by HyVista Corporation - 27th February 2009
If the fires of February 2009 are the pointy end of climate change for south-eastern Australia, then advanced remote sensing instruments such as the HyMap hyperspectral sensor that was flown over the Killmore-Murrindindi fires scars last week could provide an invaluable baseline view of the environmental impact of such firestorms over large areas. Long term use of this technology permits us the opportunity to watch and learn more about how the environment recovers or perhaps as climate change modeling suggests, changes forever.
Last week, a remote sensing company, HyVista Corporation, acquired several images over the Victorian burn scars to demonstrate the application of this advanced remote sensing technology. The airborne imaging system used was developed in Australia and for more than a decade has been at the forefront of illustrating and applying the technology to a wide range of mapping tasks such as mineral exploration, agriculture, energy resources (oil, gas and geothermal), coastal mapping (bathymetry) and environmental monitoring. The United States government has also used this Australian sensor in its assessment of wildfire impact in California, Alaska, Idaho and Wyoming.
Recently, the sensor was used by the United States Geological Survey to image almost all of Afghanistan (an area more than twice the size of Victoria) in a project aimed to produce a country-wide, new geological map that will aid exploration for mineral and oil deposits and thus contribute to the economic development of Afghanistan.
Able to image in excess of 1000 sq kilometers (100,000 hectares) per day, HyVista Corporation had planned to survey most of the Killmore-Murrindindi burnt areas in its two day demonstration deployment but smoke and cloud frustrated that goal. However, some imagery was acquired over and around Kinglake and image analysts at HyVista Corporation have generated a few mapping products shown below.
HyMap image products of Kinglake, Victoria - 27th February 2009
The panels in the image to the left show part of the HyMap image strip over Kinglake.
The top panel is a true colour representation with the town of Kinglake near the centre of the panel.
The middle panel was derived from HyMap wavelengths to simulate the colourisation that could be obtained using imagery from the Landsat image, albeit not at such high spatial resolution.
The bottom panel illustrates the real power and advantages of hyperspectral imaging.Using the spectral signatures of the surface materials, one can identify and the accurately (and rapidly) map the surface materials. In this example, 5 materials are identified, mapped, assigned various colours and then combined to present what is essentially an information map. Many other materials or their “state” could also be identified and mapped including exposed soils and the soil make-up (e.g. clay content), vegetation species, leaf water content (an indicator of vegetation dryness).
It is possible to detect and map all non-natural features in the landscape such as buildings, roads, oil or chemical spills, even single vehicles (perhaps of interest to search and rescue operations), and all rapidly over thousands of square kilometers (hundreds of thousands of hectares).