Understanding Grassland Curing for Fire and Land Management Operations in the Australian Capital Territory — ASN Events

Understanding Grassland Curing for Fire and Land Management Operations in the Australian Capital Territory (#109)

Malcolm J Gale 1 2 , Marta Yebra 2 3 , Danielle Martin 4 , Darius Culvenor 5 , Adam J Leavesley 1 2 , A Malcolm Gill 2 3 , Geoffrey J Cary 2 3 , Lauren De Waal 3 , Scott Farquhar 1 2
  1. ACT Parks and Conservation Service, Canberra, ACT, Australia
  2. Bushfire and Natural Hazards Cooperative Research Centre, Australia
  3. Fenner School of Environment and Society, Australian National University, Canberra, ACT, Australia
  4. Country Fire Authority, Victorian , Australia
  5. Environmental Sensing Systems, Melbourne Victoria

Understanding grassland fuel dynamics, in particular grass curing, is a key consideration for bushfire planning and operations. Accurate determination of the degree of grass curing is required for four public policy objectives: public warnings, fire response readiness level, fire behaviour predictions and fuel management activities such as slashing and grazing. The ACT Parks and Conservation Service is involved in hosting a collaborative methodological study comparing the outputs from different remote sensing methods, the CFA satellite-based grass curing model, a ground-based array of Normalised Difference Vegetation Index (NDVI) sensors, the “Green Seeker®” handheld NDVI sensor and human field observations. A system involving five sites strategically located to routinely collect visual curing levels using the CFA Grassland Curing Guide has been trialled since September 2014 in the ACT. At one of the sites an array of five NDVI sensors linked to a weather station has been installed and collecting NDVI data every 3 minutes and weather information every 2 minutes. At this site, in addition to the visual curing assessment, two samples of grass at each sensor are measured with the “Green Seeker®”, collected and transported to the laboratory to be weighed, dried (for 24 hours at 105°) and re-weighed to determine the Fuel Moisture Content (FMC). The objective of determining FMC is to test the suitability of these different remote sensing methods to capture FMC dynamics and to study the interactions between curing and FMC. Early results appear to show good agreement between the various methods.  This opens the possibility that land management agencies may be able to set up integrated systems to remotely monitor grass curing backed up by periodic visual observations. The advantages of such systems would be a reduction in the reliance on staff and volunteers for checking satellite data and reduced exposure to human subjectivity.

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