TY - JOUR
T1 - Field estimation of ash and char colour-lightness using a standard grey scale
AU - Roy, David P
AU - Boschetti, Luigi
AU - Maier, Stefan
AU - Smith, Alistair M S
PY - 2010/9/17
Y1 - 2010/9/17
N2 - Vegetation fires produce biomass combustion residues, with colour varying from dark black char to white mineral ash. The colour-lightness of char and ash combustion residues is a qualitative parameter describing the post-fire condition of burned areas, and has been correlated with the completeness of combustion, fire intensity, and fire duration. Researchers have suggested that visual comparison of combustion residue samples with a standard grey scale would enable reliable combustion residue colour-lightness estimation. This paper describes an experiment aimed at assessing if colour-lightness can be estimated using a standard grey scale. Fifteen combustion residue samples with colour-lightness ranging from black char to white mineral ash were collected in the Northern Territory, Australia, and visually evaluated by three individuals using a grey scale. The grey-scale scores (0-19) were compared with the mean visible (390 to 830 nm) wavelength combustion residue reflectance (0-1) measured with a portable spectroradiometer. A significant linear relationship between the grey-scale scores and the mean visible combustion residue reflectance was found (R2=0.816 with a linear fit, R2=0.936 with a logarithmic-transformed fit). This finding suggests that combustion residue colour-lightness can be assessed in the field using inexpensive grey scales, and that this technique is a suitable avenue for future research on the field assessment of fire characteristics and effects. � IAWF 2010.
AB - Vegetation fires produce biomass combustion residues, with colour varying from dark black char to white mineral ash. The colour-lightness of char and ash combustion residues is a qualitative parameter describing the post-fire condition of burned areas, and has been correlated with the completeness of combustion, fire intensity, and fire duration. Researchers have suggested that visual comparison of combustion residue samples with a standard grey scale would enable reliable combustion residue colour-lightness estimation. This paper describes an experiment aimed at assessing if colour-lightness can be estimated using a standard grey scale. Fifteen combustion residue samples with colour-lightness ranging from black char to white mineral ash were collected in the Northern Territory, Australia, and visually evaluated by three individuals using a grey scale. The grey-scale scores (0-19) were compared with the mean visible (390 to 830 nm) wavelength combustion residue reflectance (0-1) measured with a portable spectroradiometer. A significant linear relationship between the grey-scale scores and the mean visible combustion residue reflectance was found (R2=0.816 with a linear fit, R2=0.936 with a logarithmic-transformed fit). This finding suggests that combustion residue colour-lightness can be assessed in the field using inexpensive grey scales, and that this technique is a suitable avenue for future research on the field assessment of fire characteristics and effects. � IAWF 2010.
UR - http://www.scopus.com/inward/record.url?scp=77957005158&partnerID=8YFLogxK
U2 - 10.1071/WF09133
DO - 10.1071/WF09133
M3 - Article
VL - 19
SP - 698
EP - 704
JO - International Journal of Wildland Fire
JF - International Journal of Wildland Fire
SN - 1049-8001
IS - 6
ER -