Calculating fire danger of cured grasslands in temperate climates – the elements of the Grassland Fire Index (GLFI)

K.-P. Wittich; C. Böttcher; P. Stammer; M. Herbst

doi:10.1071/WF22062

RESEARCH ARTICLE (Open Access)

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Calculating fire danger of cured grasslands in temperate climates – the elements of the Grassland Fire Index (GLFI)

K.-P. Wittich ^A , C. Böttcher ^A ^* , P. Stammer ^A and M. Herbst ^A

+ Author Affiliations

- Author Affiliations

^A Deutscher Wetterdienst (German Meteorological Service), Centre for Agrometeorological Research, Bundesallee 33, D-38116 Braunschweig, Germany.

^* Correspondence to: christopher.boettcher@dwd.de

International Journal of Wildland Fire 32(8) 1212-1225 https://doi.org/10.1071/WF22062
Submitted: 4 May 2022 Accepted: 25 June 2023 Published: 19 July 2023

© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of IAWF. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Background

Increasing extreme weather events due to climate change require updated environmental monitoring and prediction systems in Germany.

Aim

The Grassland Fire Index (GLFI), developed by the German Meteorological Service ~15 years ago for temperate climates, was revised to improve fire-danger predictions during the fire season. Our paper gives insight into the new model version.

Methods

The former fire-behaviour core, i.e. Fosberg’s Fire Weather Index (FWI), is replaced by the standardised fire-reaction intensity, a different fuel-moisture of extinction term, and a replica of the fire-spread rate of the Canadian FFBP-System. A standardised ease-of-ignition index is added as a measure of ignition success. The fire module is supplied with diurnal dead-grass fuel-moisture calculations based on the water-budget and energy-balance concept.

Key results

The GLFI output is compared with diurnal fuel-moisture measurements and results of Wotton’s Grass-Fuel-Moisture model, Fosberg’s FWI, and Cheney’s rate of spread equation. The GLFI computes periods with a high fuel moisture more realistically, whereas it exceeds Cheney’s rate-of-fire spread systematically at lower wind speeds, which leads to higher danger ratings during calm-air conditions (as requested by users).

Conclusions and Implications

The GLFI estimates dead-fuel moisture and fire danger on open, horizontal topography according to the current scientific level. Model extensions are necessary to run the model on complex topography under varying greenness and occasional frost conditions.

Keywords: field and laboratory measurements, fire behaviour, fire intensity, fuel moisture, hourly fire-danger rating, ignition index, rate of spread, theoretical model.

References

Albini FA (1976) Estimating wildfire behaviour and effects. General Technical Report INT-30. (USDA Forest Service, Intermountain Forest and Range Experiment Station: Ogden, UT)

Alexander ME (1982) Calculating and interpreting forest fire intensities. Canadian Journal of Botany 60, 349-357.
| Crossref | Google Scholar |

Alexander ME, Heathcott MJ, Schwanke RL (2013) ‘Fire behaviour case study of two early winter grass fires in southern Alberta, 27 November 2011’. 76 p. (Partners in Protection Association: Edmonton, AB, Canada)

Alfieri JG, Niyogi D, Blanken PD, Chen F, LeMone MA, Mitchell KE, Ek MB, Kumar A (2008) Estimation of the minimum canopy resistance for croplands and grasslands using data from the 2002 International H₂O Project. Monthly Weather Review 136, 4452-4469.
| Crossref | Google Scholar |

Anderson HE (1982) Aids to determining fuel models for estimating fire behaviour. General Technical Report INT-122. (USDA Forest Service, Intermountain Forest and Range Experiment Station: Ogden, UT)

Anderson HE (1990a) Predicting equilibrium moisture content of some foliar forest litter in the Northern Rocky Mountains. Research Paper INT-429. (USDA Forest Service, Intermountain Research Station: Ogden, UT)

Anderson HE (1990b) Moisture diffusivity and response time in fine forest fuels. Canadian Journal of Forest Research 20, 315-325.
| Crossref | Google Scholar |

Aylor DE, Wang Y, Miller DR (1993) Intermittent wind close to the ground within a grass canopy. Boundary-Layer Meteorology 66, 427-448.
| Crossref | Google Scholar |

Beck JA, Alexander ME, Harvey SD, Beaver AK (2002) Forecasting diurnal variations in fire intensity to enhance wildland firefighter safety. International Journal of Wildland Fire 11, 173-182.
| Crossref | Google Scholar |

Beer T (1991) The interaction of wind and fire. Boundary-Layer Meteorology 54, 287-308.
| Crossref | Google Scholar |

Beer T (1993) The speed of a fire front and its dependence on wind speed. International Journal of Wildland Fire 3, 193-202.
| Crossref | Google Scholar |

Breinl K, DiBaldassarre G, Mazzoleni M, Lun D, Vico G (2020) Extreme dry and wet spells face changes in their duration and timing. Environmental Research Letters 15, 074040.
| Crossref | Google Scholar |

Byram GM (1959) Combustion of forest fuels. In ‘Forest fire: control and use’. (Ed. KP Davis) pp. 61–89. (McGraw-Hill: New York, NY, USA)

Campbell GS (1977) ‘An Introduction to Environmental Biophysics.’ (Springer Verlag: Heidelberg, Germany)

Catchpole EA, Catchpole WR, Viney NR, McCaw WL, Marsden-Smedley JB (2001) Estimating fuel response time and predicting fuel moisture content from field data. International Journal of Wildland Fire 10, 215-222.
| Crossref | Google Scholar |

Cheney NP (1981) Fire behaviour. In ‘Fire and the Australian biota’. (Eds AM Gill, RH Groves, IR Noble) pp. 151–175. (Australian Academy of Science: Canberra, ACT)

Cheney NP (1990) Quantifying bushfires. Mathematical and Computer Modelling 13, 9–15. 10.1016/0895-7177(90)90094-4

Cheney NP, Gould JS (1995) Fire growth in grassland fuels. International Journal of Wildland Fire 5, 237-247.
| Crossref | Google Scholar |

Cheney P, Sullivan A (1997) ‘Grassfires: fuel, weather and fire behaviour.’ (CSIRO Publishing: Melbourne, Australia)

Cheney NP, Gould JS, Catchpole WR (1993) The influence of fuel, weather and fire shape variables on fire-spread in grasslands. International Journal of Wildland Fire 3, 31-44.
| Crossref | Google Scholar |

Cheney NP, Gould JS, Catchpole WR (1998) Prediction of fire spread in grasslands. International Journal of Wildland Fire 8, 1-13.
| Crossref | Google Scholar |

Choudhury BJ, Reginato RJ, Idso SB (1986) An analysis of infrared temperature observations over wheat and calculation of latent heat flux. Agricultural and Forest Meteorology 37, 75-88.
| Crossref | Google Scholar |

Chuvieco E, Aguado I, Dimitrakopoulos AP (2004) Conversion of fuel moisture content values to ignition potential for integrated fire danger assessment. Canadian Journal of Forest Research 34, 2284-2293.
| Crossref | Google Scholar |

Couturier DE, Ripley EA (1973) Rainfall interception in mixed grass prairie. Canadian Journal of Plant Science 53, 659-663.
| Crossref | Google Scholar |

Cruz MG, Sullivan AL, Gould JS, Hurley RJ, Plucinski MP (2018) Got to burn to learn: the effect of fuel load on grassland fire behaviour and its management implications. International Journal of Wildland Fire 27, 727-741.
| Crossref | Google Scholar |

Cruz MG, Hurley RJ, Bessell R, Sullivan AL (2020) Fire behaviour in wheat crops – effect of fuel structure on rate of fire spread. International Journal of Wildland Fire 29, 258-271.
| Crossref | Google Scholar |

Cruz MG, Alexander ME, Kilinc M (2022) Wildfire rates of spread in grasslands under critical burning conditions. Fire 5, 55.
| Crossref | Google Scholar |

Davis WS (1949) The rate of spread - fuel density relationship. Fire Control Notes 10(2), 8-9.
| Google Scholar |

Dawson TE, Goldsmith GR (2018) The value of wet leaves. New Phytologist 219, 1156-1169.
| Crossref | Google Scholar |

de Groot WJ, Wardati , Wang Y (2005) Calibrating the Fine Fuel Moisture Code for grass ignition potential in Sumatra, Indonesia. International Journal of Wildland Fire 14, 161-168.
| Crossref | Google Scholar |

Deutscher Wetterdienst (2022) German Climate Atlas 2022. Available at https://www.dwd.de/EN/climate_environment/climateatlas/climateatlas_node.html [verified 1 June 2023]

Dimitrakopoulos AP, Mitsopoulos ID, Gatoulas K (2010) Assessing ignition probability and moisture of extinction in a Mediterranean grass fuel. International Journal of Wildland Fire 19, 29-34.
| Crossref | Google Scholar |

Forestry Canada Fire Danger Group (1992) Development and Structure of the Canadian Forest Fire Behaviour Prediction System. Forestry Canada, Information Report ST-X-3. (Science and Sustainable Development Directorate: Ottawa, Canada)

Fosberg MA (1978) Weather in wildland fire management: the Fire Weather Index. In ‘Proceedings of the Conference on Sierra Nevada Meteorology’, 19–21 June 1978, South Lake Tahoe, CA, USA. pp.1–4 (American Meteorological Society: Boston, MA)

Kidnie S, Wotton BM (2015) Characterisation of the fuel and fire environment in southern Ontario’s tallgrass prairie. International Journal of Wildland Fire 24, 1118-1128.
| Crossref | Google Scholar |

Legates DR, McCabe GJ (1999) Evaluating the use of “goodness-of-fit” measures in hydrologic and hydroclimatic model validation. Water Resources Research 35, 233-241.
| Crossref | Google Scholar |

Lex P, Wittich K-P (2002) Begünstigt das Mikroklima an Bahntrassen die Entstehung von Böschungs- und Waldbränden? AFZ-Der Wald 57, 6666-70 [in German].

Liang X, Su D, Yin S, Wang Z (2009) Leaf water absorption and desorption functions for three turfgrasses. Journal of Hydrology 376, 243-248.
| Crossref | Google Scholar |

Luke RH, McArthur AG (1978) ‘Bushfires in Australia’. Department of Primary Industry, Forestry and Timer Bureau. (CSIRO Division of Forest Research: Canberra, ACT)

Marsden-Smedley JB, Catchpole WR (2001) Fire modelling in Tasmanian buttongrass moorlands. III. Dead fuel moisture. International Journal of Wildland Fire 10, 241-253.
| Crossref | Google Scholar |

Matthews S (2006) A process-based model of fine fuel moisture. International Journal of Wildland Fire 15, 155-168.
| Crossref | Google Scholar |

Matthews S (2010) Effect of drying temperature on fuel moisture content measurements. International Journal of Wildland Fire 19, 800-802.
| Crossref | Google Scholar |

Matthews S (2022) Australian fire danger rating system: Fire behaviour index technical guide. Available at https://www.afac.com.au/initiative/afdrs/article/fire-behaviour-index-technical-guide [verified 1 June 2023]

McArthur AG (1966) Weather and Grassland Fire Behaviour. Commonwealth Department of National Development, Forestry and Timber Bureau Leaflet 100, Canberra, ACT.

McGechan MB, Pitt RE (1990) The rewetting of partially dried grass swaths by rain: Part 2, Exploratory experiments into absorption and drying rates. Journal of Agricultural Engineering Research 45, 69-76.
| Crossref | Google Scholar |

Menzel L (1997) Modellierung der Evapotranspiration im System Boden-Pflanze-Atmosphäre. Züricher Geographische Schriften 67, Geographisches Institut, ETH Zürich, Switzerland [in German].

Monteith JL (1965) Evaporation and environment. Symposia of the Society for Experimental Biology 19, 205-234.
| Google Scholar |

Müller C (1992) Waldbrandgefährdung und Waldbrandschutz im Land Brandenburg. Allgemeine Forstzeitschrift 18, 973-974.
| Google Scholar |

Müller R (2007) 61 Hektar in 5 Stunden – Analyse und Folgen des Großbrandes. ‘Fachtagung zur Bewirtschaftung und Ökologie der Kiefer im nordostdeutschen Tiefland’, 15–16 November 2007, Eberswalde, internal paper, 1 p. [In German].

National Wildfire Coordinating Group (2002) Gaining an understanding of the National Fire Danger Rating System. PMS 932, NFES 2665. (National Interagency Fire Center: Boise, ID, USA)

National Wildfire Coordinating Group (2008) Glossary of wildland fire terminology. PMS 205. (National Interagency Fire Center: Boise, ID, USA)

Nelson Jr RM (1983) A model for sorption of water vapor by cellulosic materials. Wood and Fiber Science 15, 8-22.
| Google Scholar |

NOAA-National Weather Service (2023) Glossary of fire weather terms. Available at https://www.weather.gov./phi/fire_glossary [verified 1 June 2023]

Noble JC (1991) Behaviour of a very fast grassland wildfire on the Riverine Plain of southeastern Australia. International Journal of Wildland Fire 1, 189-196.
| Crossref | Google Scholar |

Noble IR, Bary GAV, Gill AM (1980) McArthur’s fire-danger meters expressed as equations. Australian Journal of Ecology 5, 201-203.
| Crossref | Google Scholar |

Putuhena WM, Cordery I (1996) Estimation of interception capacity of the forest floor. Journal of Hydrology 180, 283-299.
| Crossref | Google Scholar |

Rothermel RC (1972) A mathematical model for predicting fire spread in wildland fuels. Research Paper INT-115 (USDA Forest Service, Intermountain Forest and Range Experiment Station: Ogden, UT)

Schroeder MJ (1969) Ignition probability. Office Report 2106-1. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station.

Sharples JJ (2009) An overview of mountain meteorological effects relevant to fire behaviour and bushfire risk. International Journal of Wildland Fire 18, 737-754.
| Crossref | Google Scholar |

Sneeuwjagt RJ, Frandsen WH (1977) Behavior of experimental grass fires vs. predictions based on Rothermel’s fire model. Canadian Journal of Forest Research 7, 357-367.
| Crossref | Google Scholar |

Sudmeyer RA, Nulsen RA, Scott WD (1994) Measured dewfall and potential condensation on grazed pasture in the Collie River basin, southwestern Australia. Journal of Hydrology 154, 255-269.
| Crossref | Google Scholar |

Sutherland RA (1986) Broadband and spectral emissivities (2–18 µm) of some natural soils and vegetation. Journal of Atmospheric and Oceanic Technology 3, 199-202.
| Crossref | Google Scholar |

Thompson N (1981) Modelling the field drying of hay. The Journal of Agricultural Science 97, 241-260.
| Crossref | Google Scholar |

Van Wagner CE (1972) Equilibrium moisture contents of some fine forest fuels in eastern Canada. Information Report PS-X-36. (Canadian Forestry Service, Petawawa Forest Experiment Station)

Vegas Galdos F, Álvarez C, García A, Revilla JA (2012) Estimated distributed rainfall interception using a simple conceptual model and Moderate Resolution Imaging Spectroradiometer (MODIS). Journal of Hydrology 468–469, 213-228.
| Crossref | Google Scholar |

von Deichmann V (1958) Untersuchungen über die Entzündlichkeit und Brennbarkeit von Bodendecken als Beitrag zu den Grundlagen einer Waldbrandprognose. Dissertation, Forstliche Fakultät, Georg-August-Universität Göttingen, Germany [In German].

Wilson Jr RA (1985) Observations of extinction and marginal burning states in free burning porous fuel beds. Combustion Science and Technology 44, 179-193.
| Crossref | Google Scholar |

Wilson Jr RA (1990) Reexamination of Rothermel’s fire spread equations in no-wind and no-slope conditions. Research Paper INT-434. (USDA Forest Service, Intermountain Research Station: Ogden, UT)

Wittich K-P (2005) A single-layer litter-moisture model for estimating forest-fire danger. Meteorologische Zeitschrift 14, 157-164.
| Crossref | Google Scholar |

WMO (2008) ‘Guide to Meteorological Instruments and Methods of Observation. WMO-No. 8, Vol. 1, Measurement of Meteorological Variables.’ (World Meteorological Organization: Geneva) Available at https://www.weather.gov/media/epz/mesonet/CWOP-WMO8.pdf [verified 1 June 2023]

Wotton BM (2009) A grass moisture model for the Canadian Forest Fire Danger Rating System. In ‘Proceedings 8th Symposium on Fire and Forest Meteorology’, Kalispell MT, 13–15 October 2009. Paper 3A.2. (American Meteorological Society)

Wright JG, Beall HW (1945/1968) The application of meteorology to forest fire protection. Technical Communication No. 4. Imperial Forestry Bureau, Oxford. Information Report FF-X-11. (Reprinted by Forest Fire Research Institute, Department of Forestry and Rural Development: Ottawa, Canada)

Zhou X, Mahalingam S, Weise D (2005) Modeling of marginal burning state of fire spread in live chaparral shrub fuel bed. Combustion and Flame 143, 183-198.
| Crossref | Google Scholar |

Zolina O, Simmer C, Belyaev K, Gulev SK, Koltermann P (2013) Changes in the duration of European wet and dry spells during the last 60 years. Journal of Climate 26, 2022-2047.
| Crossref | Google Scholar |