Just Accepted
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Using hydrological modeling to improve the Fire Weather Index system over tropical peatlands of Peninsular Malaysia, Sumatra, and Borneo
Jonas Mortelmans 
, Sebastian Apers , Gabrielle De Lannoy, Sander Vereverbeke, Robert Field, Niels Andela, Susan Page, Michel Bechtold
Abstract
Background. Tropical peatland fires contribute to global carbon emissions and air pollution. Aims. Enhance the globally used Canadian Fire Weather Index (FWI) system specifically over drained and undrained tropical peatlands in Southeast Asia. Methodology. We included simulated tropical peatland hydrology in the FWI, creating a new peatland-specific version of the FWI (FWIpeat). FWIpeat, the original FWI (FWIref), and the drought code (DC) were evaluated against satellite-based active fire occurrence from 2002-2018. Key Results. The DC shows superior performance in explaining fire occurrence over undrained tropical peatlands. Over drained peatlands, DC and FWIpeat show similar results, both outperforming FWIref. A comparison with an earlier study over boreal peatlands indicates much smaller improvements by the FWIpeat for tropical peatlands possibly due to a lower accuracy of the hydrological input data. Conclusions. Our results highlight the importance of including information on the deeper soil layers, being the DC or groundwater table, when assessing fire danger. Implications. While this study offers a promising approach for operational fire management over tropical peatlands, we emphasize the need for further research to refine the hydrological input data and explore additional constraints from Earth observation data.
WF24057 Accepted 20 January 2025
© CSIRO 2025
