Wildfire occurrence patterns in ecoregions of New South Wales and Australian Capital Territory, Australia

Wildfire occurrence is regulated by many factors such as climate, vegetation, topography and ignition source. The effects of these factors vary across space. In this study, generalised additive models were used to assist in understanding the drivers that regulate the spatial distribution of wildfire occurrence over five ecoregions in the south-eastern Australia. Fire occurrence data are sourced from the moderate-resolution imaging spectroradiometer active fire product over the period 2003–2013 and across New South Wales and the Australian Capital Territory. The experimental results suggest that vegetation is one of the key factors in most ecoregions; among the two vegetation factors, vegetation formations affect the fire occurrence pattern in the most fire-prone area; climate gradients drive fire occurrence in ecoregions with relatively broad areas; spatial effect drives the fire occurrence pattern in all the ecoregions; anthropogenic factors regulate fire occurrence patterns in the most populated area and two sparsely populated areas. In the most fire-prone area, fires are less likely to ignite from rainforests and wet sclerophyll forests than in dry sclerophyll forests. Normalised difference vegetation index (NDVI) and fire occurrence follows a non-linear relationship with each other in most ecoregions, with small to medium levels of NDVI show positive effect. In the temperate areas, fires tend to ignite from low precipitation, high temperature areas. Fires are also likely to occur near human facilities and at non-protected areas in some ecoregions, but away from roads in one ecoregion. The findings from this study provide a better understanding of long-term fire patterns and their drivers that can potentially help fire managers and rural communities make strategic-level decisions.