This study distinguishes between meteorological droughts (lower than average rainfall) and hydrological droughts, where rainfall shortage has eventually led to surface or groundwater levels falling, to predict area burnt from wildfires. By contrast, most studies consider only climate data when predicting wildfire, yet “these overlook subsurface processes leading to hydrological drought, an important driver” [Taufik 2017: 428].
The authors hypothesize that periods with low groundwater recharge will create conditions for a greater area burnt. They found that massive wildfires in Borneo over the past two decades coincided with years when there were large areas of hydrological drought.
Statistical modelling evidence shows amplifying wildfires and greater area burnt in response to El Niño/Southern Oscillation (ENSO) strength, when hydrology is considered. [Taufik 2017: 428]
Hydrological drought stems from a lack of rain, but also depends on the ability of the land to store water. Thus, land use can exacerbate a hydrological drought.
Human activities through land-use change and associated drainage and land clearing immediately following deforestation or long fallow periods create favourable conditions for the fires and amplify the hydrological drying processes in the aboveground fuels and the underlying organic soil [Taufik 2017: 428].
Human activities through land-use change and associated drainage and land clearing immediately following deforestation or long fallow periods create favourable conditions for the fires and amplify the hydrological drying processes in the aboveground fuels and the underlying organic soil [Taufik 2017: 428]. |
Taufik, Muh, Paul J. J. F. Torfs, Remko Uijlenhoet, et al., 2017, Amplification of wildfire area burnt by hydrological drought in the humid tropics, Nature Climate Change 7, https://www.nature.com/articles/nclimate3280.