Better wildfire management through knowledge of vegetation dryness

Increasing drought requires effective approach

The fire service’s Wildfire Spread Model has been expanded with a module that takes into account the dryness index of the local vegetation. The incorporation of this module improves the model’s predictions and also makes it possible to estimate the level of fire-risk at specific locations. This is particularly important now that lengthy droughts are becoming more frequent with climate change. The module was developed within TKI Technology by partners KWR, Vitens water utility, Vallei and Veluwe Water Authority, the independent administrative authority Institute for Safety (IFV), fire-research specialists Efectis, geo-ICT company Geodan and the Province of Gelderland.

Climate change is leading to more frequent (and lengthy) droughts, which increases the chance and the extension of wildfires. The fire service uses the Wildfire Spread Model to predict how, and how quickly, a wildfire will spread. The moisture content and evaporation behaviour of different plant species has been researched within the  TKI Water Technology programme, and the resulting knowledge has now been processed into a  supplementary module for the Wildfire Spread Model.


The new module improves the predictive power of the model, because the drier the vegetation the greater the impact it has on the spread of a wildfire. Calculations made for a specific location for example show that, under severe drought conditions, a wildfire spreads 1.3 to 1.6 times faster than normal – that is, at a speed of 500-600 meters per hour instead of 375 meters per hour. This demonstrates the importance for wildfire management of good information and accurate figures on the vegetation’s moisture content.

Predicting fire-risk

The new module can also be used to index how dry specific areas are, and thus the level of fire-risk they represent. This information is important, for instance, for the timely signalling of wildfires and the prevention of human casualties and damage to nature, buildings, drinking water supply and infrastructure.

Fire spreads faster during drought (right) than under ordinary conditions (left) (lines show the front of the fire, numbers in minutes)