Scientific perspectives on wildfire risk management at the WUI property scale

Portugal research centre leads international release on WUI wildfire risk management

The Forest Fire Research Centre of ADAI, based at the University of Coimbra in Portugal, has coordinated the publication of a new open-access scientific volume on wildfire risk management at the property scale in the wildland-urban interface (WUI).

According to CTIF, the book titled Scientific Perspectives on Wildfire Risk Management at the WUI Property Scale presents contributions from 34 researchers across 10 countries, addressing how built environments can be made more resistant to wildfire damage.

The book is freely available online via the University of Coimbra’s digital press.

Book introduces scientific context for wildfire risk in WUI areas

CTIF reported that the publication aims to provide a knowledge base for more effective wildfire risk reduction strategies at the interface between natural and built environments.

The introduction to the book, written by Jack Cohen, retired US Forest Service research scientist and WUI fire expert, outlines decades of fire loss in the United States and highlights the need for ignition-resistant design.

Cohen wrote: “A trend of increasing community destruction during wildfires is apparent. The United States provides a prime example.

“In 1985, 1400 homes and structures burned during wildfires. This motivated the establishment of the US national Wildland-Urban Interface Initiative.

“Approximately 9000 homes burned during US wildfires from 1985 to 1994. The recent decade from 2012 to 2021 had over 45,000 US homes burn during wildfires.”

Local ignition conditions determine wildfire damage to homes

Cohen stated that the primary cause of property destruction in WUI fires is not direct flame contact from wildfire fronts but ignitions due to embers and heat exposure in the immediate vicinity of homes.

He explained: “Research results indicate practical opportunities for effectively creating ignition resistant homes and thereby preventing community fire disasters without necessarily controlling wildfires.”

He added: “Disaster examinations have determined that intense wildfire flame fronts do not continuously spread within communities having moderate to high structure density.

“A community’s streets, utility corridors, driveways, parking areas and building sites create gaps in the continuous tree and shrub canopies that cease high intensity wildfire spread.”

Preface outlines need for design and mitigation strategies at the property scale

The preface of the book discusses the concept of the Home Ignition Zone (HIZ), defined as the area within 30 metres of a structure, and notes that ignition resistance within this zone is key to reducing community-level wildfire risk.

Cohen wrote: “The typical WU fire patterns indicate a structure’s local conditions principally determine its ignition.

“Unburned area surrounding the destroyed home indicates lofted burning embers as the principal source of ignition directly on the home or from ignited materials immediately adjacent.”

He continued: “Reducing structure ignition potential remains the principal factor for reducing community wildfire risk.

“Thus, WU fire disasters must be defined and approached as a home-structure ignition problem, not as a problem of wildfire control.”

Conclusions call for broader collaboration including citizen involvement

Miguel Almeida, Senior Researcher at ADAI and coordinator of the publication, concluded that more stakeholders need to be involved in WUI wildfire risk management.

Almeida stated: “The increasing frequency and severity of wildfires in the wildland-urban interface across the globe underscore the critical importance of understanding and managing wildfire risk at these areas.

“Recent dramatic fires have highlight the need for continued research and practical application in both operational and policy-making spheres.”

He added: “One of the key challenges highlighted by recent wildfire events is the incapacity and insufficiency of public civil protection services to address all incidents during very large-scale fires.
There is a growing recognition that citizens must play an active role in this challenge.”

The book presents international research on property-scale wildfire mitigation

CTIF reported that each chapter was coordinated by its lead author and presents independent analysis on topics ranging from WUI characterisation and ignition mechanisms to regulations and fire behaviour modelling.

The book includes sections on self-protection systems, defensible space design, and insurance policy development as it relates to wildfire risk.

According to Almeida, the structure of the book allows readers to explore the topic progressively or by interest area.

Almeida stated: “While some redundancy or varying approaches to the same topic may be detected through the book due to the independent nature of the chapters, they follow a logical sequence that allows readers to progress over the book methodically.

“These chapters collectively demonstrate that there are multiple, complementary approaches to managing wildfire risk in the WUI.”

Researchers from ten countries contribute to the open-access volume

CTIF listed the contributors as including scientists and engineers from Portugal, the United States, Chile, Israel, Spain, France, Japan, China, South Korea, Australia and New Zealand.

The authors represent academic institutions, national research organisations, and operational fire services.

The book is available for free download via the University of Coimbra’s academic press.

Contributing authors

Miguel Almeida, Luís Mário Ribeiro, Domingos Xavier Viegas, MohammadReza Modarres, Hafsae Lamsaf and Almerindo Ferreira from ADAI, University of Coimbra, Portugal; Dulce Lopes and Inês de Oliveira Martins from the University of Coimbra – Institute for Legal Research and Faculty of Law, Portugal; Jack Cohen from the US Forest Service (retired), USA; Albert Simeoni from Worcester Polytechnic Institute, USA; Pedro Reszka from Universidad Adolfo Ibáñez, Chile; Avi Bar-Massada from the University of Haifa, Israel; David Caballero from MeteoGrid, Spain; Inês Cardoso Oliveira, Carlos Viegas Damásio, João Moura Pires, Diogo Lopes and Gonçalo Prates from Universidade Nova de Lisboa, Portugal; Marielle Jappiot, Eric Maillé and Anne Ganteaume from INRAE and RECOVER, France; Samuel L. Manzello from Tohoku University, Japan and Reax Engineering, USA; Bruno Guillaume and Eric Guillaume from Efectis, France; Kuibin Zhou from Nanjing Tech University, China; Sayaka Suzuki from Tokyo Institute of Technology, Japan; Elsa Pastor, Pascale Vacca, Eulalia Planas and Alba Àgueda from CERTEC, Universitat Politècnica de Catalunya, Spain; Kim Donghyun from Jeonju University and the International Institute of Applied Systems Analysis, South Korea; Greg Baker from Fire Research Group Limited, New Zealand; Greg Penney from Fire and Rescue NSW, Australia; and Jacquelyn R. Chase from California State University–Chico, USA.

Scientific perspectives on wildfire risk management at the WUI property scale: Summary

The Forest Fire Research Centre of ADAI published a new open-access book on WUI property-scale wildfire risk management.

CTIF reported that the book features contributions from 34 researchers in 10 countries.

The lead coordinator of the volume is Miguel Almeida of the University of Coimbra.

Jack Cohen of the US Forest Service contributed the preface.

The book explains that ignition resistance in the Home Ignition Zone is essential to community wildfire protection.

Cohen stated that most home losses are caused by embers and local conditions, not fire fronts.

The book covers WUI characterisation, structure vulnerability, and fire modelling.

It also addresses regulation, insurance, and citizen involvement in wildfire prevention.

The conclusions call for more inclusive strategies, beyond traditional firefighting responses.

Researchers from universities, research institutes and fire services contributed to the book.

The book is available to download for free from the University of Coimbra’s press.