California needs to rethink its urban fire strategy

A wildfire in Wrightwood, California, in 2016. Image: Getty.

In October, we witnessed the wind-driven Tubbs fire blast its way through densely urbanised neighborhoods in Northern California, causing dozens of fatalities and thousands of home losses. This tragic event easily ranks as the most catastrophic fire in modern California history. Stories of how fast the fire spread and how little time people had to evacuate are stunning.

Despite how unusual the devastation appears, we need to recognise that these structure-to-structure “urban conflagrations” have happened in the past and will happen again. Yet these fires revealed that we have key gaps in our policy and planning related to assessing risk in fire-prone environments.

What is increasingly clear to fire researchers like me is that losses on the human side are often driven by where and how we build our communities. This means we must learn to coexist with fire, if we are going to inhabit fire-prone landscapes, just as we adapt to other natural hazards. An essential step is to shift our perspective from a focus on hazard to one that more comprehensively includes human vulnerabilities.

Mapping risk

California is leading the way in mapping the danger that wildfires pose to human communities and, in particular, linking building codes to fire severities that may be expected in given location. The state’s Fire Hazard Severity Zone maps are an essential step in recognising fire as an inevitable process that must be accommodated, similar to how we plan for floods, landslides, earthquakes and hurricanes.

What is missing from these maps, however, is extreme weather patterns. The Santa Ana winds of Southern California are a notable example. Strong, hot and dry wind episodes are associated with nearly all of our largest and most destructive wildfires, including the 1964 Hanley fire in Northern California that burned an almost identical footprint to the Tubbs fire, yet relatively little is currently known about how often they occur across a landscape.

 

Updating maps on fire risk should inform urban development. Image: Cal Fire/creative commons.

 

New methods are becoming available for mapping and modeling winds, and future versions of the Fire Hazard Severity Zone maps will therefore include such weather conditions. Similar maps are also needed for fire-prone areas outside California.

Despite technical advances, a key problem with most mapped approaches to fire danger is that the focus is almost exclusively on characterising the hazard – flame lengths, rates of spread or fire intensities of an oncoming wildfire – and much less on the vulnerabilities of what is actually exposed. The “wildland-urban interface,” where developed lands are exposed to natural, flammable areas, is thus often mapped and assumed to be where the exposure ends.

Clearly this is not always the case. Analogous to when a levee fails, after a wildfire manages to ignite homes along the wildland-urban interface, many homes farther inside the neighborhood can quickly become exposed.

Depending on the building codes in place during their construction, these newly exposed structures may or may not be very fire-resistant. Their vulnerability to ignition can also be especially high if they are spaced closely together and the winds are strong, because that is when fire spread transitions to a structure-to-structure domino effect.

Better fire risk mapping means we should be able refine our notion and approach to assessing vulnerability.

Reducing human exposure

There are numerous reports of how difficult and deadly it was to evacuate during the Tubbs fire. Apparently many people had almost no warning at all. This highlights the importance of both evacuation planning and evacuation communication systems, as getting out in time is what Americans tend to rely on in wildfire situations.

Although evacuation preparedness is nearly always mentioned in Community Wildfire Protection Plans and standard guidance for home owners, the overriding message is typically to “leave early” whenever possible.

While absolutely correct, this advice minimises the importance of pre-fire evacuation planning and the short time there may be to get out. It takes quite a bit of thought and effort to anticipate being in such a crisis situation.

What should one take, and where might one actually go?

On short notice, how does one account for pets, children or the elderly?

Is there a place one should retreat to, if evacuation orders are received too late or not at all?

This last question may be the one that gets the least attention, and the many fatalities in the Tubbs fire suggest that it requires much deeper consideration. Firefighters are often given specific training about what to do with limited evacuation options. For homeowners, however, guidance can be sparse.

When it is too late and too dangerous to evacuate safely, fallback options must be considered and communicated ahead of time. In an urban conflagration situation, local details dictate whether “safety zones” actually exist as places to take refuge. Given the real potential for such disasters, many communities should consider identifying (or building) key “hardened” structures to act as local-scale refuges.

Reducing human exposure involves more attention to what people must do during a wildfire, or even the rare urban conflagration. Safe evacuation deserves as much emphasis as reduction of fuels, such as creating defensible space around homes or larger scale fuel breaks by thinning vegetation around communities.


A safer built environment

From the scale of individual home construction up to the location and arrangement of development on a landscape, our communities should be better able to survive the natural hazards that occur there. This requires both short- and long-term strategies for achieving a safer built environment.

As a starting point, we must acknowledge that we currently have tens of thousands – possibly even hundreds of thousands – of homes constructed according to building codes that leave these structures vulnerable to ignition. Amazingly, however, there are very few examples of grant programs to mitigate such vulnerabilities through retrofit programs to, for instance, replace wood shake shingle roofs or to upgrade attic and crawlspace vents to block embers from entering homes.

In contrast, there are millions of dollars in public funds spent annually on community-scale fuel reduction projects. These are common activities pursued by Fire Safe Councils in California and similar organisations in other states.

The same level of support should be available for mitigation of fire-related structure vulnerabilities as there is for hazards.

Over the long term, land use planning is probably the most effective tool available for creating safer communities. We must be more deliberate about how we develop on fire-prone landscapes, taking advantage of emerging hazard-mapping techniques.

The goal here is not necessarily to build fewer homes, but to design and site developments that avoid the highest hazard regions and concentrate development in the lowest hazard areas. This logic applies, to varying degrees, to constraining development with respect to other natural hazards.

Despite an aversion by some to land use planning, this strategy is simply common sense. It will also save lives and massive amounts of public resources over the long term.

Where we do choose to develop and inhabit hazard-prone environments, it may be necessary to design communities with “passive survivability” in mind, or the ability to withstand the event and have water and power for a few days. This provides both the built environment and the people within some basic protection for a limited time.

The ConversationStrategies exist to lower the risk of fire in the current housing stock and to more carefully design and site future development where wildfires are possible. With increasing extremes expected as climate continues to change, officially recognising this link and creating a safer built environment will only become more urgent.

Max Moritz, Cooperative Extension Specialist, Wildland Fire, University of California, Berkeley.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Wild boar are moving back to Genoa, and not everyone is pleased

A wild boar, c1933. Image: Getty.

Crossing the Ponte Gerolamo Serra in the Italian city of Genoa, I spotted a small crowd clustered by the river wall. I approached, intrigued, and peered over the wall to discover the subject of their delight: a sounder of eight wild boars – the adults sheltering from the heat in the undergrowth, while the juveniles foraged among the foliage that grows in the river bed during the dry summer months.

In any other city, such a sight might have been surprising. But in Italy, and particularly in the region of Liguria, where Genoa is located, the population of wild boars has been increasing at such a rapid rate that these incidents are now common. Across the country, it’s estimated that the population has risen from 600,000 to 1m over the past decade.

But while wild boars may look comically out of place trotting about the city, it’s actually a natural result of the way people have migrated – and the wars they have fought – over the course of recent history.

Making a comeback

A species native to Europe, the wild boar (or “cinghiale”, in Italian) largely disappeared from its historical territories during the 18th and 19th centuries. Their decline was widely attributed to the combined effects of habitat change, competition for space and resources and, of course, hunting.

Wild boars were a prized quarry, revered for their ferocity – and the danger involved in pursuing them. According to local folklore from the region of Liguria, the last truly wild boar was hunted and killed in 1814, in the province of Savona.

After an absence of more than a century, wild boar began to return to Liguria, and to the neighbouring region of Piedmont. A further influx occurred during World War I, when it’s believed that military activities in the south-east of France forced parts of the population back into Italy over the Alps.

Although hunting fraternities were quick to augment this fledgling population with wild boars transported from elsewhere, the return of the species was primarily due to natural causes. From the 1950s onwards, traditional agricultural practices were abandoned as more and more people moved from rural towns into the cities. This meant that large areas of formerly cultivated terraces and pastures were rapidly overgrown, fast becoming dense secondary woodlands.

A city gone wild

This spontaneous “rewilding” has become a controversial issue in the region. Many conservationists and environmental organisations consider the region’s return to a “wild state” a success. But others believe that the encroaching wilderness signals a loss of traditional woodland knowledge and a reduction of biodiversity, associated with the pastures and meadows.


The province of Genoa is among the areas most densely populated by wild boar in Italy, with an estimated 25 boar per 10km². Rewilding processes have brought woodlands to the city limits, blurring the boundary between rural and urban areas. The species has expanded beyond the hinterlands, colonising highly urbanised, densely populated city spaces in Genoa, drawn by the abundance of food waste created by humans.

In 2009, the infamous boar Pierino made his home at Righi, on the outskirts of Genoa, where he was routinely fed with focaccia by enthusiasts. Today, a family of wild boar call the Albergo dei Poveri – a historical hostel for the Genoese poor in the city centre – their home.

But while their antics are often recorded and shared with glee on social media, the threats posed by the presence of wild animals has become a preoccupation for the city’s municipal administration.

Boorish behaviour

Wild boar have been involved in a number of traffic accidents, and have proven to be particularly dangerous when with their young, attacking dogs and even people. The city council in Genoa has put forward many proposals to reduce the number of animals in the city, ranging from forced removals, to sterilisation, increased attention to waste disposal and approved hunts. About 90 wild boar were reportedly culled in 2018.

Needless to say, each of these measures has been hotly debated. Animal advocacy groups staunchly oppose the proposals, and sometimes obstruct the authorities’ attempts to take action, often sending patrols to care for the animals, and even give them names. But other residents are displeased with the animals’ presence in the city, and have consulted with the council on how to address the problems that they cause.

And so Genoa continues to grapple with thorny issues surrounding the presence of wild boar in the city, with the city authorities seeking to resolve a polemical issue that embroils the lives of animals and humans alike. So far, a collective, coherent and communally agreeable strategy has proven evasive; one that considers the need for public safety, hygiene and health with the ethical responsibilities towards to wild boar themselves.

Meanwhile, the animals themselves continue to lounge and forage beneath the Ponte Gerolamo Serra and elsewhere, bringing a little of the wilderness into the city.

The Conversation

Robert Hearn, Assistant Professor in Human Geography, University of Nottingham.

This article is republished from The Conversation under a Creative Commons license. Read the original article.