Geology for Global Development


HFA2: Let’s define what we mean by ‘multi-hazard’…

B9KzAAMIQAA8hbvFrom 14-18th March, disaster professionals, politicians and other stakeholders will be gathering in Sendai (Japan) at the UN World Conference on Disaster Risk Reduction (WCDRR). The aim of the meeting will be to agree upon the final text to replace the Hyogo Framework for Action, the UN guidelines for action on disaster risk reduction and strengthening resilience.

Today’s post, adapted from a post originally published on the official WCDRR blog page, picks out the key phrase ‘multi-hazard’ and calls for it to be better defined and understood…

The term ‘multi-hazard’ is widely used, featuring in both the Hyogo Framework for Action and the zero draft of the post-2015 framework for Disaster Risk Reduction. You can also find it other UN and UK Government documents, and in the academic literature. While ‘multi-hazard’ approaches are widely encouraged, it is not common for the term to actually be defined. It is now being used in different ways, by different people, leading to confusion in the natural hazards and disaster risk communities.

Why does it matter?

Multi-hazard approaches are essential; failing to understand the whole natural system (rather than a small portion of it) can distort management priorities, increase vulnerability to other spatially relevant hazards or underestimate risk. Imagine a community impacted by earthquakes, landslides and volcanic eruptions – decisions need to reflect the differential hazard potential and risk from each of these, not just focus on one of them. The consequences of focusing on one only are that actions taken may increase people’s vulnerability to other hazards.

The promotion of ‘multi-hazard’ approaches, therefore, is to be welcomed, but these need to be more than just multiple ‘single-hazard’ approaches. Some groups use the term ‘multi-hazard’ to describe the independent analysis of multiple different hazards (e.g., landslides, earthquakes, volcanic eruptions, flooding) relevant to a given area. Others use the term when referring to the superimposition of various GIS layers to identify areas of spatial overlap. These approaches can be thought of as the collation of multiple ‘single-hazard’ analyses, where we seek to understand the discrete risks due to multiple natural hazards.

A further group, including myself and others, argues that a true multi-hazard approach should recognise that hazard processes are not independent. Multi-hazard approaches should include both an examination of multiple different hazards but also recognise the significant interactions between these hazards. As research shows, triggering and increased probability relationships are widespread between natural hazards, with hazard cascades an important consideration for those interested in multi-hazards. For example, an earthquake may trigger hundreds of landslides, some of which may block rivers and result in flooding, causing erosion at the foot of slopes and triggering further landslides. Furthermore, impacts deriving from the concurrence of two (or more) hazard events may be greater than the sum of components. For example, the spatial and temporal overlap of a volcanic eruption and tropical storm event may result in much more severe flooding than would have occurred otherwise, due to the blocking of drainage systems by volcanic ash.

A practical call for action…

The UNISDR has definitions for key terminology including hazard, geological hazard, hydrometeorological hazard and biological hazard. It is surely time for a clear definition of what is meant by ‘multi-hazard’, if this important but poorly-understood phrase is to be included in any text coming out of the Sendai process. The focus of research and mitigation tools has to adapt from multiple ‘single-hazard’ analyses to true ‘multi-hazard’ studies.

RevGeophysImageMore information about hazard interactions and their integration into a clearly defined multi-hazard assessment can be found in this recent review paper (open-access). Chapter 7 includes a possible ‘working definition’ or framework for a multi-hazard assessment.

Field Research in Guatemala (4) – Reflections from Fuego


Small eruption of Fuego, Guatemala (Credit: Joel Gill, 2014)

Small eruption of Fuego, Guatemala
(Credit: Joel Gill, 2014)

Joel Gill (GfGD Founding Director) continues his live reporting from Guatemala, discussing his interdisciplinary field research relating to natural hazard interactions and disaster risk reduction. This fieldwork forms part of a NERC/ESRC funded PhD, supervised by staff in the Department of Geography at King’s College London.

Over the past few weeks I’ve had the opportunity to see some remarkable things in Guatemala. The most special but also poignant time was around the Volcano Fuego. This location rapidly became my favourite in Guatemala, and for a number of a reasons a place I can’t get out of mind. In today’s post I reflect on some personal feelings – touching on both the incredible beauty of volcanic activity but also the serious danger that these phenomena can cause to vulnerable communities, and our responsibility to support disaster risk reduction.

Let me set the scene, we get up and set of at around 7.30am – driving for a couple of hours around and then up the side of a volcano, Acatenango. After parking up, we put our backpacks on, admire the stunning view across the plain of the volcano Agua and set off on a long walk. This trek takes us around the side of Acatenango so as to get a view of the active volcano, Fuego.


Small eruption of Fuego, Guatemala
(Credit: Joel Gill, 2014)

When the volcano came into sight, we were greeted with a loud explosion of noise and the firing of material (mainly gas, ash and rock material) into the air. This was my first sight or experience of an erupting volcano. It was relatively gentle activity, these blasts normally occur at Fuego several times each day at the moment. Shortly afterwards the volcano grumbled again and more material was ejected into the air. This happened a third, fourth, fifth time… and more. Seeing something so close, and hearing the intensity of the bang and the amount of material ejected – and yet also appreciating how small the eruption was compared to the kinds of eruptions that demand mass evacuations was quite poignant. During a serious eruption, the noise and volume of material must be phenomenally scary to encounter.

Volcanoes are remarkably beautiful by day, but at night they are simply stunning. Arriving at the Fuego Volcanic Observatory I was designated an open air bed in the back of a pick-up truck. This turned out to be the best bad night’s sleep I’ve ever had. My view for the night would be Fuego. The observatory is located on the other side of the volcano to the views we’d got by day. Once dark, and with a clear night, each explosion sent out of the volcano a blast of red-hot rock, as well as gas and ash. The peak of the volcanic cone glowed red as very hot ‘volcanic bombs’ fired into the air and rolled down the volcano at tremendous velocities. These small eruptions elicited genuine awe and amazement… it was a truly unforgettable evening.

Seeing these sights was an incredible privilege as a geologist, a hazards researcher or just as someone with a love of the natural environment. But the chance to see these things also comes with a stark reminder that I almost certainly won’t be next to the volcano when it next explodes with the huge power that may kill many people. This was hammered home the following day, when we visited sites of recent lahars and pyroclastic flows – two hazards associated with this volcano.

2012 Lahar Deposits, Fuego, Guatemala (note the destroyed road in the background) (Credit: Joel Gill, 2014)

2012 Lahar Deposits, Fuego, Guatemala (note the destroyed road in the background on the left)
(Credit: Joel Gill, 2014)

Lahars are generated when rain mixes with sediment created by the volcanic eruptions. They move with great speed and power, carrying huge amounts of material with them. In 2012, after a larger eruption of Fuego, a number of lahars were generated in the rainy season carrying with them material that had formed a pyroclastic flow down the volcano. These lahars impacted an area with little previous experience of lahars, and destroyed a crucial road in the process. The loss of this road now means that communities are isolated from their villages – making evacuation in the event of a large eruption very difficult. The lahar deposits include a range of particle sizes, from fine sediment to huge boulders. As such driving across them is far from straightforward.

Lahars themselves are very dangerous, and have been responsible for major fatalities around the world in the past. They also trigger further hazards (e.g. flooding) downstream. In this location, they have significantly increased the vulnerability of an already vulnerable community. When the next large eruption takes place, people will need to evacuate. Many won’t and many won’t be able to. Those who try are going to face the additional significant difficulty of trying to cross lahar material. If this was in the middle of rainy season, any attempt to do so would almost certainly be impossible or perhaps fatal. People could try finding another route, but in a large vulcanian eruption the volume of ash means it can be very difficult to see more than 1-2m in front of you. Attempts to evacuate by routes other than those closest would be difficult. In one other location around this volcano, evacuation is only possible via a narrow rope bridge.

Seeing this location, and talking to people about it during my research interviews afterwards, was really sad. Seeing the genuine desire of people to help, a real heart-felt concern – but an inability to do anything due to an all too common problem of lack of funding. More bridges, evacuation routes and shelters can’t be built as they cost money. Even if those were in place, poverty means some people may choose not to leave as they don’t want to risk losing their property or assets. Others can’t leave due to disability, illness or age.

I feel incredibly privileged to have seen Fuego by day and night, climbed close to its summit and marvelled at one of nature’s most beautiful sights. I also feel a huge weight of responsibility and a strong desire to utilise the skills, the knowledge, the contacts, the resources that I have available to address some of the injustices that currently mean that a large future eruption of Fuego could result in a significant disaster event – education, an ability to evacuate safely and rapidly, a reduction in poverty, access to insurance schemes that will help people feel safer leaving their property, better monitoring equipment for the volcanic observers.

When I leave Guatemala on the morning of the 17th March I’ll be leaving with the communities around Fuego in my mind and a determination to use those resources available to me to serve them through strengthening disaster risk reduction.

Field Research in Guatemala (1) – Introduction

Joel Gill 1Over the next couple of months, Joel Gill (GfGD Founding Director) will be reporting live from Guatemala, whilst undertaking interdisciplinary field research relating to natural hazards and disaster risk reduction. This fieldwork forms part of a NERC/ESRC funded PhD, supervised at King’s College LondonToday Joel gives an introduction to his research and why he is focusing on the Central American country of Guatemala… 

Many assessments of natural hazard potential treat natural hazards as discrete or independent events. An examination of multiple case studies and a broad range of hazards literature suggests that this is not always appropriate. Initial results of research that I have conducted at King’s College London (KCL) with Professor Bruce Malamud, identify a broad range of natural hazard interactions (more than 90 interactions, across 21 different natural hazards, paper in review). This discrepancy between observed reality and the modelling of hazard potential could result in an underestimation of risk or a distortion of management priorities.

Research Aims

My interdisciplinary PhD research therefore, aims to develop and improve multi-hazard approaches to assessing hazard potential, through increasing our understanding and characterisation of natural hazard interactions (e.g., an earthquake triggering landslides) and networks of interactions (e.g., an earthquake triggering landslides, which trigger flooding, which trigger further landslides) at global and local scales.

The fieldwork component of this work aims to explore, quantify and contrast hazard interaction networks developed from understandings and data populating contrasting knowledge worlds. In other words, what differences are there in the understanding of hazard interactions between hazard professionals and local community groups? What implications do these contrasts have on hazard monitoring, policy and research priorities? Feedback  will also be gathered to enhance a series of visualisations developed in earlier stages of this work, and designed for end-user stakeholders.

Guatemala (Public Domain)

Guatemala (Public Domain)

Why Guatemala?

Guatemala is a country prone to multiple natural and environmental hazards, including earthquakes, tsunamis, volcanic eruptions, landslides, floods, droughts, ground collapse, tropical storms and hurricanes, significant temperature variations, wildfires and impact events. Furthermore, development places a number of stresses on the natural environment (including deforestation and urbanisation). These stresses have been documented to exacerbate a range of natural hazards in the area (e.g., deforestation exacerbating landslides during Hurricane Mitch, or road cuttings increasing landslides after an earthquake in 2012).

The existence of a broad range of natural hazards alone is not sufficient for this study. In addition to this, we are interested in the spatial overlap of natural hazards and the interactions between them. Multiple case studies have been recorded of hazard interaction networks in Guatemala, with triggering, increased probability and synergistic hazard relationships all featured.

This combination of factors make Guatemala an ideal country to examine the existence of hazard interactions and the understanding of such processes by key stakeholders. I will be travelling there from January 16th until March 17th.

What kind of work will you be doing?

Over the two months I will be in Guatemala, I will be undertaking:

  1. A ground reconnaissance of the hazardscape (observing both natural and anthropogenic environments at multiple scales, and having discussions/semi-structured interviews with relevant stakeholders.
  2. A series of interviews and workshops with hazard professionals and local communities to assess their understanding of hazard interactions and how these understandings are developed.
  3. Personal training and development (including language training, joining MSc Volcanology students from the University of Bristol for a field course, and learning lots more about social science field methodologies).

Over the next couple of months I will try and write regularly, covering my fieldwork experiences and lessons learnt throughout different stages of the work. I’m sure I will be touching on aspects of traditional geology, hazard processes and impacts, the integration of social science techniques into field research and issues of cross-cultural communication.

You can leave questions about Joel’s preparations and experiences in the comments section below, or via Twitter (@Geo_Dev//@GillJoel).

Typhoon Haiyan

We were extremely saddened to hear at the end of last week and over the weekend about the destruction brought by Typhoon Haiyan, impacting the Philippines last week and (at the time of writing) moving towards Vietnam. The event caused widespread damage, with reports suggesting thousands of deaths and an order of magnitude more displaced. The impact on communities through loss of livelihoods and homes cannot be overestimated.

The disaster in the Philippines is an example of a multi-hazard event, where a disaster is not composed of one hazard, but is a function of a number of cascading or concurrent hazards. An enormous storm event (Typhoon Haiyan) triggered lightning, flooding and many landslide events – as well as a large storm surge. The disaster is a function of the vulnerability of communities, which is a highly dynamic factor. Last month an earthquake struck the Philippines causing damage to the Bohol region. Individuals and groups impacted by this earthquake are likely to have been had an increased vulnerability to future events occurring shortly after the earthquake (such as this Typhoon). An effort was made to move those impacted by the earthquake and still living in tents, to more secure accommodation. As is so often the case with multi-hazard type events, the impacts are much greater than the sum of their parts.

A huge relief effort is now underway, with many of the major international charities launching appeals to help those most affected. We will be carefully watching the situation and sharing any key updates on our social media. You can also find more helpful information on the sites noted below.

Further Reading

Relief Web – A collection of articles on the disaster, regularly updated.

Guardian Natural Disasters – General Event Commentary and multiple articles

The Landslide Blog (Professor Dave Petley) – Landslides and Typhoon Haiyan

Disasters Emergency Committee – Relief Effort Information