Natural Hazards

Risk management

The bad, the good and the unpredictable: living with volcanoes / part 2

The bad, the good and the unpredictable: living with volcanoes          / part 2

Before continuing, if you haven’t read it yet, catch up with the first part of this blog article by clicking on this link.

The good

Living with volcanoes is not all bad. Volcanoes provide a wealth of natural resources in the form of building materials, hot springs, freshwater and fertile soil. However, there are more hidden aspects, which was the focus of a recent collaboration with an archaeologist. We believe that volcanoes and their landforms provide “cultural services”, which is a component defined by the UN Millennium Ecosystem Assessment as the cultural benefits we gain from ecosystems. These components are the following:

[Read More]

The bad, the good and the unpredictable: living with volcanoes / part 1

The bad, the good and the unpredictable: living with volcanoes     / part 1

Humans have existed and lived alongside volcanoes for as long as we have been on the planet. For some, this has been beneficial and often, in fact, we can see how indigenous knowledge finds a sustainable approach living with them. However, in some cases, societies cannot cope and are overwhelmed with volcanic eruptions. 

There are many examples from archaeological studies dealing with how ancient civilisations, successfully or unsuccessfully, lived with volcanoes. On one hand, for example, Pre-Colombian villages in Costa Rica were found to be the most resilient to the eruptions of Arenal volcano, managing to cope and survive with many eruptions. The villages were simple societies with egalitarian rules (where people are viewed as having equal rights and opportunities). This meant that they coped faster because everyone had the same duties and rights and were able to help each other without waiting for a ruler to do something for them. On the other hand, more complex chiefdoms in Central America struggled to cope with these events as they had a greater reliance on the built environment, competitive and sometimes hostile political environments and greater population densities [1, 2]. 

[Read More]

How can remote sensing and wavelet transform unravel natural and anthropogenic ground motion processes?

How can remote sensing and wavelet transform unravel natural and anthropogenic ground motion processes?

Underground energy storage and gas storage in aquifers

In the context of energy transition, massive energy storage is a key issue for the integration of renewable sources into the energy mix. Storing energy in the underground can lead to larger-scale, longer-term and safer solutions than above-ground energy storage technologies. In particular, natural gas storages are designed to address different needs, like a strategic natural gas reserve, the regulation of gas supply and the answer to a seasonal peak heating or electricity demand. Energy companies routinely store gas in underground reservoirs known as “gas aquifers”, which then become gigantic natural tanks for injecting and extracting gases for energy needs. The natural gas is compressed and injected through wells into selected reservoirs, usually constituted of sand layers containing water, which is automatically forced out. The gas is then extracted from the same wells and the water can naturally flow back into the sand, maintaining equilibrium. Natural gas is stored from May to September when the demand is lower and withdrawn from October to April when the demand is higher.

Figure 1 – Location map showing a Sentinel-1 acquisition (2016) in Southwestern France (Aquitaine Basin) (colour image), a 25 km cell used by SMOS satellite (black square) that contains the reservoir isobaths of a gas storage site (red lines).

Integrated monitoring of a gas storage site

For risk prevention and environmental protection purposes, it is essential to check the integrity of the natural reservoirs used for underground storage and how they respond to the annual natural gas injection and extraction cycles. [Read More]

Our first Interview is ready!

Our first Interview is ready!

Today we are happy to post our first interview and to thank our first interviewee, Paola Crippa for her contribution. The topic focuses on mortality from high concentration of particulate matter generated from widespread wildfires. This topic wants to be just the starting point to address another and broader theme: dealing with lack-of-data for research purposes in developing countries.

This will be inspired by one of the most recent researches published by Paola: “Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia” http://www.nature.com/articles/srep37074


1. Which problem did you address in your research?

Vegetation and peatland fires occur frequently across Equatorial Asia, as they are used to manage the land, clear vegetation and to prepare and maintain land for agriculture. Wildfires emit pollutants that can cause poor regional air quality and are extremely harmful to human health. As a result, each year thousands of premature deaths occur across Equatorial Asia. In fall 2015, these fires burned out of control in Indonesia as a result of the extremely dry landscape caused by strong El Nino conditions. In our study, we use a state-of-the-art air quality model (the Weather Research and Forecasting model with Chemistry, WRF-Chem) at high spatial-temporal resolution to quantify the impact of these fires on air quality and human health. We found that 69 million people were persistently exposed to unhealthy air quality conditions caused by fire emissions and that this pollution may have caused 11,880 (6,153–17,270) excess mortalities. Our results emphasize the need of a coordinated effort between scientists and policymakers to assess the impact of land use changes and human-driven deforestation on fire frequency, to possibly mitigate the impacts of these hazardous events on human lives.

2. Do mortality estimates from simulations actually agree with the corresponding real data?

We evaluated our model simulations relative to both ground- and satellite-based observations of aerosol properties and we are confident that our simulated results provide a realistic representation of the 2015 wildfires, and hence can be used to infer the impact on air quality and human health. We integrated our hourly maps of pollutant concentrations with population density data and estimated the number of people persistently exposed to unhealthy and hazardous air quality conditions during fall 2015 with respect to World Health Organization and Pollutant Standards Index guidelines. While these metrics gave us confidence in our assessment of population exposure, it was unfortunately not possible to validate our mortality estimates since no local hospitalization data were available for the period of interest.

3. No real data were available? This is certainly a strong limitation for the research community but also for those that deal with risk management. What is your position in this regard?

In order to estimate the number of premature deaths occurred as a result of exposure to degraded air quality conditions, epidemiological evidence to link pollutant concentrations and hospitalizations and mortality data are needed. Unfortunately, in Equatorial Asia, as well as in most developing countries, these cohort studies have never been performed, or at least those data are not available to scientists. In our work, we used exposure-response functions developed from studies conducted in Europe and United States where pollutant concentrations are much lower than those registered during the events we studied. Therefore, our mortality estimates are likely conservative. This is indeed a big limitation not only for scientists but also for policymakers when trying to reduce the negative impacts of natural hazards since no robust evidence of the magnitude of those events is available. If local governments would be able to collect, organize and release these data, this would allow scientists to better serve the community by providing better mitigation strategies.

4. Do other countries invest more in data collection allowing for a better coupling between simulations and ground-truth data?

In Europe and United States, epidemiological studies linking exposure to mortality and, most importantly, hospitalization data are easier to access. While still not as easily accessible as most publicly funded satellite and climate model repositories, we hope that Western governments would implement a standardized national or international database that can be used to produce considerably more reliable exposure maps. This would allow a better assessment of mortality in polluted areas such as London, but the level of exposure in less developed countries is on a different level of magnitude, with millions of human lives at risk, including children and elderly citizens. Since any extrapolation of Western data in these areas is problematic, the international community must invest in the development of local studies and data collection.

5. Do you think that simulations like yours can be useful not only in a post-disaster phase but as a risk prevention tool? 

One of the great advantages of using numerical models such as WRF-Chem is that they can be also used in forecasting mode, meaning that they can be used to predict where and how fast pollution would be transported from emission sources and consequently provide information for reducing population exposure. They can be also used to make projections as a function of emission scenarios. This is particularly important in regions subject to rapid land use change and human-driven deforestation, such as Equatorial Asia or South America. An example of successful integration of numerical model forecasts with mitigation strategies can be found in Santiago de Chile, where the government declares alert days based on numerical weather model forecasts of unhealthy pollution. This is the result of a close and constructive collaboration between scientists and policymakers.