Vulnerability, Management of Volcanic Risk and Neoliberalism in Colima

2020 ◽  
pp. 213-242
Author(s):  
Hugo Ignacio Rodríguez-García
2021 ◽  
Author(s):  
Blaise Mafuko Nyandwi ◽  
Matthieu Kervyn ◽  
François Muhashy Habiyaremye ◽  
François Kervyn ◽  
Caroline Michellier

<p>The city of Goma is located in the eastern region of the Democratic Republic of Congo. With around one million inhabitants, it is built on lava flows, 15 km south of the active Nyiragongo volcano. Historically, the town was affected twice by eruptions, in 1977 and 2002 and severe destructions were reported. At that time, no volcanic risk preparedness and management tools had been implemented, and communication during and after the eruption was not consistent enough to avoid panic and human casualties. Without an appropriate and accurate risk communication, people may adopt a behavior which can put them at risk, by increasing their vulnerability. Nineteen years after the last disaster, risk management still have to develop an effective risk preparedness strategy and integrate risk awareness raising tools. The aim of this ongoing doctoral research is the assessment of risk culture, building upon a risk perception assessment and identification of risk reduction measures to be enhanced.</p><p>A survey of 2224 adults among the general population of Goma was conducted in eight representative neighborhoods in order to assess the risk perception, the experience of the risk communication as well as the risk preparedness of inhabitants. We here present a first analysis of the results regarding the risk communication challenges. Goma is a dynamic town with a young population (80% are under 45 years old), living in relatively poor and large family (51% of households have 4-7 members and 31% 8-11 members; 57% of household have an income between 0-250$), with rather low education (47% is secondary level and 34% graduated). Language is one of the volcanic risk communication challenges in Goma: apart from French as the official language, Swahili as local, and English imposed by the large humanitarian sector, there are many dialects. Moreover, most communication tools are informal (social networks, friends and relatives…) and inhabitants mostly look for information on religion (22%), health (15%) and politics (12%), but not so much about risk reduction. Local radio (24%), television (14,5%) and social networks (13%) are the most preferred information channels. The city of Goma is also very dynamic: with a high migration rate, the population is growing and renewing itself regularly, to the point that risk communication must take into account the newcomers in order to be efficient. Additionally, our survey shows that experience of disasters and trust in decision-makers also provide a basis for effective risk communication.</p><p>By presenting, as examples, the communication chain during the 2002 Nyiragongo eruption, as well as a more recent example of miscommunication due to the publication, in the general public press, of a scientific article with significant uncertainties in eruption forecast modelling (leading to misinterpretation by non-expert readers), we will demonstrate that the cascading reactions may have consequences putting risk decision-makers and scientists in a difficult position, by provoking a feeling of mistrust and doubt among the population. Based on the Goma case study, we will show that risk communication in the global south is a major risk management challenge with complex issues.</p>


2021 ◽  
Author(s):  
Noa Ligot ◽  
Benoît Pereira ◽  
Patrick Bogaert ◽  
Guillaume Lobet ◽  
Pierre Delmelle

<p>Volcanic ashfall negatively affects crops, causing major economic losses and jeopardising the livelihood of farmers in developing countries where agriculture is at volcanic risk. Ash on plant foliage reduces the amount of incident light, thereby limiting photosynthesis and plant yield. An excessive ash load may also result in mechanical plant damages, such as defoliation and breakage of the stem and twigs. Characterising crop vulnerability to ashfall is critical to conduct a comprehensive volcanic risk analysis. This is normally done by describing the relationship between the ash deposit thickness and the corresponding reduction in crop yield, i.e. a fragility function. However, ash depth measured on the ground surface is a crude proxy of ash retention on plant foliage as this metrics neglects other factors, such as ash particle size, leaf pubescence and condition of humidity at leaf surfaces, which are likely to influence the amount of ash that stays on leaves.</p><p>Here we report the results of greenhouse experiments in which we measured the percentage of leaf surface area covered by ash particles for one hairy leaf plant (tomato, Solanum lycopersicum L.) and one hairless leaf plant (chilli pepper, Capsicum annuum L.) exposed to simulated ashfalls. We tested six particle size ranges (≤ 90, 90-125, 125-250, 250-500, 500-1000, 1000-2000 µm) and two conditions of humidity at leaf surfaces, i.e. dry and wet. Each treatment consisted of 15 replicates. The tomato and chilli pepper plants exposed to ash were at the seven- and eight-leaf stage, respectively. An ash load of ~570 g m<sup>-2 </sup>was applied to each plant using a homemade ashfall simulator. We estimated the leaf surface area covered by ash from pictures taken before and immediately after the simulated ashfall. The ImageJ software was used for image processing and analysis.</p><p>Our results show that leaf coverage by ash increases with decreasing particle size. Exposure of tomato and chilli pepper to ash ≤ 90 μm always led to ~90% coverage of the leaf surface area. For coarser particles sizes (i.e. between 125 and 500 µm) and dry condition at leaf surfaces, a significantly higher percentage (on average 29 and 16%) of the leaf surface area was covered by ash in the case of tomato compared to chilli pepper, highlighting the influence of leaf pubescence on ash retention. In addition, for particle sizes between 90 and 500 µm, wetting of the leaf surfaces prior to ashfall enhanced the ash cover by 19 ± 5% and 34 ± 11% for tomato and chilli pepper, respectively.</p><p>These findings highlight that ash deposit thickness alone cannot describe the hazard intensity accurately. A thin deposit of fine ash (≤ 90 µm) will likely cover the entire leaf surface area, thereby eliciting a disproportionate effect on plant foliage compared to a thicker but coarser deposit. Similarly, for a same ash depth, leaf pubescence and humid conditions at the leaf surfaces will enhance ash retention, thereby increasing the likelihood of damage. Our study will contribute to improve the reliability of crop fragility functions used in volcanic risk assessment.</p>


2021 ◽  
Author(s):  
Eddie Lazebnik ◽  
Eyal Traitel ◽  
Paul Wooderson ◽  
Douglas Ruddle

2013 ◽  
Vol 1 (2) ◽  
pp. 1081-1118 ◽  
Author(s):  
P. Gehl ◽  
C. Quinet ◽  
G. Le Cozannet ◽  
E. Kouokam ◽  
P. Thierry

Abstract. This paper presents an integrated approach to conduct a scenario-based volcanic risk assessment on a variety of exposed assets, such as residential buildings, cultivated areas, network infrastructures or individual strategic buildings. The focus is put on the simulation of scenarios, based on deterministic adverse events input, which are applied to the case-study of an effusive eruption on the Mount Cameroon volcano, resulting in the damage estimation of the assets located in the area. The work is based on the recent advances in the field of seismic risk. A software for systemic risk scenario analysis developed within the FP7 project SYNER-G has been adapted to address the issue of volcanic risk. Most significant improvements include the addition of vulnerability models adapted to each kind of exposed element and the possibility to quantify the successive potential damages inflicted by a sequence of adverse events (e.g. lava flows, tephra fall, etc.). The use of an object-oriented architecture gives the opportunity to model and compute the physical damage of very disparate types of infrastructures under the same framework. Finally, while the risk scenario approach is limited to the assessment of the physical impact of adverse events, a specific focus on strategic infrastructures and a dialogue with stakeholders helps in evaluating the potential wider indirect consequences of an eruption.


Author(s):  
Nkemdilim Maureen Ekpeni ◽  
Amidu Owolabi Ayeni

This chapter examines both concept of global hazard and disaster and its management in the lights of its vulnerability. It categorized the different types of hazards and disasters and their components. From the research findings, it is observed that hazards and disaster are two sides of a coin. They occur at the interface between human systems and natural events in our physical environments. This chapter highlights that the major environmental changes driving hazards and vulnerability to disasters are climate change, land-use changes, and degradation of natural resources. After presenting a typology of disasters and their magnitude globally, management of disaster has transited from just being a “response and relief”-centric approach to a mitigation and preparedness approach.


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