Risks revealed by cartography – cartography renewed by the geovisualization of risks

In this thematic issue, the International Journal of Cartography explores the renewed relationship between the representation of risks and cartography or mapping.

First and foremost, risk mapping can be defined by maintaining the objectives that it has set itself; i.e.: analysing, representing and interrogating risks as far as their spatial characteristics are concerned. Today, as far as regional planning is concerned, risk mapping is a major element in terms of tools in the form of regulatory mapping. In this case, maps represent risk-generating phenomena, often in the form of natural, industrial, epidemic or other hazard zones. The risk can be approached in greater detail by combining regions’ hazard zones with maps covering human, material, economic or environmental issues.

But, between theoretical approaches and recent and present explorations in risk management, a new dialectic is being invented, which leads us to formulate the following hypothesis. Even if most of the techniques and processes observed in the maps produced are not really innovations, the present period is characterized by a certain number of phenomena liable to lead to serious reconsideration of the traditional mapping model based on specialists’ production (cartographers) of the occurrence of a phenomenon and its impacts.

Directly or indirectly, several factors lead us to put forward this hypothesis. The first factor concerns the uncertainty liable to tarnish modelling of phenomena in a context of climate change. Like representation, risk management is discovering new challenges caused by uncertainties concerning the frequency, intensity, dynamics or even the timescale of extreme natural phenomena.

Linked with the difficulties in characterizing phenomena (Barroca, Bernardara, Girard, & Mazo, 2015), the second factor concerns the increasing complexity of urban systems and their high levels of interdependence. Dysfunctions in services provided by critical infrastructures (Fekete et al., 2015) such as energy or transport (article 13) and social and functional dependence lead to changes in terms of spatial risks. Impacts become difficult to understand and the traditional approach to risks by combining the risk spatially with vulnerability (Bonati & Mendes, 2014) is becoming highly uncertain, as shown by the difference between the forecasts and the impacts made by events on both functional and economic aspects (Mitchell 1999).

Symmetrically, the increasing development of the resilience notion enables a risk to be envisaged in a different form that provides more room for crisis and post-crisis management (November & Leanza, 2015). The potential dynamics characterized by this new expression (Serre & Barroca, 2013) need to be clarified to allow us to make progress in handling risk situations. Even if the interest of the notion seems to be clear, it must be noted that actions for assessing the many different forms, scales, timescales and the cartographic implementation of the concept together with its applications continue to be few and far between. By way of the resilience concept (Serre, Barroca, & Laganier, 2013), risk can also be conceived from points of view of population evacuation, degraded modes of operation in territories and society, together with reconstruction and positioning the event in a historical series. Resilience is dynamic and integrative by nature and the whole of society is actively involved (Oliver, Thomas, & Thompson, 2014). Therefore, mapping concerns a large number of actors. It is not just the representation of a phenomenon designed for specialists but should become a support for shared collective decisions made for meeting a common goal (Serre & Heinzlef, in press). Making a better definition of risk representations, mapping resilience options, strengthening response dynamics via specific maps co-produced by target actors and understanding restrictive urban systems will enable decision-making to be enriched and new strategies to be deployed. These strategies plan operations on a broad basis but leave more room for new actions to emerge and for initiatives to be taken (Dauphiné & Provitolo, 2013). How can we go from strategies and mapping processes that are based on protection on the one hand and reducing vulnerability on the other, all in respect of specific hazards, towards new representations aimed at reinforcing areas’ capacities of response? What contributions can be made by mapping for adapting to multiple events, no matter whether they be catastrophic or modest, but more frequent? How can mapping provide input for decision-making and action processes needed for local capacities and self-organization?

The contributions brought together in this issue throw light on this dialogue via the research carried out in different continents, multi-disciplinary research and research on different situations and on different scales with various hazards and which are related to different types of end-user.

This special issue brings together questions on the relationships between risks, geovisualization, improving decision-making processes based on space, or even territories’ resilience strategies.

In this respect, four articles focus on important questions in terms of resilience today: evacuation of populations before or during a major event (Girres, Leone, Péroche, Gustave, and Gherardi, 2018; Palka, Serrhini, and Andrieu, 2018; Van Kerkvoorde, Kellens, Verfaillie, and Ooms, 2017; Sharma, Mishra, Bhatt, Rao, and Bhanumurthy, 2017). In these articles, the issue at stake consists of producing evacuation maps for informing and training populations in the face of feared hazards. For example, Girres et al. (2018) suggest drawing up consensual rules concerning specific symbolization dedicated to evacuation when faced with a tsunami. The result is an effort to harmonize rules of symbolization, whose effects are being tested and discussed, notably, on experimental sites in the Caribbean and the Mediterranean. Van Kerkvoorde et al. (2017) also tackle the question of evacuation using a participative or cooperative approach, whose aim is to create evacuation maps when facing flood risks in Europe. At every stage in cartographic production, actors’ specific characteristics are included for optimizing the production of evacuation maps. In the third article, on the basis of multi-player input, Palka et al. (2018) question the differences in cognitive perceptions of the same map (the case of evacuation maps) and their effects on behaviour and strategic decisions. Lastly, Kumar Sharma et al. (2017) also focus on evacuation mapping in the face of flood risks, this time in India, with the ambition of changing from static mapping to automatic, operational mapping by developing a specific Web SIG, based on creating a library devoted to visualizing risks.

The last two articles aim at making a representation via a map of risk histories related to rail infrastructures for improving anticipation of future risks (Saint-Marc, Villanova-Oliver, Davoine, Capoccioni, and Chenier, 2017), and to developing a new form of risk mapping based on the resilience concept (Propeck-Zimmermann, Saint-Gérand, Haniotou, and Skrimizea, 2018). In the case of the historical approach (Saint Marc et al., 2017) to risks linked with SNCF (French railway system) infrastructures, a risk geovisualization interface has been developed. Repeated events for a given infrastructure can also be represented with this interface and cascade effects can be understood. Lastly, (Propeck-Zimmermann et al., 2018) develop risk visualization based on two resilience factors: absorption and the return to a new balance. The proposed approach has the merit of covering the systemic complexity of areas subject to risk.