Introduction to the thematic issue “Applicable geomorphology: from natural processes to environmental and risk management” (proceedings of the 14th Young Geomorphologists Meeting)
The coordinators of this special issue want to thank all the members of the organization committee of the 14th Young Geomorphologists Meeting (Gilles Arnaud-Fassetta, Edouard de Bélizal, Marie Chenet, Etienne Cossart, Monique Fort, Aline Garnier, Frédéric Gob, Franck Lavigne, Charles Le Cœur, Romain Perrier, Nathalie Thommeret). The organization of the meeting benefited from the financial support of the PRODIG (UMR CNRS 8586) and LGP (UMR CNRS 8591) laboratories, as well as the logistical support of the UFR of Geography of the Panthéon-Sorbonne University (Paris 1). We would also like to thank Nathalie Carcaud for her picture of the Val de Loire, which allowed us to complete the illustration, as well as Monique Fort, who accepted to read the first version of this editorial. Last we thank all the 14 reviewers who evaluated the manuscripts of this special issue, as well as the successive editors-in-chief of the journal, Gilles Arnaud-Fassetta and Pierre-Gil Salvador, who greatly helped us in the ultimate formatting of the manuscripts.
1The 14th Young Geomorphologists Meeting (JJG 2013), the annual symposium sponsored by the Groupe Français de Géomorphologie, took place on the 11th and 12th of January 2013. This meeting was organized by both the Panthéon-Sorbonne University (Paris 1) and Paris-Diderot University (Paris 7), along with the PRODIG (UMR-CNRS 8586) and LGP (UMR-CNRS 8591) laboratories. Four thematic sessions structured this scientific event: Session 1: “Indicators of landform dynamics”, Session 2: “Recorders of environmental evolutions”, Session 3: “Modeling and quantification of changes”, Session 4: “Stream hydrogeomorphology”. Together with 21 oral presentations, scientific posters were also on display. Grouped around the theme of “Geomorphology from the bachelor’s degree to the Ph.D.” and co-organized by BA, MA and Ph.D. students from the universities of Paris 1, Paris 4, Paris 7 and UPEC, this poster session took place in the hall of the Institute of Geography, where the event was held. Between two thematic sessions, the projection of the film “Trainee researchers” directed by Marie Chenet took place late on Saturday morning the 12th. The film stressed the importance of fieldwork in geomorphological studies at university. Finally, these two days of meeting brought together nearly sixty researchers from twenty different institutions.
2The Young Geomorphologists Meeting provides an excellent image of current trends and research orientation in geomorphology. In addition to a very important and active community of young researchers working on river dynamics at various scales and in diverse environments (mountainous, plains, urban, peri-urban, etc.), numerous presentations focused on slope dynamics, leading to hazards and risks for societies. On this last theme, it has been shown that analyses can rely on a set of diversified indicators and methods of investigation to better apprehend mass movements at various scales (morphometric, dendro-geomorphological, modeling approach, etc.). Finally, the use of diverse geomorphological markers to reconstruct present-day or past environmental and climatic changes remains strong within the research conducted by young scholars in geomorphology, which includes numerous applications, mainly in the field of resource and risk management. These scientific communications show the highly applicable nature of current research in geomorphology. The question of how applicable this research is, generally starting as a fundamental one, lies at the center of leading-edge geomorphological research now conducted by a new generation of scholars. Such research addresses the need for increasing expertise in decision-making support, mainly in the field of so-called “natural” risk evaluation and management (Alexander, 1991; Oya, 2001; Allison, 2002; Battiau-Queney, 2002; Mercier et al., 2013) (fig. 1). Moreover, it is in this subject that many of them will find (or have already found) a job.
Fig. 1 – Géomorphologie applicable : illustration de quatre processus géomorphologiques dont la prise en compte est pertinente pour la gestion des milieux et des risques.
Fig. 1 – Applicable geomorphology: illustration of four geomorphic processes relevant to environmental and risk management.
A : inondation de l'Île de Chalonnes s/Loire, janvier 2004 ; B : dégradation des terres et érosion des sols de type ravinement : formation de voçorocas sur un versant déboisé du Massif de Pereiro (Ceará, Brésil) ; C : mouvements de terrain complexes et de grande ampleur : les « Ruines de Séchilienne » (Isère, France), un site à risques naturels et technologiques hautement surveillé ; D : érosion côtière sur une plage du Finistère (Bretagne Sud, Ile Tudy), après les tempêtes de janvier 2014.
A: flooding of the Chalonnes s/ Loire island, January 2014; B: land degradation and gully erosion: formation of voçorocas on a deforested hillslope of the Pereiro Massif (Ceará, Brazil); C: complex and large-scale mass movements: the “Ruines de Séchilienne” (Isère, France), a site prone to natural and technological risks equipped with a monitoring network; D: coastal erosion on a beach of Finistère (South Brittany, France, Ile Tudy), after the storms of January 2014.
A : cliché N. Carcaud ; B et C : cliché F. Bétard ; D : cliché Y. Le Drézen.
A: photo N. Carcaud; B et C: photos F. Bétard; D: photo Y. Le Drézen.
3Among the geomorphic processes considered today when mapping hazard and risk prevention in France, hillslope movements and processes of mass wasting represent an important part. The paper written by N. Bollot et al. (this volume) was initially based on fundamental research dealing with the characterization of mass movements in Eocene strata from the eastern Paris Basin (plateau of the Tardenois and the Soissonnais). His study reveals an original phenomenon of valley cambering, considered as a complex mass movement. In reality this is an ancient process, leading to the formation of stable slopes, differing in that sense from recurrent landslides on other slopes observed in the same region. This kind of study, which allows for the evaluation of slope stability, thus contributes indirectly to the preparation of hazard maps. Moreover, as another valorization of their work, the authors estimate that the cambered slopes of the Soissonnais and the Tardenois deserve to be recognized as a geomorphosite, because of their remarkable character and their exemplary nature.
4In the Alps, landslides are amongst the most frequent geomorphic processes and are responsible for considerable socio-economic damage. Determining the predisposing and triggering factors of these events and mapping them are major stakes for both scientists and managers. Based on a dendro-geomorphological approach, the paper written by J. Lopez-Saez et al. (this volume) highlights how exposed tree root surfaces can provide a reliable indicator of local landlisdes. Results contribute in particular to establishing a precise chronology of the temporal occurrence and spatial distribution of hazards, which is a necessary prerequisite for risk evaluation and management.
5Perfectly integrated in the area of expertise of geomorphologists, anticipating landslide hazards remains a key objective in risk management and requires the creation of well-adapted monitoring networks, as part of the establishment of early-warning systems. Choosing techniques and setting the surveillance network depends on the type of mass movement studied and the precision searched for. The paper written by C. Lissak et al. (this volume) highlights how, using the case of a landslide in Basse-Normandie, field equipment allows one not only to understand the behaviour and kinematics of a slow mass movement, but also to define critical triggering thresholds based on continuously measured piezometric levels. This type of study is all the more necessary as the landslide above-mentioned is located in a coastal area where important economic and human issues prevail, and as it can contribute in an effective way to the installation of an integrated monitoring system for a better protection of goods and people.
6In the framework of the national strategy for the integrated management of coastal lines, following the commitments of the 2009 Grenelle of the Sea, the French State and territorial authorities recently pledged to better take into account coastal erosion in public policies by sharing knowledge and local strategies. Because of the increasing vulnerability of coastal areas faced with global changes (e.g. global rise in sea level), the knowledge and management of coastal erosion risks are particularly relevant at the present juncture and are a prime concern for geomorphologists. This recent awareness strengthens the need for coastal line observation, risk area identification, and definition of pertinent indicators to measure erosion speed. The paper of P. Letortu et al. (this volume) corresponds precisely to this kind of approach and applicable research. Based on the quantification of the rates of limestone cliff retreat in Haute-Normandie, the results obtained from the fundamental research undertaken have direct societal implications. Indeed, on the one hand, they provide a map of recession rates and their explanation, and on the other hand allow one to estimate the rhythm with which the cliffs evolve. This dual approach explores possible answers for the relocation of goods and people unwisely settled too close to the edge of cliffs.
7For the last 10 years, the evolution of the regulatory framework and legislation concerning rivers, both in France and in Europe, has favoured the emergence of numerous studies on applicable fluvial geomorphology, even if this kind of research started to develop at least three decades ago (Hook, 1986; Gregory et al., 2008). In France, the hydrogeomorphological approach is today the recommended method for flood risk mapping (Masson et al., 1996). At European level, the drafting of the Water Framework Directive (DCE) in 2000 introduced the notion of fluvial “hydrogeomorphology” in the legislation together with the principles of ecological and sediment continuity of rivers. This regulatory text, superimposed upon the 2006 law on water and aquatic environments (LEMA) in France has highlighted the importance of quantifying and characterizing sediment transfers for river management and restoration. Indeed, the consequences of these transfers can be disastrous, not only for ecosystems and biodiversity, but also for populations (floods, pollution). In order to better understand the modes of water and sediment transfer from the areas of production (cultivated areas) to the outlet of the watershed, the paper written by V. Viel et al. (this volume) puts forward an approach to map areas potentially connected to the water system in the Lower Normandy hedged farmlands. This method goes beyond defining a simple level of soil static sensitivity to erosion and is a first step toward evaluating the influence of hillside slopes on sediment fluxes in rivers. Such research contributes to making hydrogeomorphology a useful field of research to help develop monitoring and restoration guidelines for rivers.
8Referring to the words of J. Tricard in his “Applicable Geomorphology” published in 1978: “opposing fundamental and application research makes no sense”: one can’t choose between producing fundamental knowledge and participating in solving practical issues faced by societies. The research produced by young researchers, a reflection of current research in this discipline, shows that geomorphology is resolutely useful. Such an applicable geomorphology is more specifically centered on the study of geomorphic processes which have an impact on society, mainly concerning the management of hazards and risks such as floods, soil erosion, mass movements or coastal erosion (fig. 1). The evolution of geomorphological research in this direction, strongly linked to environmental management and land-use planning, offers a wide range of future perspectives in this subject, in a professional world more and more connected with universities.
Table des illustrations
|Titre||Fig. 1 – Géomorphologie applicable : illustration de quatre processus géomorphologiques dont la prise en compte est pertinente pour la gestion des milieux et des risques. Fig. 1 – Applicable geomorphology: illustration of four geomorphic processes relevant to environmental and risk management.|
|Légende||A : inondation de l'Île de Chalonnes s/Loire, janvier 2004 ; B : dégradation des terres et érosion des sols de type ravinement : formation de voçorocas sur un versant déboisé du Massif de Pereiro (Ceará, Brésil) ; C : mouvements de terrain complexes et de grande ampleur : les « Ruines de Séchilienne » (Isère, France), un site à risques naturels et technologiques hautement surveillé ; D : érosion côtière sur une plage du Finistère (Bretagne Sud, Ile Tudy), après les tempêtes de janvier 2014.A: flooding of the Chalonnes s/ Loire island, January 2014; B: land degradation and gully erosion: formation of voçorocas on a deforested hillslope of the Pereiro Massif (Ceará, Brazil); C: complex and large-scale mass movements: the “Ruines de Séchilienne” (Isère, France), a site prone to natural and technological risks equipped with a monitoring network; D: coastal erosion on a beach of Finistère (South Brittany, France, Ile Tudy), after the storms of January 2014.|
Pour citer cet article
François Bétard, Yann Le Drézen et Louise Purdue, « Introduction to the thematic issue “Applicable geomorphology: from natural processes to environmental and risk management” (proceedings of the 14th Young Geomorphologists Meeting) », Géomorphologie : relief, processus, environnement, vol. 20 - n° 2 | 2014, 115-120.
François Bétard, Yann Le Drézen et Louise Purdue, « Introduction to the thematic issue “Applicable geomorphology: from natural processes to environmental and risk management” (proceedings of the 14th Young Geomorphologists Meeting) », Géomorphologie : relief, processus, environnement [En ligne], vol. 20 - n° 2 | 2014, mis en ligne le 29 septembre 2014, consulté le 24 avril 2017. URL : http://geomorphologie.revues.org/10572Haut de page
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