Hervé Piégay
Biographic Data
| ID | 1340511 |
|---|---|
| NAME | Hervé Piégay |
| GIVEN NAMES | Hervé |
| FAMILY NAME | Piégay |
| SIGNATURE | PIÉGAY H |
| AFFILIATIONS | Lyon 1 Université |
| ORCID | 0000-0002-3864-2119 |
| VERIFIED | Yes |
| TOTAL WORKS | 22 |
| TOTAL CITATIONS | 21 |
| AUTHOR COUNT | 22 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1995 |
| LATEST PUBLICATION YEAR | 2024 |
| H-INDEX | 2 |
Publications reveal how socio-ecological research is implemented
Effects of repeated drawdown flushing on riverbed fine sediment dynamics downstream from a dam
Deep learning ancient map segmentation to assess historical landscape changes
Ancient geographical maps are our window into the past for understanding the spatial dynamics of last centuries. This paper proposes a novel approach to address this problem using deep learning. Convolutional neural networks (CNNs) are today the state-of-the-art methods in handling a variety of problems in the fields of image processing. The Cassini map, created in the eighteenth century, is used to illustrate our methodology. This approach enabl…
Automatic vectorization of fluvial corridor features on historical maps to assess riverscape changes
The vectorization of historical maps is an important scientific issue for understanding the dynamics of change recorded by territories. Historical maps are potentially an excellent source of data for characterizing river changes at large scales. The use of vectorized data is essential for such characterization, as well as for highlighting changes in the planform alignment of such reaches over time. At a regional network scale of several thousand …
Environmental Flows
Environmental flows (or e‐flows) are measures implemented to mitigate the downstream environmental impacts of dams. Improvements may involve flow magnitude (e.g., minimum or high flows), duration, frequency, or seasonal regime. Different terms are used to characterize such flow improvements, also called water releases, according to their objectives. The aim is to modify the hydrological regime itself, or the hydraulic or geomorphic conditions, to…
To dam or not to dam in an age of anthropocene
International audience
Assessing Historical Maps for Characterizing Fluvial Corridor Changes at a Regional Network Scale
Fluvial corridor quality assessment requires that historical data be collected at a regional scale. In this article, our goal is to assess potential map resources to explore riverscape changes at a regional network scale and to define key issues in using an automated vectorization protocol to characterize such changes on such a large scale. We consider IGN’s Nouvelle Carte de France a potentially good resource for our objective of two-date (oldes…
Legacy sediments in a European context
Quantitative Geomorphology
Quantitative geomorphology developed as a school of thought during the 1950s and 1960s. Pioneer researchers introduced process‐based thinking supported by measurements to explain land form evolution and characteristics. Quantitative geomorphology was founded on the idea that objectivity and observations should be reinforced by quantification using instruments that provide reliable and precise data. It contrasts with qualitative (visual) observati…
Power and Changing Riverscapes
Riverscapes are constructs that mix natural components with political, socioeconomic, and technical strategies. This article shows how the riverscapes of the Rhône in France have changed under the influence of different power relations. We use newspapers to highlight the potential of news outlets as a data source with which to apply Foucault’s critical and genealogical methods and to develop a political ecology of socioecological fixes. Media cov…
Quantitative Geomorphology
Quantitative geomorphology developed as a school of thought during two main periods: the 1950–1960s and the 2000s. During the first period, pioneer researchers introduced process‐based thinking supported by measurements to explain land form evolution and characteristics. Quantitative geomorphology was founded on the idea that objectivity should be reinforced by quantification using instruments that provide reliable and precise data. It contrasts …
Regional Scale Mapping of Debris-Flow Susceptibility in the Southern French Alps
This article describes a regional methodology of debris-flow susceptibility mapping. The implementation of this approach is based on statistical and GIS methods and makes it possible to identify catchments in the Southern French Alps, according to their morphometric (Melton index and local slope) and sediment supply conditions (active erosion zones in headwater catchments), that are prone to debris flows because of hydrometeorological forcing. Th…
Cartographie régionale de la susceptibilité aux laves torrentielles dans les Alpes du Sud
Cet article décrit une méthodologie régionale d’identification des torrents susceptibles d’initier et de propager des laves torrentielles. La mise en œuvre de cette démarche d’évaluation, mobilisant des méthodes statistiques et géomatiques a permis de distinguer sur le territoire des Alpes du Sud les bassins versants inférieurs à 40 km2 en fonction de leur aptitude à former des laves torrentielles sous l’effet des forçages hydrométéorologiques, s…
Les Agences de l’eau et la restauration
Le paradigme de la restauration occupe une place importante au sein de la gestion actuelle de l’eau et des milieux aquatiques. Depuis son apparition dans les sphères scientifiques et opérationnelles à la fin des années 1970, le paradigme s’est complexifié et les significations associées aux différents concepts de restauration, renaturation et réhabilitation ont également évolué sans que les définitions et les pratiques auxquelles ils renvoient so…
Diversité des savoirs relatifs aux milieux aquatiques
L’articulation des savoirs locaux et scientifiques est l’un des principaux enjeux de la gestion concertée des milieux aquatiques. Les projets de restauration écologique interrogent plus particulièrement les savoirs relatifs aux évolutions environnementales. Ces derniers contribuent en effet à fixer les références environnementales et/ou les objectifs à atteindre. L’hétérogénéité des savoirs propres aux différentes catégories d’acteurs d’un projet…
Les restaurations de rivières sur Internet
En érigeant le « bon état écologique » des rivières en objectif à atteindre, la directive-cadre européenne sur l’eau oblige à questionner les pratiques actuelles et passées dans le domaine de la restauration. Un premier recensement national a été réalisé via Internet et a permis d’identifier 480 actions déclarées comme relevant du domaine de la restauration de rivières. Les résultats conduisent à formuler plusieurs constats : 1. Le terme de resta…
Variations in cross‐cultural perception of riverscapes in relation to in‐channel wood
Human perception of riverscapes with and without large wood (LW) has been investigated with a photo‐questionnaire submitted to 2250 students in ten countries, capturing reactions to 20 pictures in terms of naturalness, danger, aesthetics and need for improvement. Principal component analysis performed on average scores per country per item showed that the primary discriminating factors are human modification, turbulence and extent of water shown …
Les photographies prises au sol
Pour intégrer le paysage dans la gestion globale des cours d'eau, nous proposons une méthode permettant d'établir un diagnostic paysager, basée sur une analyse qualitative et quantitative de la structure éco-géographique du paysage et une analyse de sa perception par les différents acteurs. Ces analyses complémentaires, réalisées à des fins de gestion, permettent au gestionnaire de connaître les différentes facettes micro paysagères de son cours …
Reflections on the Notions of "Empire" and "Kingdom" in Seventeenth-Century Ethiopia
The purpose of this article is to re-interrogate the notions of "empire" and "kingdom" in seventeenth-century Ethiopia, attentive to the borrowings and models used by the sources, which are particularly rich for this period. But it is equally through a study of a person close to King Susneyos, the the ras Se'lä Krestos, and the relations that he maintained with his sovereign, that we can reformulate these notions of "empire" and "kingdom
Questions of water resources management. Feedback on the implementation of the French Sage and SDAGE plans (1992–2001)
Principes nouveaux en matière de gestion des marges de rivières en tresses (exemple de la moyenne vallée du Giffre, Haute-Savoie, France) / New principles relating to the management of braided streamw…
The importance of the streamway preservation concept is increasingly recognised by the managers of high-energy hydrosystems. The paper examines the eco-geographical, patrimonial and economic reasons for this new approach through a case study of the middle Giffre valley (Haute Savoie, France). Lateral instability of the channel is evaluated using a geomorphological analysis based on a GIS raster, the result providing useful input in the decision-m…
L'intégration des stratégies foncières individuelles dans la gestion des lits majeurs boisés (Exemple de quatre rivières de rang intermédiaire du bassin du Rhône) / Integrating individual land managem…
Integrating individual land management strategies into the overall management of forested flood plains : the example of four intermediate-level rivers in the Rhone basin. Prior to 1992, river management tended to be sector- based, but the Water Act of that year confirmed the importance of the global approach, essential for the sound management and protection of aquatic ecosystems. River management can no longer be restricted to the linear extent …
Power and Changing Riverscapes
Riverscapes are constructs that mix natural components with political, socioeconomic, and technical strategies. This article shows how the riverscapes of the Rhône in France have changed under the influence of different power relations. We use newspapers to highlight the potential of news outlets as a data source with which to apply Foucault’s critical and genealogical methods and to develop a political ecology of socioecological fixes. Media cov…
To dam or not to dam in an age of anthropocene
International audience
Variations in cross‐cultural perception of riverscapes in relation to in‐channel wood
Human perception of riverscapes with and without large wood (LW) has been investigated with a photo‐questionnaire submitted to 2250 students in ten countries, capturing reactions to 20 pictures in terms of naturalness, danger, aesthetics and need for improvement. Principal component analysis performed on average scores per country per item showed that the primary discriminating factors are human modification, turbulence and extent of water shown …
Reflections on the Notions of "Empire" and "Kingdom" in Seventeenth-Century Ethiopia
The purpose of this article is to re-interrogate the notions of "empire" and "kingdom" in seventeenth-century Ethiopia, attentive to the borrowings and models used by the sources, which are particularly rich for this period. But it is equally through a study of a person close to King Susneyos, the the ras Se'lä Krestos, and the relations that he maintained with his sovereign, that we can reformulate these notions of "empire" and "kingdom
L'intégration des stratégies foncières individuelles dans la gestion des lits majeurs boisés (Exemple de quatre rivières de rang intermédiaire du bassin du Rhône) / Integrating individual land managem…
Integrating individual land management strategies into the overall management of forested flood plains : the example of four intermediate-level rivers in the Rhone basin. Prior to 1992, river management tended to be sector- based, but the Water Act of that year confirmed the importance of the global approach, essential for the sound management and protection of aquatic ecosystems. River management can no longer be restricted to the linear extent …
Principes nouveaux en matière de gestion des marges de rivières en tresses (exemple de la moyenne vallée du Giffre, Haute-Savoie, France) / New principles relating to the management of braided streamw…
The importance of the streamway preservation concept is increasingly recognised by the managers of high-energy hydrosystems. The paper examines the eco-geographical, patrimonial and economic reasons for this new approach through a case study of the middle Giffre valley (Haute Savoie, France). Lateral instability of the channel is evaluated using a geomorphological analysis based on a GIS raster, the result providing useful input in the decision-m…
Questions of water resources management. Feedback on the implementation of the French Sage and SDAGE plans (1992–2001)
Reflections on the Notions of "Empire" and "Kingdom" in Seventeenth-Century Ethiopia
The purpose of this article is to re-interrogate the notions of "empire" and "kingdom" in seventeenth-century Ethiopia, attentive to the borrowings and models used by the sources, which are particularly rich for this period. But it is equally through a study of a person close to King Susneyos, the the ras Se'lä Krestos, and the relations that he maintained with his sovereign, that we can reformulate these notions of "empire" and "kingdom
Les photographies prises au sol
Pour intégrer le paysage dans la gestion globale des cours d'eau, nous proposons une méthode permettant d'établir un diagnostic paysager, basée sur une analyse qualitative et quantitative de la structure éco-géographique du paysage et une analyse de sa perception par les différents acteurs. Ces analyses complémentaires, réalisées à des fins de gestion, permettent au gestionnaire de connaître les différentes facettes micro paysagères de son cours …
Variations in cross‐cultural perception of riverscapes in relation to in‐channel wood
Human perception of riverscapes with and without large wood (LW) has been investigated with a photo‐questionnaire submitted to 2250 students in ten countries, capturing reactions to 20 pictures in terms of naturalness, danger, aesthetics and need for improvement. Principal component analysis performed on average scores per country per item showed that the primary discriminating factors are human modification, turbulence and extent of water shown …
Les restaurations de rivières sur Internet
En érigeant le « bon état écologique » des rivières en objectif à atteindre, la directive-cadre européenne sur l’eau oblige à questionner les pratiques actuelles et passées dans le domaine de la restauration. Un premier recensement national a été réalisé via Internet et a permis d’identifier 480 actions déclarées comme relevant du domaine de la restauration de rivières. Les résultats conduisent à formuler plusieurs constats : 1. Le terme de resta…
Diversité des savoirs relatifs aux milieux aquatiques
L’articulation des savoirs locaux et scientifiques est l’un des principaux enjeux de la gestion concertée des milieux aquatiques. Les projets de restauration écologique interrogent plus particulièrement les savoirs relatifs aux évolutions environnementales. Ces derniers contribuent en effet à fixer les références environnementales et/ou les objectifs à atteindre. L’hétérogénéité des savoirs propres aux différentes catégories d’acteurs d’un projet…
Les Agences de l’eau et la restauration
Le paradigme de la restauration occupe une place importante au sein de la gestion actuelle de l’eau et des milieux aquatiques. Depuis son apparition dans les sphères scientifiques et opérationnelles à la fin des années 1970, le paradigme s’est complexifié et les significations associées aux différents concepts de restauration, renaturation et réhabilitation ont également évolué sans que les définitions et les pratiques auxquelles ils renvoient so…
Quantitative Geomorphology
Quantitative geomorphology developed as a school of thought during two main periods: the 1950–1960s and the 2000s. During the first period, pioneer researchers introduced process‐based thinking supported by measurements to explain land form evolution and characteristics. Quantitative geomorphology was founded on the idea that objectivity should be reinforced by quantification using instruments that provide reliable and precise data. It contrasts …
Regional Scale Mapping of Debris-Flow Susceptibility in the Southern French Alps
This article describes a regional methodology of debris-flow susceptibility mapping. The implementation of this approach is based on statistical and GIS methods and makes it possible to identify catchments in the Southern French Alps, according to their morphometric (Melton index and local slope) and sediment supply conditions (active erosion zones in headwater catchments), that are prone to debris flows because of hydrometeorological forcing. Th…
Cartographie régionale de la susceptibilité aux laves torrentielles dans les Alpes du Sud
Cet article décrit une méthodologie régionale d’identification des torrents susceptibles d’initier et de propager des laves torrentielles. La mise en œuvre de cette démarche d’évaluation, mobilisant des méthodes statistiques et géomatiques a permis de distinguer sur le territoire des Alpes du Sud les bassins versants inférieurs à 40 km2 en fonction de leur aptitude à former des laves torrentielles sous l’effet des forçages hydrométéorologiques, s…
Quantitative Geomorphology
Quantitative geomorphology developed as a school of thought during the 1950s and 1960s. Pioneer researchers introduced process‐based thinking supported by measurements to explain land form evolution and characteristics. Quantitative geomorphology was founded on the idea that objectivity and observations should be reinforced by quantification using instruments that provide reliable and precise data. It contrasts with qualitative (visual) observati…
Power and Changing Riverscapes
Riverscapes are constructs that mix natural components with political, socioeconomic, and technical strategies. This article shows how the riverscapes of the Rhône in France have changed under the influence of different power relations. We use newspapers to highlight the potential of news outlets as a data source with which to apply Foucault’s critical and genealogical methods and to develop a political ecology of socioecological fixes. Media cov…
Assessing Historical Maps for Characterizing Fluvial Corridor Changes at a Regional Network Scale
Fluvial corridor quality assessment requires that historical data be collected at a regional scale. In this article, our goal is to assess potential map resources to explore riverscape changes at a regional network scale and to define key issues in using an automated vectorization protocol to characterize such changes on such a large scale. We consider IGN’s Nouvelle Carte de France a potentially good resource for our objective of two-date (oldes…
Legacy sediments in a European context
Environmental Flows
Environmental flows (or e‐flows) are measures implemented to mitigate the downstream environmental impacts of dams. Improvements may involve flow magnitude (e.g., minimum or high flows), duration, frequency, or seasonal regime. Different terms are used to characterize such flow improvements, also called water releases, according to their objectives. The aim is to modify the hydrological regime itself, or the hydraulic or geomorphic conditions, to…
To dam or not to dam in an age of anthropocene
International audience
Automatic vectorization of fluvial corridor features on historical maps to assess riverscape changes
The vectorization of historical maps is an important scientific issue for understanding the dynamics of change recorded by territories. Historical maps are potentially an excellent source of data for characterizing river changes at large scales. The use of vectorized data is essential for such characterization, as well as for highlighting changes in the planform alignment of such reaches over time. At a regional network scale of several thousand …
Deep learning ancient map segmentation to assess historical landscape changes
Ancient geographical maps are our window into the past for understanding the spatial dynamics of last centuries. This paper proposes a novel approach to address this problem using deep learning. Convolutional neural networks (CNNs) are today the state-of-the-art methods in handling a variety of problems in the fields of image processing. The Cassini map, created in the eighteenth century, is used to illustrate our methodology. This approach enabl…
Publications reveal how socio-ecological research is implemented
Effects of repeated drawdown flushing on riverbed fine sediment dynamics downstream from a dam
Geography (14 works) · Cartography (9 works) · Political science (9 works) · Hydrology and Sediment Transport Processes (8 works) · Soil erosion and sediment transport (8 works) · Geomorphology (7 works) · Computer Science (6 works) · Environmental Science (6 works) · Geology (6 works) · Philosophy (6 works)