Laurent Lespez

Université Paris-Est Créteil Val de Marne - Université Paris 12 | UPEC · Département de Géographie & Laboratoire de Géographie Physique CNRS

This article assesses the long-term hydro-sedimentary and ecological consequences of the urban pressure around Paris over the last 3000 years on the M erantaise river. Using a geoarchaeological approach combining sedimentological, geochemical, palynological and geophysical investigations enabled us to identify the transformations of the hydrosystem...

Shifting cultivation is widely practiced in many tropical mountainous watersheds. Agricultural practices are changing with the intensification of activities and the development of industrial monocultures associated with increasing land use and the use of pesticides and fertilisers. These changes have consequences for the evolution of sediment trans...

The Ravin Blanc I archaeological occurrence, dated to MIS 5, provides unprecedented data on the Middle Stone Age (MSA) of West Africa since well-contextualized archaeological sites pre-dating MIS 4/3 are extremely rare for this region. The combined approach on geomorphology, phytolith analysis, and OSL date estimations offers a solid framework for...

Morphological adjustment mechanisms and controls of small urban rivers are rarely studied especially in France. We propose an original hydrogeomorphological approach based on a detailed study of a whole catchment using field data acquired systematically all along the river: (i) channel cross‐sections; (ii) riffle‐pool sequences and (iii) obstacles...

A geomorphological survey immediately west of the Minoan town of Malia (Crete) shows that a tsunami resulting from the Bronze Age Santorini eruption reached the outskirts of the Palatial center. Sediment cores testify a unique erosional event during the Late Minoan period, followed locally by a high energy sand unit comprising marine fauna. This co...

La mission archéologique menée en 2021 dans le cadre du projet « Peuplement humain et paléoenvironnement en Afrique – Projet Falémé » a eu lieu entre le 7 décembre 2020 et le 10 avril 2021 au Sénégal oriental, dans la vallée de la Falémé, après une phase de préparation administrative et logistique à Bamako au Mali. Elle s’est terminée à Dakar par d...

Après avoir été au cœur de la géographie française durant toute la première moitié du XXe siècle, la géomorphologie s'est profondément renouvelée en même temps que la discipline géographique, entre les années 1970 et 1990, avec l’apparition d’une géomorphologie dynamique et quantitative de plus en plus appliquée. Cette tendance s’est affirmée et re...

Over the past decade, the increasing wealth of new archaeological data on the Middle Stone Age (MSA) in Senegal and Mali has broadened our understanding of West Africa's contributions to cultural developments. Within the West African sequence, the phase of Marine Isotope Stage 3 (MIS 3, ca. 59-24 ka) yielded so far the best known and extensive arch...

This research operates in the field of the paleogeographic reconstruction, whose purpose is the study of the changes registered by the structure and functioning of natural systems over time. What did these modifications consist of, why and when did they occur and what consequences did they have on landscape settings? Concerning the last millennia o...

Suburban streams often considered as our least restorable ecosystems but in fact constitute an important part of the hydrographic network in megalopolis and crucial environmental infrastructures for future urban development. Numerous studies have highlighted the dramatic hydrogeomorphological and ecological alterations due to the hydrological conse...

Hommage collectif.

Dans le cadre du programme de recherche sur le mégalithisme sénégambien (Dir. H. Bocoum et L. Laporte), des recherches visent à documenter le cadre environnemental précis dans lequel se sont développées les civilisations contemporaines. Pour cela, il faut faire appel à des données obtenues dans les archives sédimentaires continentales qui permetten...

La mission de terrain 2020 dans la Vallée de la Falémé, Sénégal oriental, avait pour objectif de documenter plus précisément les dynamiques d’occupation les plus anciennes, de l’Acheuléen au Middle Stone Age ; de mettre en évidence le passage, encore mal compris, des derniers chasseurs-cueilleurs aux sociétés productrices ; de préciser la variabili...

Dam removal represents one of the most emblematic operations of the ecological restoration of rivers. Developed in the United States of America in the 1990s, dam removal has become a major practice to achieve the “good ecological status” of water bodies required by the European Union (EU) Water Framework Directive (WFD) in France. However, ecologic...

Conflicts over dam removal have attracted substantial scholarly attention over the past years, although this research has generally focused on evaluating local-scale conflicts. Far less is known about the role of institutional frameworks in shaping conflicts at regional and national scales. We complement and extend this discussion by highlighting t...

Published table 1, in table format for more clarity. From: Douze et al. 2021. A West African Middle Stone Age site dated to the beginning of MIS 5: Archaeology, chronology, and paleoenvironment of the Ravin Blanc I (eastern Senegal). Journal of Human Evolution, 154, 102952.

The hybrids, the geography of nature and environment In the Anthropocene era, the transformation of material nature by societies is increasingly being assimilated. To describe this new situation, following the work of M. Serres and B. Latour, many studies suggest considering the contemporary nature as the result of hybridation of nature and culture...

The end of the Palaeolithic represents one of the least-known periods in the history of western Africa, both in terms of its chronology and the identification of cultural assemblages entities based on the typo-technical analyses of its industries. In this context, the site of Fatandi V offers new data to discuss the cultural pattern during the Late...

Dans la Plaine de Caen, les études paléoenvironnementales interdisciplinaires montrent un problème de divergence de représentativité spatiale et temporelle dans la corrélation des données hors-sites et intrasites du Néolithique. Pour appréhender finement les interactions entre changements environnementaux et développement des pratiques agricoles, d...

The site of Malia, on the northwest coast of Crete is stimulating for geoarchaeological research. A Minoan palatial town developed during the Middle and Late Bronze Ages in an area that was occupied for a long time, and has been the subject of archaeological excavations for a century. A small wetland located near the sea and close to the archaeolog...

Les études menées le long de la Falémé, affluent du Sénégal, dans le secteur Sansandé-Missira, permettent de se faire une idée assez précise de la stratigraphie des formations sédimentaires qui se dévoilent à la faveur de l'incision récente du cours d'eau. Les datations par le radiocarbone et par luminescence optiquement stimulée calent l'essentiel...

Les études menées le long de la Falémé, affluent du Sénégal, dans le secteur Sansandé-Missira, permettent de se faire une idée assez précise de la stratigraphie des formations sédimentaires qui se dévoilent à la faveur de l’incision récente du cours d’eau. Les datations OSL calent l’essentiel de ces dépôts du dernier cycle climatique, avec une très...

La vallée de la Falémé (Sénégal Oriental) fait l'objet de recherches paléoenvironnementales et archéologiques depuis 2012. Le potentiel des archives sédimentaires concernant l'étude des trois derniers millénaires est maintnenat avéré, particulièrement dans les ravins latéraux de la vallée principale. Le style méandriforme de la Falémé offre de larg...

Dans le cadre du projet Peuplement humain et paléoenvironnement en Afrique, coordonné par l’un des auteurs (É.H.) et financé par le Fonds National Suisse de la recherche scientifique (FNS), la Fondation Suisse-Liechtenstein pour les Recherches Archéologiques à l’Étranger (SLSA), l’Agence Nationale de la Recherche française (ANR) et la Faculté des S...

Sixty modern surface samples collected from mosses in different cypress forest communities (Cupressus sempervirens L.) on the island of Crete (Greece) were analysed for their pollen content. The samples were taken from six different cypress phytosociological associations between 23 and 1600 m asl, and fall within distinct rainfall and temperature r...

Trying to model a rural society, and even more so a past and disappeared rural society, is a dangerous task in the sense that we deal with the complexity of a whole society whatever the purpose of the model, to integrate and/or to simplify in a proper manner. This article deals with this complexity mainly by exploring the least risky way to apprehe...

Through the example of a project for the removal of two hydroelectric dams of 16 and 36 metres in height spanning the Sélune River, this article examines the importance of the landscape in such a project and in the discussions concerning its implementation. The removal of obstacles spanning a river leads to a major reconfiguration of river environm...

Through the example of a project for the removal of two hydroelectric dams of 16 and 36 metres in height spanning the Sélune River, this article examines the importance of the landscape in such a project and in the discussions concerning its implementation. The removal of obstacles spanning a river leads to a major reconfiguration of river environm...

Landscape evolution from the Early 1st millennium BCE to the mid-1st millennium CE is poorly documented around major archaeological sites in Crete. In a previous publication, the general landscape configuration in the vicinity of ancient Phaistos was reconstructed using a palaeoenvironmental approach, from the Proto-Palatial period (ca. 2000BCE) to...

Many societal and environmental changes occurred between the 2nd millennium BC and the middle of the 2nd millennium AD in western Africa. Key amongst these were changes in land use due to the spread and development of agricultural strategies, which may have had widespread consequences for the climate, hydrology, biodiversity, and ecosystem services...

As part of the Changing the Face of the Mediterranean Project, we consider how human pressure and concomitant erosion has affected a range of Mediterranean landscapes between the Neolithic and, in some cases, the post-medieval period. Part of this assessment comprises an investigation of relationships among palaeodemographic data, evidence for vege...

In West Africa, most palaeoenvironmental studies have focused on the role of climatic change on the environment. Because of the richness of its deposits, the Yamé River (Mali), a tributary of the Niger River, offers an opportunity to reconstruct the evolution of this fluvial system in comparison with both climatic and anthropogenic changes during t...

The Sangsurière marsh is located in the regional nature park of the Cotentin and Bessin marshes. The park was created in 1991 mainly because of the large biodiversity existing in its wet areas. The aim of our research is to study : 1/ the history of the wet areas formation ; 2/ the respective role of natural and anthropogenic factors in the formati...

Many societal and environmental changes occurred from the 2nd millennium BC to the middle of the 2nd millennium AD in western Africa. Key amongst these were changes in land use due to the spread and development of agricultural strategies, which may have had widespread consequences for the climate, hydrology, biodiversity, and ecosystem services of...

As part of the Changing the Face of the Mediterranean Project, we consider how human pressure and concomitant erosion has affected a range of Mediterranean landscapes between the Neolithic and, in some cases, the post-medieval period. Part of this assessment comprises an investigation of relationships among palaeodemographic data, evidence for vege...

L'âge du Bronze, entre 2300 et 800 avant notre ère, est une période charnière qui nous permet de rentrer de plain-pied dans l'histoire. À cette époque, des bateaux chargés de marchandises voguent sur la Manche, participant à une florissante économie transmanche avec l'Angleterre. Le territoire national, et plus particulièrement la Normandie, est un...

The aim of this paper is to present the preliminary results of the study of a Recent Holocene sedimentary sequence located in the Falémé valley in Eastern Senegal (West Africa). Geomorphological prospections and archeological excavations are performed in this area since 2011. So far the research allowed an understanding of the valley geometry and t...

The paucity of modern pollen rain data from the Aegean islands is a significant barrier to understand the late Quaternary vegetation history of this globally important south-eastern Mediterranean region. This paper presents the study of 30 modern pollen and non-pollen palynomorph assemblages carried out along an altitudinal gradient from 0 to 2453...

Les recherches géomorphologiques et paléoenvironnementales développées le long de la Falémé mettent en évidence une sédimentation alluviale et colluviale très développée pour les trois derniers millénaires. L’importance de cette sédimentation a permis d’amorcer une étude des dynamiques paysagères et environnementales sur une échelle de temps encore...

Bifacial points are widespread tools over the northern half of the African continent during the Middle Stone Age. These are common components in the lithic industries, but are not often the subject of a specific interdisciplinary study associating functional technology, typology and traceology with environmental contextualization. Such comprehensiv...

Bifacial points are widespread tools over the northern half of the African continent during the Middle Stone Age. They are common components in the lithic industries, but are not often the subject of a specific interdisciplinary study associating functional technology, typology and traceology, and environmental contextualization. Such comprehensive...

Le présent rapport de la campagne 2017 au Sénégal oriental, menée dans le cadre du programme international « Peuplement humain et paléoenvironnement en Afrique », intègre les résultats de deux projets complémentaires : le projet ANR-FNS CheRCHA, ainsi que le projet FNS Falémé. Le premier vise à reconstituer le cadre chronostratigraphique et les évo...