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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Palaeoecology and sedimentology of Waulsortian 'reefs' (Lower Carboniferous)

Morgan, Nina January 1980 (has links)
Palaeoecological and sedimentological analysis has been applied in the study of Lower Carboniferous Waulsortian 'reefs' exposed in the Manifold Valley, North Staffordshire and in the Meuse Vallley in southern Belgium. Because Waulsortian 'reefs' have similar faunal, lithological and palaeogeographical characteristics in all of their occurrences it is argued that conclusions drawn from the Manifold and Meuse Valleys are applicable to the facies as a whole. Evidence is presented to show that lithological facies previously recognised within the Belgian Waulsortian can also be recognised elsewhere, and that changing sedimentation rates can explain many of their characteristic differences. Faunal and seimentological evidence indicates that the rate of sedimentation increased as the mounds developed. It is argued that the mound sediment was produced in situ and faunal data suggests that the surface of the mounds was firm. Early submarine lithification is thought to have been an important process in producing firm substrates and in maintaining steep depositional slopes. Fabrics and lithological components suggestive of early lithification have been recognised. A general model for Waulsortian development, based on conclusions drawn in this thesis, is presented.
2

Aléa climatique et régime hydrologique dans le bassin transnational de la Meuse : co-variabilité, changements possibles et impact sur les débordements / Climate hazard and streamflow discharges in the transnational Meuse river basin : co-variability, possible changes and impact on river overflowing

Grelier, Benjamin 01 December 2017 (has links)
Le changement climatique requiert une adaptation de la gestion des extrêmes hydrologiques (crues et étiages). Nos recherches proposent un cadre d’analyse de l’effet du changement climatique sur ces extrêmes dans le bassin transnational de la Meuse, par un chaînage de modèles (atmosphérique – hydrologique - hydraulique) liant le gradient régional de pression à l’écoulement mesuré à l’exutoire d’un bassin. Le forçage climatique est obtenu par l’agrégation de données climatiques historiques et de données multi-modèles issues de l’expérience CMIP5. En forçant deux sous-bassins de la Meuse (situés en France et en Belgique) à l’aide d’une première estimation de la variabilité climatique potentielle, nous montrons que les indicateurs de crues et d’étiages ainsi que les débordements de rivière peuvent être fortement impactés par le changement climatique anthropique. Cette analyse de vulnérabilité constitue un outil pour tester la robustesse de stratégies d’adaptation au changement climatique / Climate change requires to adapt management of streamflow extremes (floods and low flows). Our researches provide a framework to analyze climate change effect on the streamflow extremes in the transnational Meuse river basin, through a modelling chain (atmospheric model – hydrological model – hydraulic model) linking the pressure gradient force to the flow at the outlet of a basin. The climate forcing is obtained by blending historical data and multi-model data for the CMIP5 experience. By forcing two sub-basins of the Meuse river (located in France and Belgium) with the potential climate variability, we show that flood and low flows indices as well as river overflowing might be strongly impacted by the anthropogenic climate change. This analysis of catchment vulnerability is a robust tool to test climate resiliency of adaptation strategies for water management
3

L'âge du Bronze final dans les bassins de l'Escaut et de la Meuse moyenne: culture matérielle et cadre socio-économique / Late Bronze Age in the Scheldt and Middle Maas basins: material culture and socioeconomic environment

Leclercq, Walter 30 March 2012 (has links)
Dès le Bronze final, on assiste en Europe occidentale à la mise en place d’une géographie culturelle qui positionne les bassins de l’Escaut et de la Meuse moyenne à la charnière des grands complexes traditionnels :atlantique, nordique et continental. <p>Par l'étude du mobilier céramique issu de sites en grande partie inédits (provenant à la fois de fouilles récentes et anciennes) de l'aire géographique considérée, l'objectif principal de notre thèse était de déterminer le paysage socio-économique, son évolution au cours du temps et finalement son insertion dans une mouvance européenne. Des questions sur la circulation des biens mais également sur celle des populations sont dès lors soulevées.<p>\ / Doctorat en Histoire, art et archéologie / info:eu-repo/semantics/nonPublished

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