Interactions between airflow and valley topography with implications for aeolian sediment transport
Aeolian features ; Aeolian transport ; Arid area ; Desert ; Model ; Namibia ; Topography ; Valley ; Wind ; Wind speed
This paper investigates the impacts of dryland valley topography on wind speed and direction in order to understand better the effects of a valley on aeolian sediment dynamics. Anemometers and wind vanes were used to measure airflow characteristics
upwind, within and downwind of a dry valley in the central Namib desert. A conceptual model indicating the potential implications of these data for aeolian sediment transport processes in the vicinity of dryland valleys is presented.
Silicon valley's innovative milieu : a cultural mix of entrepreneurs, an entrepreneurial mix of cultures ? Experiences of european firms.
California ; Culturel ; Décision ; Entreprise ; Etats-Unis ; Intégration économique ; Réseau ; Silicon Valley ; Technologie
La Silicon Valley regroupe une grande diversité de cultures entreprenariales due à la présence de nombreux entrepreneurs immigrants. Les AA. cherchent à savoir comment les firmes européennes s'intègrent à la Silicon Valley et quelles tensions en
Geomorphological features of the Bratica valley (Northern Apennines, Italy)
Appennino ; Geomorphogenesis ; Geomorphology ; Glacial features ; Italy ; Periglacial features ; Slope dynamics ; Valley
The geormophological survey of the valley of the River Bratica, the main affluent of the River Parma, has been carried out with the aim of improving the knowledge of the geomorphological development of the eastern part of the high Apennines of Parma
section. During the survey, all the processes responsible for the geomorphic evolution of the valley have been considered, with particular attention to those due to the glacial, periglacial and slope processes. - (NF)
The central area of the Apulia region is characterized by a network of valleys with peculiar features, locally called gravine or lame. They are short, straight valleys, deeply incised in Plio-Pleistocene calcareous sandstones and in Mesozoic
limestones. Morpholoical features and hydrogeological conditions suggest that sapping processes were responsible for the development of the valley network. Furthermore, the particular hydrogeological conditions of the region along with the Pleistocene glacio
-eustatic sea-level changes are taken into account, since they enhanced the development of the valley networks by sapping processes several times during the Middle-Upper Pleistocene.
Late Quaternary geomorphic evolution of the lower Narmada valley, Western India : implications for neotectonic activity along the Narmada-Son Fault
Drainage network ; Fault ; Geomorphology ; Gujarat ; India ; Neotectonics ; Quaternary ; Seismicity ; Stratigraphy ; Valley ; Vertical movement
Geomorphic data combined with stratigraphic studies provide significant information to constrain timing and amount of fault movement. The lower Narmada valley lies astride the Narmada-Son Fault (NSF), an important ENE-WSW-trending tectonic element
Narmada valley. The AA. discuss the geomorphic evolution of the lower Narmada valley in relation to neotectonic movements along the NSF.
Small valley bottom deposits in the sandy districts of the Sarthe basin (France) : climatic and/or human origin?
The A. reconstructs the geomorphic evolution of the small valleys through the analyses of recent and past infilling. The coarse alluvium with flints, which reached the main valleys prior to the Subboreal, was transported by greater flows than those
which resulted from later human-induced flood discharges, where flints were not evacuated from the small valleys. Radiocarbon dates of peat set those deposits in the Iron Age, in the transition from Antiquity to the Medieval period, at the end
of the optimum climatique de l'an Mil and during the Little Ice Age. Now, human-induced flood discharges reach again the main valleys.
Origin and palaeo-environments of calcareous sediments in the Moshaweng dry valley, southeast Botswana
Quaternary sedimentation in the Moshaweng dry valley of southeastern Botswana is evaluated on the basis of geomorphological evolution and sedimentological analyses. Stratigraphic evidence reveals an upper surface containing abundant sil-calcrete
palaeoenvironmental information and provide tentative dating relating to valley formation.
A mid-Holocene alluvial deposit beneath blanket peat in the upper Liffey Valley, County Wicklow, Ireland
This paper describes a recently exposed cross section of a small valley buried beneath blanket peat on the upper slopes of the Liffey valley in the Wicklow Mountains, eastern Ireland, and examines its significance to the understanding of early
Volcaniclastic debris flows in the Clanio valley (Campania, Italy) : insights for the assessment of hazard potential
In order to carry out a preliminary zonation of hazard potential in the Clanio Valley, the AA. performed a geological and geomorphological investigation immediately after May 6, 1998. The results focus on analysis of debris flow characteristics
in the Clanio Valley and on the criteria for hazard potential zonation in this area. Morphometric analyses were supported by a digital elevation model (DEM). By coupling field and computer-assisted data, the AA compiled a hazard zonation map of the Clanio Valley.
Aeolian dust contributions to soil on the Namoi Valley, northern NSW, Australia
of the lower Namoi River Valley, the AA. used a range of granulometric, mineralogical and geochemical methods. The AA. also examined contemporary data on dust deposition rates and compared characteristics of present-day dust with the soil materials.
Geomorphic studies of landslides in the Tully Valley, New York : implications for public policy and planning
This paper describes the effects of the 1993 landslide, reports on the results of several follow-up investigations and geomorphic studies, and examines the implications of the landslide for public policy and planning in the Tully Valley community.
Bern ; Cave ; Cave development ; Cenozoic ; Glacial erosion ; Karst ; Palaeogeography ; Palaeogeomorphology ; Springs ; Switzerland ; Th/U dating ; Valley
to spring level and to old valley floors. The results lead to the hypothesis that the uppermost (oldest) cave parts were already created in the Miocene, during and after the last deposition of the Molasse. Ideas about the evolution of the paleorelief suggest
that today's Aare valley is a product of glacial erosion, and that the old Aare valley shifted its position several times between the Miocene and today.
Holocene landscape history and palaeohydrology evidenced by stable carbon isotope (δ C 13)analysis of alluvial sediments in the Mbari valley (5°N/23°E), Central African Republic
and in the Mbari valley in the southeast of the Central African Republic. Secondly, it focuses on the impact of Quaternary environmental changes on geomorphological processes.
The AA. describe the tributary mouth sedimentation sites of the Kuiseb Valley near Homeb to illustrate slack water paleoflood hydrology. They document that the Homeb sites do not represent drier climates and weaker floods in the valley during