نتایج جستجو برای: fluvial current
تعداد نتایج: 781632 فیلتر نتایج به سال:
Proterozoic rivers flowed through barren landscapes, and lacked interactions with macroscopic organisms. It is widely held that, in the absence of vegetation, fluvial systems featured barely entrenched channels that promptly widened over floodplains during floods. This hypothesis has never been tested because of an enduring lack of Precambrian fluvial-channel morphometric data. Here we show, th...
Rivers of the Coastal Plain of the southeastern United States are characteristically low-gradient meandering systems that develop broad floodplains subjected to frequent and prolonged flooding. These floodplains support a relatively unique forested wetland (Bottomland Hardwoods), which have received considerable ecological study, but distinctly less hydrogeomorphic study. The hydroperiod, or an...
The Benin Formation is well exposed along the Atamiri River, which traverses Uli town, in the Niger Delta Basin of Southeastern Nigeria. Lithologic sections were measured, described and sampled so as to decipher the paleodepositional environment, using an integration of lithofacies data, pebble morphology, grain size and paleocurrent analysis. The lithofacies study suggests that the Benin Forma...
Extended abstract 1- Introduction Fluvial and aeolian processes are important factors in changing the surface of morphology in the Earth. When rivers and sand dunes meet, the transportation of sediment between them can lead to one of the systems or both of them change. With their connection between river sediment and wind systems there would be lots of reactions, but very little has been st...
Starting from traditional ideas on the climatic steering of fluvial system dynamics, it appears that there are different kinds of climatic influences on system dynamics. They vary from direct climatic forcing (like peak precipitation) to indirect (like permafrost) and partial forcing (like vegetation). Vegetation (or its absence), and not directly climate, is considered as the main cause of flu...
River-response and Terrace Agradation in the Mediterranean Iberian Peninsula during Historical Times
Mediterranean fluvial environments have responded sensitively to past changes in climate, physiographic conditions and human activity. Chronosequences of river terraces and alluvial deposits were established using morphologic, sedimentological and pedologic criteria, Cand Pb-dating techniques, historical data and pottery fragments. The objective of this study addresses the fluvial dynamic of se...
Introduction: In the search for life on Mars, investigating fluvial deposits will be a high priority for future landers. Although there is abundant evidence that fluvial processes worked with great intensity in the past (e.g., outflow channels, valley networks, and modified impact craters), aeolian processes dominate under the current environmental conditions. In fact there is evidence that ext...
XBeach is an open source, freely available two-dimensional code, developed to solve hydrodynamic and morphological processes in the coastal environment. In this paper the code is applied to ten different test cases specific to hydraulic problems encountered in the fluvial environment, with the purpose of proving the capability of XBeach in rivers. Results show that the performance of XBeach is ...
In the Weichselian, the Lower Rhine in the Dutch-German border region has used three courses, dissecting ice-marginal topography inherited from the Saalian. In the Late Weichselian, the three courses functioned simultaneously, with the central one gaining importance and the outer ones abandoning. This study aims to reconstruct the fluvial development and forcings that culminated in abandonment ...
This paper characterizes the detailed sedimentology of a fluvial sandbody on Mars for the first time and interprets its depositional processes and palaeoenvironmental setting. Despite numerous orbital observations of fluvial landforms on the surface of Mars, ground-based characterization of the sedimentology of such fluvial deposits has not previously been possible. Results from the NASA Mars S...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید