Filters: Tags: Earth Surface Processes and Landforms (X)
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A detailed review and chronological survey is presented of the various techniques which have been used for the measurement of river bank erosion and channel change. The techniques are classified according to the time scales involved (long, intermediate and short) and each is discussed with respect to accuracy and repeatability. The methods covered include sedimentological evidence, botanical evidence, historical sources, planimetric resurvey, repeated cross-profiling, erosion pins and terrestrial photogrammetry. Prospects for future developments are also discussed. Published in Earth Surface Processes and Landforms, volume 18, issue 9, on pages 777 - 821, in 1993.
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Channel migration,
Earth Surface Processes and Landforms,
Lateral channel change,
River bank erosion
Since the beginning of the Cenozoic period several hundreds of metres of the sedimentary cover have been removed from the Colorado Plateau. Palaeoclimatic considerations show that the Colorado Plateau has been dominated by dry climates throughout the Cenozoic with the possible exception of the early Palaeocene. Today in the still prevailing arid climate, which strongly accentuates differences in rock resistance, the relief shows a structurally controlled cuesta scarp topography in the slightly deformed strata of alternating resistance. In examining whether the denudational efficiency of scarp retreat was sufficient to account for the wide erosional gaps in the sedimentary cover, rates of scarp retreat were determined...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Cenozoic,
Colorado Plateau,
Cuesta scarps,
Earth Surface Processes and Landforms,
Rates of scarp retreat,
Mountain rivers can be subject to strong constraints imposed by changes in gradient and grain size supplied by processes such as glaciation and rockfall. Nonetheless, adjustments in the channel geometry and hydraulics of mountain rivers at the reach scale can produce discernible patterns analogous to those in fully alluvial rivers. Mountain rivers can differ in that imposed reach-scale gradient is an especially important control on reach-scale channel characteristics, as indicated by examination of North St Vrain Creek in Colorado. North St Vrain Creek drains 250 km2 of the Rocky Mountains. We used 25 study reaches within the basin to examine controls on reach-scale channel geometry. Variables measured included...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Earth Surface Processes and Landforms,
channel adjustment,
downstream hydraulic geometry,
mountain rivers
The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa ? surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Earth Surface Processes and Landforms,
Mojave Desert,
dust,
evaporite minerals,
playa,
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