A rational explanation of cross-profile morphology for glacial valleys and of glacial valley development : a further note
The AA. discovered a misinterpretation in their original paper entitled : a rational explanation of cross-profile morphology for glacial valleys and of glacial valley development in earth surface processes and landforms, vol. 13, No 8, p. 707-716
Outlines of the late Quaternary history of the Drentsche Aa Valley (Drente, The Neteherlands)
An outline is given of the geomorphology and Late Quaternary history of the Drentsche Aa valley. The valley sediments are subdivided in fluvial, slope and aeolian sediments on lithological arguments. The vertical succession of the river valley
sediments demonstrates a decreasing fluvial activity during the Weichselian. Tentatively four erosion phases are distinguished in the valley system.
This paper aims to explore the process-landform relationships and potential genetic links between duricrust formation and Kalahari valley development, and hence assess the possible influence and implications of groundwater weathering and erosion
upon duricrusts. This is achieved by consideration of relationships between valleys and duricrusts at a variety of scales (ranging between microscale to valley scale) from three mekgacha systems within the Kalahari: the Rooibrak and Letlhakeng valleys
Problems in automated recognition of valley features from digital elevation models and a new method toward their resolution
Drainage network ; Greece ; Hydrology ; Landslide ; Model ; Numerical model ; Peloponnesus ; Valley
In this paper a new method for recognizing valley bottoms is presented. This is based on two improvements of Carroll's (1983) method, and produces a network that reflects the topography well. The network is used to locate valley heads. Once located
, the valley heads are delineated using criteria suggested by geomorphologists and hydrologists. The resultant valley heads are generally well recognized although two problems are evident : a) there are a number of commission errors; and b) the valley heads
Automated recognition of valley heads from digital elevation models
An automated technique for recognizing valley heads from digital elevation models is presented. The technique has been developed for valley head recognition because valley heads are known locations of geomorphological activity and because areal
features have been largely ignored in the automated landform recognition literature. The problem of valley head recognition is divided into valley head location and valley head delineation, and the technique is developed using a DEM representing a simple
This article indicates the quantitative tools, with assistance of which it is possible to characterize the morphology (shape) of the valley network and determine their variability caused by the scale change. The monitored morphometric
characteristics (quantitative tools) have been applied to the paradigmatic examples of the schematic valley networks and have been analyzed in three scales. In order to analyze the valley networks, the most suitable are “valley junction angles” and “homogeneity
of various order valleys”, where the relevant values dropped while increasing the scale, but the normal (Gauss) distribution of values was preserved. - (EN)
Valleys and river benches from the viewpoint of morphotectonics
Concept ; Fluvial processes ; Hydrogeology ; Valley
The geomorphological concepts on the formation of valleys and river benches applied until now have been based upon the viewpoints of dynamic and climatic geomorphology. This exogenous interpretation should be abandoned and an endogenous concept
Valley asymmetry on south-eastern Alexander Island, Antarctica, and valley forms in the High Drakensberg, Southern Africa
Africa ; Antarctica ; Cold area ; Earth surface processes ; High mountain ; Model ; Pleistocene ; Quaternary ; Slope ; Southern Africa ; Valley
Field data from Alexander Island, Antarctica, are used to develop a model for the formation of asymmetrical valley-side slopes. The application of the model to high altitude valley slopes formed in the Pleistocene in the Drakensberg is considered
The evolution of the Vistula river valley between Cracow and Niepołomice in late Vistulian and Holocene times
Evolution of the Vistula river valley during the last 15 000 years, part IV
Alluvium ; Climatic variation ; Drainage network ; Fluvial processes ; Holocene ; Human impact ; Poland ; Quaternary ; Sedimentology ; Valley ; Valley floor evolution ; Wisła
This is a new synthesis of the evolution of the section of the Vistula river valley. There are changes in the channel patterns and parameters, sedimentological characteristics of the different alluvial deposits of different ages, the reflection
of both climatic fluctuation and human activity in the valley floor morphology and in alluvia. - (DG)
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.
Automated identification of yatsu valleys based on a semantic modeling of landforms using digital elevation models
Algorithm ; Classification ; Digital elevation model ; Geomorphology ; Honshu ; Japan ; Modelling ; Slope gradient ; Topography ; Topology ; Valley
The aim of this study is to develop algorithms for identifying Yatsu valleys by topological measurements based on the semantic modeling of landforms using a DEM. Yatsu valleys are valleys with flat floors dissecting into the uplands and hills
in Japan. The AA. have improved the algorithms to address previous shortcomings such as the difficulties in delineating the outlines and in measuring the gradient of the valley-floor.
Czech Republic ; Fluvial dynamics ; Fluvial processes ; Fluvial terrace ; Meander ; River bed ; Valley ; Valley floor evolution
Valley stretches abandoned by watercourses at Quaternary, represent district landforms of the fluvial erosion-accumulation relief in the northern part of the Bohemian Upland. Four abandoned valleys and numerous Ohře River meanders were discussed
Late Holocene valley-bottom aggradation and erosion in the South Loup River Valley, Nebraska
The chronology of aggradation and erosion is developed from ten radiocarbon ages. After discussing fluvial erosion and floodplain aggradation in the South Loup River Valley, the paper reconstructs the late Holocene alluvial records of the North
and Middle Loup River Valleys from published reports and articles.
On the formation of the tunnel valleys of the Superior Lobe, central Minnesota
The Minnesota tunnel valleys are composed of individual segments 10-20 km long, and the segments commonly terminate in subaerial outwash fans at recessional ice margin positions. Eskers, associated with the tunnel valleys, are also composed of short
segments, frequently beginning at moulin kames and terminating at the head of outwash fans. The dominant source of the water responsible for tunnel-valley formation was seasonal meltwater from the glacier surface that reached the bed through moulins
and crevasses. The apparent continuity of the valleys resulted from the headward development of the englacial drainage system during ice retreat.
Silicon Valley. Personlichkeiten und gesellschaftliche Ideen als raumgestaltende Kräfte (Silicon Valley. Des personnalités et des idées sociales comme moteur de l'aménagement)
Aménagement régional ; Didactique ; Enseignement de la géographie ; Généralités sur la géographie ; Innovation technologique ; Mythe Silicon Valley ; Pôle de croissance
Réflexions didactiques sur le mythe de la Silicon Valley. Prise en compte des facteurs techniques et économiques.
Experimental study of wind directional variability in the vicinity of a model valley
Aeolian features ; Aeolian transport ; Aerosol ; Atmospheric pollution ; Experimentation ; Modelling ; Topography ; Valley ; Wind ; Wind speed
This paper reports the results of a preliminary study examining the effects of valley presence on airflow direction and focuses on valleys situated in areas of low relief. Wind tunnel experiments are used to visualise near-surface airflow over
a series of models representing valleys oriented at different angles to mean airflow. This study has significance to the modelling of pollution dispersal and also aeolian sediment and nutrient dynamics in desert regions.
Hypsometric forcing of stagnant ice margins: Pleistocene valley glaciers, San Juan Mountains, Colorado
Colorado ; Deglaciation ; Glacial valley ; Glacier margin ; Hypsometry ; Model ; Mountain ; Pleistocene ; Quaternary ; Topography ; United States of America
The A. uses the location of stagnant ice deposits in many San Juan valleys, Colorado, to test how valley hypsometry and topographic obstructions influence the type of margin present during valley glacier retreat.
Valley asymmetry with steeper west-facing valley sides is a common feature in the Tertiary Hills of Lower Bavaria. The purpose of this study is to examine the relation between this drainage and valley asymmetry and to review the possible causes