Comportement électoral ; Etats-Unis ; Géographie de l'Amérique ; Géographie politique ; Indiana ; Milieu social ; Religion ; SouthBend ; Statut social ; Voisinage
Analyse de comportement électoral qui vise à déterminer les influences respectives de l'environnement social (voisinage), et de la croyance ou pratique religieuse sur les résultats de l'élection présidentielle de 1984 à SouthBend, Indiana.
The Geul River, located in the south-eastern part of The Netherlands, is a meandering river with a planform shape characterized by large loops consisting of multiple bends. The AA. evaluate the effects of groundwater flow on the shapes of meanders
as a possible explanation for the multi-bend loops, using a combined meandering-groundwater computer model. In the model seeping groundwater enhances bank erodibility.
Flow fields in tightly curving meander bends of low width-depth ratio
Australie ; Cours d'eau ; Ecoulement fluvial ; Erosion des berges ; Géométrie hydraulique ; Méandre ; New South Wales ; Transport sédimentaire
Australia ; Bank erosion ; Channel geometry ; Meander ; New South Wales ; Sediment transport ; Stream ; Stream flow
This paper documents the flow structures that result from the unsually narrow cross-sectional geometries and highly sinuous peatland changes at Barrington Tops (200 km north of Sydney) at flows measured up to bankfull. Two subsets of these bends
are presented for one bend with a meander pool; inward shifting of the maximum velocity filaments and limited sediment supply are proposed as mechanisms for the development and maintenance of these features. These flow data in narrow and deep peatland channels
[b1] Univ. of New South Wales, Canberra, Australie
A mathematical model for the geometry of meander bends in Geomorphological models. Theoretical and empirical aspects.
An attempt is made to deduce a general function for the approximation of the geometry of meander bends in the plane of the valley floor, in which no restriction for the geometry is made. Two cases must be distinguished : 1) the amount
of the migration of the meander bend downvalley is the same at each point of the bend| 2) the amount of that migration is not the same at each point of the bend. For case 1 it is possible to deduce a certain type of an approximation function. That is not possible
aléatoire au choix du logement et à la décision de déménager. Résultats d'une étude empirique sur des enquêtes faites auprès des ménages à SouthBend, Indiana.
Argentina ; Bolivia ; Braided channel ; Carrying capacity ; Channel geometry ; Discharge ; Hydrodynamics ; Meander ; Papua New Guinea ; Paraguay ; Regression analysis ; South America ; Stream ; Suspended load ; Tropical zone
This study applied binary logistic regression analysis to determine whether it is possible to predict chute initiation based on attributes of meander bend character and dynamics. Regression models developed for the Strickland River, Papua New Guinea
, the lower Paraguay River, Paraguay/Argentina, and the Beni River, Bolivia, revealed that the probability of chute initiation at a meander bend is a function of the bend extension rate (the rate at which a bend elongates in a direction perpendicular
Lateral sediment transport by bedforms in a meander bend
A case study has been carried out in the Danish river Gels Å in a bend with equilibrium point bar topography. The purpose is to map primary and secondary bedforms and bedform migration in a meander, and to measure the actual rate of the lateral
(lateral = perpendicular to the mean flow direction) transport in the bend.
Influence of experimental removal of large woody debris on spatial patterns of three-dimensional flow in a meander bend
This study reports the results of a large woody debris (LWD) removal experiment in a meander bend along a low-energy stream in the Midwestern United States. The results indicate that the LWD obstruction influenced 3D flow structure in this bend
at all flow stages. After the removal of LWD from the bend, both downstream and secondary velocities increased and, though still weak, secondary flow intensified.
Channel changes on the Macquarie Rivulet, New South Wales
Australie ; Chenal ; Cours d'eau ; Crue ; Géographie physique ; Hydrodynamique ; Macquarie Rivulet ; Morphométrie de chenal ; New South Wales ; Réseau de drainage
Recent work on stream channels near Sydney, New South Wales, suggests that the dominant discharge model is inadequate in this climatic regime, as at least two sets of flow are responsible for major channel forms. Evidence of channel geometry
the meander pattern has changed during infrequent high magnitude flows and it seems that the size of these bends is an adjustment to events that are catastrophic by world standards, but which occur here at least once every 25 years.
Distribution of large woody debris along the outer bend of meanders in the Ain River, France
The distribution of large woody debris (LWD) was studied along the concave outer bend of 3 meanders in the Ain River. The Ain River is a sixth-order channel dominated by a gravel-cobble bed substrate that meanders through a floodplain covered
largely by riparian forest vegetation. The total LWD deposited along concavities was most strongly controlled by meander-bend geometry. Findings from this study are applicable to restore alluvial forests along French rivers.
Grain-size sorting in meander bends containing large woody debris
This study examines the influence of large woody debris, LWD, on grain-size sorting in 3 meander bends in a low-gradient river in the Midwestern United States, in northern Illinois. The detailed nature of the modifications appears to be highly
dependent on the particular arrangement of LWD in a bend.
Spatial variability of three-dimensional Reynolds stresses in a developing channel bend
Experimental results of the mean flow field and turbulence characteristics for flow in a model channel bend with a mobile sand bed are presented. Acoustic Doppler velocimeters (ADVs) were used to measure the three components of instantaneous
velocities at multiple cross sections in a 135° channel bend for two separate experiments at different stages of clear water scour conditions. With measurements at multiple cross sections through the bend it was possible to map the changes in both the spatial
This paper uses evidence of 4 dates of aerial photography combined with annual field mapping and ground photography to examine the morphological changes and mechanisms of change in a series of bends on an active meandering river, the River Dane
of morphological change are illustrated for 4 types of bends: new, rapid growth bend; sharp-angled bend with mid-channel bar development; symmetric migrating bend; and simple to compound bend development. The changes take place in phases that are not simply related
to discharge but to inherent sequences and feedbacks in development of bars and bend morphology and timescales for these are identified.
Influences of coarse bank roughness on flow within a sharply curved river bend
This paper examines how bank roughness from vegetation influences the near-bank velocity and the secondary current in particular. Understanding this influence is important because these aspects of flow in a bend have a significant part in governing
Fossil insect evidence for late Quaternary climatic change in the Big Bend region, Chihuahuan Desert, Texas
This paper discusses the results of insect fossil studies from the Chihuahuan Desert region, along the Rio Grande River in and around Big Bend National Park, Texas. Insects indicative of more severe aridity are first recorded at about 6 000 yr B. P
Computational fluid dynamics as a tool for investigating separated flow in river bends
This paper illustrates, firstly, how a computational fluid dynamics (CFD) program may be used to reproduce the qualitative features of the mean flow in a real river bend to allow testing of the model's capabilities. It is then shown how the CFD code
may be used to construct hypothetical channel bends which allow the experimentation necessary to investigate the controls on the extent of the separated flow.