The implications of spatial variability in surface seal hydraulic resistance for infiltration in a mound and depression microtopography
The aim of this experiment was to determine the influence of runoff depth on infiltration rate in the presence of a surface seal varying in hydraulic characterisrics with microtopography. Two soils, a Blosseville (Pays de Caux) silt loam
and Villamblain (Petite Beauce) silty clay loam were collected from the A horizon. The results provide a suitable explanation for field observations of increasing infiltration rate with either increasing rainfall intensity or runoff rate.
Large bedforms and associated hydraulic conditions within microtidal-inlet channels, southern Gulf of St. Lawrence, Canada
Différents types de macroformes de litage, à deux échelles de grandeur (mégarides de sable, dunes) apparaissent dans les gorges des petits chenaux de goulets balayés par des micromarées. Les plus grandes formes (longueur 32 m et hauteur 1 m) restent
orientées conformément au reflux durant tout le mois lunaire, cependant elles sont modifiées par les grandes marées. Les plus petites formes, parfois superposées sur les grandes, sont partiellement remaniées par chaque cycle de marée, et elles aussi gardent
Complex confining layers. A stochastic analysis of hydraulic properties at various scales
This volume presents a study of the problem of characterizing the hydraulic properties, i.e. hydraulic conductivity and effective porosity, and ground water flow of complex confining layers at various scales. The study has shown that it is possible
to derive representative hydraulic properties at the scale of model blocks, from hydraulic properties measured at the score scale. - (AGD)
Aridité, oasis et petite production, exigences hydrauliques et fragilité sociale : une approche par analyse spatiale et socio-économique
Aménagement hydraulique ; Désert ; Développement économique ; Equilibre écologique ; Mise en valeur ; Oasis ; Petit producteur
Desert ; Ecological equilibrium ; Economic development ; Hydraulic works ; Land development ; Oasis
Malgré la diversité des aménagements hydrauliques, l'évolution sur la longue durée des oasis échelonnées du Sahara à l'Asie centrale révèle que les situations sociales sont assez proches. Une grande partie de la population, notamment les petits
The effects of shifting cultivation on stream channel size and hydraulic geometry in small head-water basins of southwestern Nigeria
L'élargissement des chenaux alluviaux se produit lors de changements dans le régime d'écoulement accompagnant la destruction de la forêt naturelle pour la mise en valeur dans de petits-bassins-versants dans le sud-ouest du Nigéria. La relation
Action anthropique ; Ajustement ; Bilan sédimentaire ; Crue ; Delta ; France ; France du Sud-Est ; Géométrie hydraulique ; Holocène ; Lit fluvial ; Niveau marin ; Paléohydrologie ; Petit âge glaciaire ; Rhône
channels of the Rhone Delta. By using methods such as sedimentological evidence, historical sources, planimetric resurvey, repeated longitudinal and cross-profiling and hydraulic data, the geomorphological and hydraulic responses to channel changes
Flux et crues singulières d'un petit cours d'eau andin ou les effets pervers de l'urbanisation
Bolivia ; Canal ; Flood ; High mountain ; Hydraulic works ; Hydrodynamics ; La Paz ; Natural hazards ; Stream ; Stream flow ; Urbanization ; Watershed
Sur un petit bassin de haute montagne (4000 m), situé dans les Andes à proximité de La Paz, la canalisation des rios en vue de gagner des terrains urbanisables, a fortement modifié leur régime d'écoulement et leur comportement en crue, provoquant
L'A. relate le conflit qui oppose radicalement deux conceptions de l'économie et de la société au Québec (bassins-versants de la Grande et de la Petite rivières de la Baleine). Il décrit les réactions d'hostilité de la part des Amérindiens à l'égard
A partial explanation of the dependency of hydraulic conductivity on positive pore water pressure in peat soils
Part of the relationship between positive pore water pressures and hydraulic conductivity in peat soils may be explained by accumulations of methane bubbles. The AA. show how compression and expansion of gas bubbles with changes in pore water
pressure could cause changes in hydraulic conductivity and thus help to explain some observations of dependency of hydraulic conductivity in peats on pore water pressure. Consideration is also given to the effect on hydraulic conductivities of methane gas
Hydraulics of interrill overland flow on rough, bare soil surfaces
A set of laboratory experiments on bare, rough soil surfaces was carried out to study the relationship between soil surface roughness and its hydraulic resistance. A new model is developed to predict the hydraulic resistance of the surface, based
on detailed surface roughness data. Roughness profiles perpendicular to the flow are used to calculate the wet cross-sectional area and hydraulic radius given a certain water level. The algorithm of Savat is then applied to calculate the hydraulic resistance
Hyraulic heroes : the ironies of utopian hydraulism and its politics of autonomy in the Guadalhorce Valley, Spain
Andalusia ; Autonomy ; Historical geography ; Hydraulic works ; Irrigation ; Local knowledge ; Málaga ; Spain ; Water management
Dans cette vallée de la province de Malaga, un système traditionnel d'irrigation géré par de gros exploitants agricoles a été florissant depuis l'époque arabe. Les communautés locales, en dérivant de l'eau, ont géré de nombreux systèmes à petite
Petits barrages et lacs collinaires, aménagements originaux de conservation des eaux et de protection des infrastructures aval : exemples des petits barrages en Afrique du Nord et au Proche-Orient
Africa ; Arid area ; Asia ; Dam ; Hydraulic works ; Irrigation ; Lebanon ; Mediterranean States ; Northern Africa ; Semi-arid area ; Soil conservation ; Southwest Asia ; Syria ; Water management
A partir des exemples du Maroc, de la Tunisie, du Liban et de la Syrie, les AA. proposent une vaste synthèse sur la place des petits barrages dans la mobilisation et la gestion des ressources en eau et en sol dans les milieux méditerranéens semi
Hydraulics of sediment-laden sheetflow and the influence of simulated rainfall
This paper evaluates and compares hydraulic characteristics in flows with and without rainfall disturbance. The spatial uniformity of simulated rainfall properties, and its significance to flow hydraulics, are also discussed.
Sustained storage and transport of hydraulic gold mining sediment in the Bear River, California
This study examines the large deposits of hydraulic gold mining sediment and reevaluates Gilbert's (1917) classic model of sediment transport in a symmetrical wave that is based on hydraulic mining sediment primarily in the Yuba Basin. Sustained
storage and transport of hydraulic mining sediment in the Bear Basin are documented and a revised model of sediment transport is proposed.
Flow-separation berms downstream of a hydraulic jump in a bedrock channel
The purpose of this paper is to report the first direct observation of the phenomenon of gravel berm formation, downstream of a hydraulic jump. As the observations were fortuitous, detailed measurements of hydraulic conditions were not possible
but estimates were obtained. These observations are compared with laboratory experiments and theory. The deposits have significance in constraining flood palaeoflow reconstructions as the presence of berms determines the former location of hydraulic jumps.
Estimating unsaturated hydraulic conductivity from easily measured soil properties
The authors measured hydraulic conductivity (saturated and unsaturated) on 127 soil cores, which were taken in different horizons of a wide variety of Belgian soil series. The hot air method and the crust method were combined to obtain the complete
range of hydraulic conductivity from saturation to air-dry. Regression equations for estimating the Gardner parameters were established from simple soil properties, such as soil texture, carbon content, bulk density. Three parameters can reasonably well
be estimated from the textural composition and the saturated hydraulic conductivity.