Permeability across a metropolitan area : conceptualizing and operationalizing a macrolevel crime pattern theory
Criminality ; Delinquency ; Large city ; Metropolitan area ; Municipality ; Pennsylvania ; Permeability ; Philadelphia ; Social geography ; United States of America ; Violence
This article analyses permeability across a metropolitan area through conceptualizing and operationalizing a macrolevel crime pattern theory in the Philadelphia metropolitan area. Three municipality-level indices reflecting internal and boundary
permeability are developed that are internally consistent and cross reference in sensible ways with large-scale physical environment features of municipalities. Permeability indicators link as predicted with unexpected violent and property crime changes.
Aerodynamic entrainment thresholds and dislodgement rates on impervious and permeable beds
Using a range of grain sizes and flow conditions, the series of laboratory experiments reported here compares directly the aerodynamic entrainment of loose grains overlying fixed permeable sediment beds with that occurring over fixed impervious beds.
Korrelative Beziehungen zwischen Porosität und Durchlässigkeit in einem primär verdichteten und gelockerten Loss-Unterboden. (Correlations between porosity and permeability of a primarily compacted and loosed loess subsoil)
Vertical and horizontal permeability of morphologically different coarse-pore systems constitutes a decisive factor in assessing the ecological effect of soil structure forms. Porosity values are used in regression analysis to investigate
the permeability conditions of a natural and deep-loosed subsoil of an Albic Luvisol site. (HL).
Ecoulement de surface dans les bassins perméables du Sahel. Comparaison avec d'autres bassins perméables tropicaux
Travail visant à dégager des valeurs quantitatives intéressant l'écoulement superficiel dans le cas de très fortes averses sur les bassins perméables du Sahel assez mal connus. Toute l'information disponible dans les rapports originaux et les
Geostatistics ; Grain size distribution ; Permeability ; Sandstone ; Simulation ; Spatial variation ; United States of America ; Weathering
In this study, a range of geostatistical techniques for spatial prediction and spatial simulation have been deployed to explore the spatial variability of permeability characteristics. The effect of both small-scale textural controls (grain size
) and diagenetic processes on permeability variation will be investigated for Stanton Moor Sandstone.
A geostatistical investigation into changing permeability of sandstones during weathering simulations
Erosion rate ; Geostatistics ; Geotechnics ; Mid-latitude climate ; Model ; Northern Ireland ; Permeability ; Salt ; Sandstone ; Simulation ; United Kingdom ; Weathering
recorded at a series of stages from ongoing salt-weathering trials are used to investigate the spatial variation of trigger factors, such as permeability, and the establishment of positive feedback conditions in a temperate climate.
This study demonstrates the contrasting mechanisms of landslides in adjoining hills with permeable (sandstone) and impermeable (mudstone) bedrock in the Boso Peninsula. The characteristics of slope hydrology were inferred from pressure-head
Hydrogeology of Bermuda. Significance of an across-the-island variation in permeability
On distingue deux zones: une bande de calcaires, peu perméables, le long d'un littoral et une bande de calcaires plus anciens, plus perméable, le long du littoral opposé. La distribution symétrique le long d'un axe de l'eau douce souterraine est due
This paper describes an alternative ex situ core permeametry technique that is field based. The potential sources of precision and bias error within the method are quantified and their effect on the uncertainty of permeability estimates
Photointerpretation applied to hydrogeological problems: soil moisture content, soil permeability, hydrogeological structures in Remote sensing application in agriculture and hydrology.
Variations between the permeability properties of fresh rock and the same rocks after the early stages of a salt weathering simulation are used to examine the effects of salt accumulation on spatial variations in surface rock permeability properties
in 2 limestones from Spain. The Fraga and Tudela limestones are from the Ebro basin and are of Miocene age. Permeability mapping and statistical analysis before and after salt accumulation are used to assess changes in the spatial variability
of permeability and to correlate these changes with salt movement, porosity change, potential rock deterioration and textural characteristics. Statistical analyses of small-scale permeability measurements are used to evaluate the drivers for decay and hence aid
How the Quaternary climatic change affects present hydrogeological system on the Chinese Loess Plateau : A case study into vertical variation of permeability of the loess–palaeosol sequence
Aquifer ; China ; Climatic change ; Hydrogeology ; Loess ; Palaeosol ; Permeability ; Plateau ; Quaternary ; Semi-arid area ; Shaanxi ; Water resources
The results of in situ permeability measurements on the Luochuan Yuan (tableland), as a case study, illustrate that average infiltration rate of loess layers is higher than that of palaeosol layers, and that average time for the loess layers
to reach quasi-steady infiltration is longer than that of palaeosol layers. In addition, loess layers have higher porosity than palaeosols on average, and it is suggested as a major reason why the loess layers have a higher permeability on average
. The difference of permeability between loess and palaeosol layers facilitates the loess units more likely to be aquifers. In this regard, the Quaternary climatic change theory can make a contribution to hydrogeology of the Chinese Loess Plateau, and the regional
of the measurements of the primary rock permeability. The results indicate that the initial permeability contrast is not sufficient to explain alone the concentration of karst development along inception horizons. However, it is noticed that 3 types of inception
horizons can be distinguished: type 1, where cave inception took place within the inception horizon and where the permeability of the inception horizon was slightly higher than that of the surrounding rock mass; type 2, where inception took place
at the interface between the inception horizon and the surrounding rock mass, and where the permeability of the inception horizon is slightly lower than the surrounding rock mass; type 3, where the cave development took place along bedding plane fractures.
L'eau potable en haute montagne : contrôle des ressources par les milieux peu perméables fracturés. Exemples des Alpes de Savoie
perméables assurent la perennité des écoulements en eau potable. Les études sur ces milieux afin de mieux connaître leurs ressources et de mieux les exploiter devraient être multipliées spécialement dans les zones touristiques montagnardes dont les besoins en