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Landslides along a 10 km reach ofThompson River southofAshcroft, British Columbia, have repeatedly damaged vital railway infrastructure, while also placing public safety, the environment, natural resources, and cultural heritage features at risk. Government agencies, universities, and the railway industry are focusing research efforts on a representative test site--the very-slow-moving Ripley Landslide--to manage better the geohazard risk in this corridor. We characterize the landslide's form and function through hydrogeological and geophysical mapping. Field mapping and exploratory drilling distinguish 10 hydrogeological units in surficial deposits and fractured bedrock. Electrical resistivity tomography, frequency domain electromagnetic conductivity measurements, ground-penetrating radar, seismic pressure wave refraction, and multispectral analysis of shear waves; in conjunction with downhole measurement of natural gamma radiation, induction conductivity, and magnetic susceptibility provide a detailed, static picture of soil moisture and groundwater conditions within the hydrogeological units. Differences in electrical resistivity of the units reflect a combination of hydrogeological characteristics and climatic factors, namely temperature and precipitation. Resistive earth materials include dry glaciofluvial outwash and non-fractured bedrock; whereas glaciolacustrine clay and silt, water-bearing fractured bedrock, and periodically saturated subglacial till and outwash are conductive. Dynamic, continuous real-time monitoring of electrical resistivity, now underway, will help characterize water-flow paths, and possible relationships to independently monitor pore pressures and slope creep. These new hydrogeological and geophysical data sets enhance understanding of the composition and internal structure of this landslide and provide important context to interpret multiyear slope stability monitoring ongoing in the valley. Key words: surficial mapping, geophysical surveys, landslide, geohazard monitoring, British Columbia. Les glissements de terrain le long d'un troncon de 10 km de la riviere Thompson au sud d'Ashcroft (Colombie-Britannique) ont cause des dommages a repetition a des infrastructures ferroviaires essentielles, tout en posant des risques pour la securite du public, le milieu ambiant, des ressources naturelles et des elements du patrimoine culturel. Des agences gouvernementales, des universites et le secteur ferroviaire ont axe des efforts de recherche sur un site d'essai representatif, le glissement tres lent de Ripley, afin de mieux gerer les georisques le long de ce corridor. Nous caracterisons la forme et la fonction de ce glissement a la lumiere de la cartographie hydrogeologique et geophysique. La cartographie de terrain et le forage d'exploration permettent de distinguer 10 unites hydrogeologiques dans les depots de surface et le roc fracture. La tomographie electrique, des mesures de conductivite electromagnetique en domaine de frequence, le georadar, la refraction des ondes sismiques de compression et l'analyse multispectrale des ondes de cisaillement, combines a la mesure au fond de puits du rayonnement gamma naturel, de la conductivite par induction et de la susceptibilite magnetique, fournissent un portait statique detaille de l'eau dans le sol et des conditions associees a l'eau souterraine dans les unites hydrogeologiques. Les differences de resistivite electrique entre unites refletent une combinaison de caracteristiques hydrogeologiques et de facteurs climatiques, a savoir la temperature et les precipitations. Les materiaux resistifs comprennent des depots d'epandage fluvioglaciaire secs et le roc non fracture, alors que les argiles et silts glaciolacustres, le roc fracture contenant de l'eau et du till infraglaciaire et des depots d'epandage periodiquement satures sont conducteurs. La surveillance continue et dynamique en temps reel de la resistivite electrique actuellement en cours aidera a caracteriser les voies d'ecoulement de l'eau et les relations possibles avec la pression interstitielle et la reptation de talus, qui font l'objet d'une surveillance independante. Ces nouveaux ensembles de donnees hydrogeologiques et geophysiques ameliorent la comprehension de la composition et de la structure interne de ce glissement de terrain et fournissent un important contexte pour l'interpretation des donnees issues de la surveillance pluriannuelle de la stabilite en cours dans la vallee. [Traduit par la Redaction] Mots-cles : cartographie de surface, leves geophysiques, glissement de terrain, surveillance des georisques, Colombie-Britannique., Introduction For many countries around the world, rail transport is the dominant mode for transporting natural resources to and from deepwater marine terminals, and transporting commuters and tourists to and [...]

Vegetation is important for managing shallow geotechnical assets. However, root water uptake-driven changes in slope hydrology and the near-surface (soil water content, matric suction, and hydraulic conductivity) are highly complex. Improved knowledge of these processes is increasingly important as society faces the threat of a greater prevalence of climate-driven extreme rainfall and drought events. Intrinsic factors affect slope stability, including geometry, soil properties, groundwater, and vegetation-driven matric suction. Field evidence shows that engineered slopes are susceptible to hydrometeorological instability mechanisms and pose a potential failure hazard to asset operation and public safety. This study considers the combination of a novel geophysical monitoring system and geotechnical point sensors for use in controlled laboratory conditions to assess the influence of vegetation on soil-water dynamics in the context of geotechnical infrastructure. The geophysical monitoring system, referred to here as PRIME (Proactive Infrastructure Monitoring and Evaluation system), uses electrical resistivity tomography (ERT) technology to non-invasively image changing subsurface moisture-driven processes. The PRIME system and point sensor arrays are being developed for near real-time data acquisition of transient soil moisture conditions in a suite of soil column experiments. Through addressing the challenges associated with designing integrated geophysical-geotechnical laboratory-scale monitoring experiments, this research aims to provide new tools and approaches to further our understanding of vegetation-driven soil moisture movement to better assess slope instability risk.

Deterioration within desiccated, clay infrastructure embankments can originate from two processes: (A) preferential flow through cracks allowing deeper and faster propagation of wetting fronts, and (B) microstructural degradation, reducing soil water retention capacity. These processes are interrelated, and together act to increase surface layer exposure to intense mechanical weathering and therefore, risk of asset failure. Desiccation induced deterioration is set to intensify under future climate change projections, heightening the need to understand how these processes develop within, and deteriorate, embankment fill over time. To address this, long-term hydrological and desiccation crack monitoring of a large-scale slope, constructed within an outdoor lysimeter, has been carried out under both natural, and simulated, climatic conditions. Initial findings illustrate a highly desiccated slope has the capacity to accept a large volume of storm rainfall prior to crack closure. This volume is set to increase due to the progressive aggregation and reduction in SWR behaviour observed within the slope. The importance of antecedent conditions, both in terms of crack geometry and initial degree of saturation, at the onset of rainfall, additionally proved important as it controls the depth and magnitude of VWC change in the slope. Continued monitoring of the slope will aid our understanding of the temporal evolution of these deterioration processes.

Composite barrier systems, which are two-layer systems of materials (fine-grained material overlying coarse-grained material) of contrasting hydraulic properties, can be used to mitigate the effects of climate change in urban areas, including flooding and shrink swell deformation. Here, a series of experiments were carried out to test a range of materials, including 20-30 mm gravel, recycled crushed concrete, topsoil, and topsoil amended with water treatment residual (WTR). The consideration of waste products here aims to improve the sustainability of composite barrier systems for climate adaptation. The results indicate that WTR-amended topsoil is suitable for use as a fine-grained material in composite barrier systems owing to its enhanced water retention properties. However, while crushed concrete can be used in the coarse-grained layer to form a capillary barrier when the system is dry, once breakthrough has occurred, transmission of water through the barrier is quicker than in composite barriers with 20-30 mm gravel. As such, 20-30 mm gravel is recommended for use in the coarse-grained layer. Two large-scale, outdoor lysimeters were set-up using the recommendations derived from the column experiments. The lysimeter experiments were subjected to a series of simulated rainfall events to enable initial interpretations of composite barrier performance.

The authors provide a guide to the thinking of the editorial collective for the Content section of the "Journal of Economic Education (JEE)". They discuss the type of papers they are looking for, what in their view constitutes a good paper, and how their review process works. They also provide some examples of what works (and what does not). Although they focus specifically on Content articles for the "JEE", many of the general issues discussed may carry over to other sections of the "JEE" and to journals more generally. (Contains 1 note.)

Examines the demand for schooling in Pakistan, focusing on two potential sources of bias in the estimation of that demand: censoring bias and selection bias. Finds evidence of both biases. (Contains 51 references.) (PKP)