Earth Sciences, Department of

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Groundwater—Surface Water Interactions in a Mountain-to-Coast Watershed: Effects of Climate Change and Human Stressors

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2015
Abstract: 

Watersheds located within a mountain to coast physiographic setting have been described as having a highly interconnected surface water and groundwater environment. The quantification of groundwater—surface water interactions at the watershed scale requires upscaling. This study uses MIKE SHE, a coupled numerical model, to explore the seasonally and spatially dynamic nature of these interactions in the Cowichan Watershed on Vancouver Island, British Columbia, Canada. The calibrated model simulates a transition of the Cowichan River from mostly gaining within the valley, to losing stream near the coast where groundwater extraction is focused. Losing and gaining sections correlate with geological substrate. Recharge across the watershed accounts for 17% of precipitation. Climate change is projected to lessen snowpack accumulation in the high alpine and alter timing of snowmelt, resulting in higher spring and winter river discharge and lower summer flows.

Document type: 
Article
File(s): 

Structural Interpretation of the Mamfe Sedimentary Basin of Southwestern Cameroon along the Manyu River Using Audiomagnetotellurics Survey

Author: 
Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2012
Abstract: 

Five audiofrequency magnetotelluric AMT soundings were collected northwest-southeast along the Manyu river in the Mamfe sedimentary basin of southwestern Cameroon. The soundings were performed with frequencies in the range 3 to 2500 Hz and covered a distance of approximately 28 km. Sounding curves and geoelectric and geological sections were processed, and the results were compared with rocks' resistivity to characterize the lithostratigraphy of the eastern part of the basin. The results show above 1000 m depth, sedimentary layers with resistivities in the range of 1 to 100 Ohm-m, which decrease with depth. We identified three types of sedimentary rocks: laterite-clay mixture, shale, and sandstones. Various faults were also identified, illustrating the structural complexity of the Mamfe basin, along the Manyu River.

Document type: 
Article
File(s): 

A Novel Approach to Modelling Water Transport and Drug Diffusion Through the Stratum Corneum

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2010
Abstract: 

Background: The potential of using skin as an alternative path for systemicallyadministering active drugs has attracted considerable interest, since the creation ofnovel drugs capable of diffusing through the skin would provide a great steptowards easily applicable -and more humane- therapeutic solutions. However, fordrugs to be able to diffuse, they necessarily have to cross a permeability barrier: thestratum corneum (SC), the uppermost set of skin layers. The precise mechanism bywhich drugs penetrate the skin is generally thought to be diffusion of moleculesthrough this set of layers following a “tortuous pathway” around corneocytes, i.e.impermeable dead cells.Results: In this work, we simulate water transport and drug diffusion using a threedimensionalporous media model. Our numerical simulations show that diffusiontakes place through the SC regardless of the direction and magnitude of the fluidpressure gradient, while the magnitude of the concentrations calculated areconsistent with experimental studies.Conclusions: Our results support the possibility for designing arbitrary drugs capableof diffusing through the skin, the time-delivery of which is solely restricted by theirdiffusion and solubility properties.

Document type: 
Article