Hydrology Seminar – Thursday 28 June, 10am

MSc candidate Chris Marsh will present a seminar on
Implications of mountain shading on calculating energy for snowmelt using unstructured triangular meshes

On Thursday June 28, 2012, at 10am, in 146 Kirk Hall
In many parts of the world, snowmelt energy is dominated by solar irradiance. This is the case in the Canadian Rocky Mountains, where clear skies dominate the winter and spring. In mountainous regions, solar irradiance at the snow surface is not only affected by solar angles, atmospheric transmittance, and the slope and aspect of immediate topography, but also by shadows from surrounding terrain. Accumulation of errors in estimating solar irradiation can lead to significant errors in calculating the timing and rate of snowmelt due to the seasonal storage of internal energy in the snowpack. Gridded methods are often used to estimate solar irradiance in complex terrain. These methods work best with high-resolution gridded digital elevation models (DEMs), such as those produced using LiDAR. However, such methods also introduce errors due to the rigid nature of the mesh, creating artefacts and other artificial problems. Unstructured triangular meshes, such as triangulated irregular networks, are more efficient in their use of DEM data than fixed grids when producing solar irradiance information for spatially distributed snowmelt calculations and they do not suffer from the artefact problems of a gridded DEM. This project demonstrates the use of a horizon-shading algorithm model with an unstructured mesh versus standard self-shading algorithms. A systematic over-prediction in irradiance is observed when only self-shadows are considered. This over-prediction can be equivalent to 20% of total pre-melt snow accumulation. The modelled results are diagnosed by comparison to measurements of mountain shadows by time-lapse digital cameras and solar irradiance by a network of radiometers in Marmot Creek Research Basin, Alberta, Canada.

Saskatchewan Water Table ‘Full Up’…

CH Prof Cherie Westbrook was interviewed for an article for Saskatoon Home Page on the current hydrological state of play in Saskatchewan: with an unprecedented amount of rainfall through the spring, on top of already wet soil, and a natural physiography not yet evolved to encourage ordered runoff, the water table is effectively ‘full up’.
The article is available here

Beaver Peatlands Blog

CH MSc student Alasdair Morrison is blogging about his field work experience in the Rockies this summer. His goal is to inventory Rocky Mountain peatlands, especially those infested with beaver: he is using ground penetrating radar to search for buried beaver paleoponds, to give us insight into beaver as a soil forming agent. The blog is at: dontrunfromthebears.blogspot.ca
In his words to supervisor Dr Cherie Westbrook: “I’m trying to keep it reasonably entertaining and funny, so I may be using a bit of exaggeration and artistic licence at some points for comedy effect. I just don’t want you to get worried about when I talk about trespassing, and getting lost etc! I’m hoping it comes off as a reasonably fun and honest (bar exaggerations) account of what happens during field work!”

Grand Slam for Nicholas Kinar!

CH PhD student Nicholas Kinar won the D.M. Gray Award at the 2012 Canadian Geophysical Union meeting in Banff, Alberta on June 8 for his paper and talk on Acoustic Imaging and Measurement of Snow.
Nicholas won the Horton Award from the American Geophysical Union in December 2011 and so is the first to achieve the ‘grand slam’ of North American hydrology awards.
Many congratulations, Nicholas!