The University of Saskatchewan and the Canadian Society for Hydrological Sciences will again be offering their successful intensive course on the physical principles of hydrology with particular relevance to Canadian conditions.
The course will take place at the University of Calgary Biogeoscience Institute’s Barrier Lake Station in the Kananaskis Valley from March 1-12, 2013.
Full details are available here. Demand is perennially high, so we must operate a policy of ‘first come, first served’!
Author Archives: Jin
Hydrology Seminar – Monday 16 July, 2pm
Dr Taufique Mahmood, of the Global Institute of Water Security and Centre for Hydrology, will present a seminar on
Hydrologic Spatial Patterns in a semiarid Ponderosa Pine hillslopes
on Monday 16 July, 2012, at 2:00pm, in Room 146 Kirk Hall
Ponderosa pine forests are a dominant land cover type in semiarid montane areas. Water supplies in major rivers of the southwestern United States depend on ponderosa pine forests as these ecosystems:
(1) receive a significant amount of rainfall and snowfall,
(2) intercept precipitation and transpire water, and
(3) indirectly influence runoff by impacting the infiltration rate.
However, the hydrologic patterns in these ecosystems with strong seasonality are poorly understood. In this study, we use a distributed hydrologic model to understand hydrologic patterns in a patchy ponderosa pine landscape. Our modeling effort is focused on the hydrologic responses during North American Monsoon (NAM) and winter to summer transitional period.
Our findings indicate that vegetation patterns primarily influence the hillslope hydrologic response during dry summer periods leading to patchiness related to the ponderosa pine stands. The spatial response patterns switch to fine-scale terrain curvature controls during persistently wet NAM periods. Thus, a climatic threshold involving rainfall and weather conditions during the NAM is identified in the hillslope response when sufficient lateral soil moisture fluxes are activated by high rainfall amounts and the lower evapotranspiration induced by cloud cover.
Our findings on the winter to summer transitional period indicate the importance of the relative wetness of each season. For a sequence with a wet winter and a dry summer, a robust snowpack results in abundant soil moisture in the hillslope that persists until the summer season when evapotranspiration consumes it. Under these conditions, the hillslope lateral transport becomes disconnected during the spring transition. We observe an opposite sequence of events when a dry winter is followed by a wet summer period. For each case, the spatial controls on hillslope hydrologic patterns are assessed relative to the terrain and vegetation distributions.
Results from this work have implications on the design of hillslope experiments, the resolution of hillslope scale models, and the prediction of hydrologic conditions in ponderosa pine landscapes. Further, the proposed methodology can be useful for predicting responses to climate and land cover changes that are anticipated for the southwestern United States.
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!
Hydrology Seminar – Dr Jessica Lundquist, 10th April
Dr Jessica Lundquist, Associate Professor at the University of Washington, will speak on Cold Air Pools in Complex Terrain, on Tuesday April 10th at 2pm in Agri 2C71.
In complex terrain, air in contact with the ground becomes cooled from radiative energy loss on a calm clear night and, being denser than the free atmosphere at the same elevation, sinks to valley bottoms. Cold-air pooling (CAP) occurs where this cooled air collects on the landscape. We present an objective mapping algorithm for identifying cold-air pool locations and compare the results against distributed temperature measurements in Loch Vale, Rocky Mountain National Park, Colorado; in the Eastern Pyrenees, France; and in Yosemite National Park, Sierra Nevada, California. We then discuss the impacts of cold air pools on snow, hydrology, and ecology, both in the present day and under a changing climate.
‘Why Cold Matters’ in Canmore Press
This week’s edition of Canmore’s Rocky Mountain Outlook carried a detailed report on Why Cold Matters: The State and Fate of Canada’s Ice and Snow, an evening of presentations co-hosted by the Centre for Hydrology and the Interpretive Guides’ Association on Thursday, March 1.
Presenters included Prof John Pomeroy (Director of the Centre for Hydrology), Bob Sandford (CH associate and chair of the Canadian arm of the UN’s Water for Life Decade), and glaciologist Dr Shawn Marshall (University of Calgary): all three are key members of the Western Watersheds Research Collaborative.
Their talks provided illustrations of entire ecosystems which have evolved in alpine and glacial habitats, and of the immense importance of snow and ice as store-houses of water for human use. With changes to global climate likely to lead to temperature increases of as much as 4° C in the next few decades, their continued existence is looking increasingly precarious.
The article is available on the Outlook’s web-site.
Pomeroy / Shook SWA Flood Report in the News
CBC News has posted a report about a recent review of operations at Lake Diefenbaker preceding and during the floods of late Spring 2011, conducted by U of S hydrologists Prof John Pomeroy and Dr Kevin Shook: the article is available on the CBC Website.
The Winnipeg Free Press also published its perspective on the report.
The study, conducted on behalf of the Saskatchewan Watershed Authority, highlights the challenges of striking the right balance when trading-off the competing demands of flood protection, electricty generation and water supply. It notes that minimum water levels in the lake have been rising over the years, and that inflows from snowmelt and rainfall were – despite the best efforts of SWA staff – under-predicted, due in part to a paucity of gauges in the watersheds which drain into the lake.
The report is available as a PDF from the SWA website at the following URL.
Why Cold Matters: The State and Fate of Canadas Ice and Snow – 1st March 2012
The Centre for Hydrology is co-sponsoring a suite of presentations hosted by the Interpretive Guides’ Association on Thursday, March 1 at the Policeman’s Creek Drop-In Centre in Canmore, AB, entitled Why Cold Matters: The State and Fate of Canada’s Ice and Snow.
The evening will feature presentations by Prof John Pomeroy (Director of the Centre for Hydrology), Bob Sandford (CH associate and chair of the Canadian arm of the UN’s Water for Life Decade), and glaciologist Dr Shawn Marshall (University of Calgary): all three presenters are key members of the Western Watersheds Research Collaborative.
“Canadians love their snow and its beauty, but often see it as something to be only shovelled or skied upon,” says Dr Pomeroy. “But, not only is it one of the most beautiful and physically complex natural phenomena, it is the home of many plants and animals, the food source for many more and the provider of water for the alpine summer and for the rivers that drain the mountains to provide water to the parched prairies.”
The role of snow as a part of the mountain ecosystem, how it interacts with forests and alpine vegetation and how it is sensitive to climate warming comprise just part of the focus of the presentation.
Summarizing the recent findings of two networks of cold regions research funded by the Canadian Foundation for Climate & Atmospheric Science that form the basis of his forthcoming book, Cold Matters: The State and Fate of Canada’s Fresh Water, Mr Sandford will focus on how seemingly small changes in temperature are influencing not just Canada’s climate, but also Canadians’ very identity.
“We are likely the first generation of human beings to accurately measure and fully understand how what we may have once thought were very small relative changes in mean temperature – changes as small as a single degree Celcius – can result in changes in the behaviour of the atmosphere noticeable enough to be reflected in the patterns of the seasons,” Sandford said.
“Because the most pronounced warming is occurring in winter, the most visibly obvious changes are related to the extent and duration of snow pack and snow cover. Snow cover, atmospheric circulation and temperature are inter-dependent and relate to one another as feedbacks. Water and temperature define climate. Climate defines ecosystems; and ecosystems define us.”
“In the absence of snow we would be different people living in a different world. It appears that, in the context of where and how we live in Canada, cold really does matter.”
Dr Marshall will discuss the latest research findings related to the effects of contemporary climatic trends on the extent and influence of glaciers in Canada’s western mountains and abroad, while Pomeroy will share the findings of his own research.
“The water security of Western Canada is predicated on the preservation of the natural flows and storage of mountain snow, ice and water,” Pomeroy said. “This controls our natural ecosystems and our ability to provide communities, food and energy throughout Western Canada. We risk everything by losing it, and so must conserve our mountain cold environments.”
Why Cold Matters: The State and Fate of Canada’s Ice and Snow takes place on Thursday, March 1 at the Policeman’s Creek Drop-In Centre. Doors open at 7 with the presentation beginning at 7:30. Admission is free.