Hydrology Seminar – Wednesday December 19th, 12:00noon

Dr Jean-Emmanuel Sicart, Researcher at the IRD, University of Grenoble, will present a seminar on
The Analysis of seasonal variations in energy fluxes and meltwater discharge of a Tropical high-altitude Glacier
On Wednesday 19th December, 2012, at 12noon in Room 146 of Kirk Hall.
The seminar will present a study of the atmospheric forcing that controls seasonal variations in the mass balance and in meltwater discharge of the tropical glacier Zongo, Bolivia (16°S, 6000-4900 m asl. 2.4 km²). The full abstract is available here.
This is a ‘brown bag lunch’ event, so please feel free to bring your lunch, and to pass this information on to others who might be interested.

Dr Cherie Westbrook’s research featured in Canadian Geographic Magazine

Associate Professor Cherie Westbrook of the Centre for Hydrology and Dept of Geography & Planning and her wetland ecohydrology research team’s results were featured in this month’s Canadian Geographic article on Rethinking the Beaver.
In the article, Dr Westbrook explains the ecohydrological approach to study of hydrology where beaver are present, and the tremendous impact beaver dams have in enhancing groundwater recharge. She also notes the impact of beaver-enhanced surface and groundwater storage in headwater streams on reducing the variability of streamflow, including maintaining low flows in drought situations. More information on Dr Westbrook’s research can be found here.

CH Marmot Creek Workshop – 21-22 February 2013

The Centre for Hydrology is organising a workshop to mark 50 years of academic activity at its Marmot Creek Research Basin, to be held from 21-22 February 2013 at the Coldwater Centre, Barrier Lake Biogeoscience Institute, near Kananaskis, Alberta.
This meeting will
– Celebrate the half-century of work at the Basin
– Review the challenges, designs and results of over this time, and
– Plan future scientific activities
Talks and posters are solicited on a range of topics: the abstract submission deadline is 15 January 2013.
More information is available here

CH Water Policy Expert on CBC

CBC News reported on a tour of the Columbia Icefields in the Canadian Rockies, led by Bob Sandford (EPCOR Chair for the Canadian Partnership Initiative of the United Nations Water for Life Decade and long-standing contributor to the Centre for Hydrology), on Wednesday 17 October 2012, as part of a conference titled Storm Warning – Water, Energy and Climate Security in a Changing World in Banff, Alberta.
His aim was to offer the group of leading water and climate scientists, engineers, risk managers, municipal planners and policy experts an opportunity to “see first-hand why we’re concerned about warming effects on the hydrological cycle”, as a result of climate change.
More detail about the field-trip and Sandford’s comments is available on the CBC website.

CH Director on Global Saskatoon

During an interview by Global Saskatoon, CH Director Prof. John Pomeroy talked about the likelihood of greater likelihood of rain and tornadoes, and of milder winters, as a result of a changing climate. He commented on the running in recent years of the Jet Stream at much higher latitudes than ever observed previously, which helps to pull moist, warm air north into the Prairies from the Gulf of Mexico. One principal problem with this is that Saskatchewan’s infrastructure has been built to cope with generally drier and colder conditions, and this poses challenges for the future.
Details of the interview are available on the Global web-site

Hydrology Seminar – Wednesday October 3rd, 11:30am

Dr Keith Musselman, Postdoctoral Research Associate at the Centre for Hydrology, will present a seminar entitled
Inter-annual snow accumulation and melt patterns in forested and alpine terrain;
a case study from the Sierra Nevada, California

On Wednesday October 3rd, 2012, at 11:30am, in AGRI 1E85
Results are presented from a study of snowpack dynamics in the southern Sierra Nevada, California. The study area covers 1800 km2 and a 3600 m elevation gradient. The accuracy of a distributed snow model is evaluated against a multi-scale suite of field measurements including a network of snow depth sensors, basin-scale manual surveys, and airborne LiDAR. In general, the model accurately simulated the seasonal maximum snow depth and SWE at lower and middle elevations. The model overestimated SWE at upper elevations where wind effects are pronounced and no precipitation measurements were available. The SWE errors were partially explained (R2 > 0.80, p<0.01) by the distance of the SWE measurement from the nearest precipitation gauge. The results suggest that precipitation uncertainty and wind redistribution are both critical limitations on snow model accuracy, particularly at upper elevations. Analyses of snowmelt patterns highlight distinct differences in melt dynamics at lower, middle, and upper elevations. Specifically, forested middle elevations experienced the most sustained snowmelt at relatively low seasonal average melt rates (~ 5 mm day-1). This unique melt timing and rate may be critical to the local forest ecosystem. Furthermore, the three years evaluated in this study indicate a marked sensitivity of this elevation range to seasonal meteorology, suggesting that it could be highly sensitive to future changes in climate.

CH / CSHS Kananaskis short course, March 2013

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’!

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