Professor Bob Patrick of the Centre for Hydrology is serving as guest editor of the journal, Water, on this special issue relating to the water resources management and water security problems of small island communities. Those with research results on this topic are encourage to contact Dr. Patrick (robert.patrick@usask.ca).
Click here to see more details on the issue, including messages from Dr. Patrick and Editor-in-Chief Dr. Jean-Luc Probst.
Robert Sandford
Inter Press Service News Agency
May18, 2021
The year 2020 will forever be notorious for the COVID-19 pandemic but it might also be known by historians for a precipitous rise in second order climate change consequences — a new elephant in the room.
Familiar first order consequences, as documented in the World Meteorological Organization’s most recent State of the Global Climate report in April (at https://bit.ly/3eyrPwU), were the ongoing temperature rise over land and sea, melting sea ice and glaciers, higher sea levels, and changes in precipitation patterns.
Also in 2020, continuing a decade-long trend: widespread drought, heat waves, wildfires, cyclones, and flooding, especially in Africa and Asia but also in South America and the United States.
All these led to the second order consequences: Greater food insecurity and an accelerated explosion in involuntary human migration and displacement worldwide.
Read the article here: Climate Crisis: Elephants in the Room are Getting Nastier | Inter Press Service (ipsnews.net)
The spatial extent of hydrological and landscape changes across the mountains and prairies of Canada in the Mackenzie and Nelson River basins based on data from a warm-season time window
Paul H. Whitfield, Philip D. A. Kraaijenbrink, Kevin R. Shook, and John W. Pomeroy
Hydrology and Earth System Sciences, Volume 25, Issue 5
May18, 2021
DOI: https://doi.org/10.5194/hess-25-2513-2021
Abstract
East of the Continental Divide in the cold interior of Western Canada, the Mackenzie and Nelson River basins have some of the world’s most extreme and variable climates, and the warming climate is changing the landscape, vegetation, cryosphere, and hydrology. Available data consist of streamflow records from a large number (395) of natural (unmanaged) gauged basins, where flow may be perennial or temporary, collected either year-round or during only the warm season, for a different series of years between 1910 and 2012. An annual warm-season time window where observations were available across all stations was used to classify (1) streamflow regime and (2) seasonal trend patterns. Streamflow trends were compared to changes in satellite Normalized Difference Indices.
Clustering using dynamic time warping, which overcomes differences in streamflow timing due to latitude or elevation, identified 12 regime types. Streamflow regime types exhibit a strong connection to location; there is a strong distinction between mountains and plains and associated with ecozones. Clustering of seasonal trends resulted in six trend patterns that also follow a distinct spatial organization. The trend patterns include one with decreasing streamflow, four with different patterns of increasing streamflow, and one without structure. The spatial patterns of trends in mean, minimum, and maximum of Normalized Difference Indices of water and snow (NDWI and NDSI) were similar to each other but different from Normalized Difference Index of vegetation (NDVI) trends. Regime types, trend patterns, and satellite indices trends each showed spatially coherent patterns separating the Canadian Rockies and other mountain ranges in the west from the poorly defined drainage basins in the east and north. Three specific areas of change were identified: (i) in the mountains and cold taiga-covered subarctic, streamflow and greenness were increasing while wetness and snowcover were decreasing, (ii) in the forested Boreal Plains, particularly in the mountainous west, streamflows and greenness were decreasing but wetness and snowcover were not changing, and (iii) in the semi-arid to sub-humid agricultural Prairies, three patterns of increasing streamflow and an increase in the wetness index were observed. The largest changes in streamflow occurred in the eastern Canadian Prairies.
Read the full publication here.
Lindsey E. Langs, Richard M. Petrone, John W. Pomeroy
Hydrological Processes, Volume 35, Issue 5
April 2, 2021
DOI: https://doi.org/10.1002/hyp.14158
Abstract
Hydrological processes in mountain headwater basins are changing as climate and vegetation change. Interactions between hydrological processes and subalpine forest ecological function are important to mountain water supplies due to their control on evapotranspiration (ET). Improved understanding of the sensitivity of these interactions to seasonal and interannual changes in snowmelt and summer rainfall is needed as these interactions can impact forest growth, succession, health, and susceptibility to wildfire. To better understand this sensitivity, this research examined ET for a sub-alpine forest in the Canadian Rockies over two contrasting growing seasons and quantified the contribution of transpiration (T) from the younger tree population to overall stand ET. The younger population was focused on to permit examination of trees that have grown under the effect of recent climate change and will contribute to treeline migration, and subalpine forest densification and succession. Research sites were located at Fortress Mountain Research Basin, Kananaskis, Alberta, where the subalpine forest examined is composed of Abies lasiocarpa (Subalpine fir) and Picea engelmannii (Engelmann spruce). Seasonal changes in water availability from snowmelt, precipitation, soil moisture reserves yielded stark differences in T and ET between 2016 and 2017. ET was higher in the drier year (2017), which had late snowmelt and lower summer rainfall than in the wetter year (2016) that had lower snowmelt and a rainy summer, highlighting the importance of spring snowmelt recharge of soil moisture. However, stand T of the younger trees (73% of forest population) was greater (64 mm) in 2016 (275 mm summer rainfall) than 2017 (39 mm T, 147 mm summer rainfall), and appears to be sensitive to soil moisture decreases in fall, which are largely a function of summer period rainfall. Relationships between subalpine forest water use and different growing season and antecedent (snowmelt period) hydrological conditions clarify the interactions between forest water use and alpine hydrology, which can lead to better anticipation of the hydrological response of subalpine forest-dominated basins to climate variability and change.
Read the full article here.
Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 2: Future change in cryosphere, vegetation, and hydrology
DeBeer, C. M., Wheater, H. S., Pomeroy, J. W., Barr, A. G., Baltzer, J. L., Johnstone, J. F., Turetsky, M. R., Stewart, R. E., Hayashi, M., van der Kamp, G., Marshall, S., Campbell, E., Marsh, P., Carey, S. K., Quinton, W. L., Li, Y., Razavi, S., Berg, A., McDonnell, J. J., Spence, C., Helgason, W. D., Ireson, A. M., Black, T. A., Elshamy, M., Yassin, F., Davison, B., Howard, A., Thériault, J. M., Shook, K., Demuth, M. N., and Pietroniro, A.
Hydrology and Earth System Sciences, Volume 25, Issue 4
April 9, 2021
DOI: https://doi.org/10.5194/hess-25-1849-2021
This article examines future changes in land cover and hydrological cycling across the interior of western Canada under climate conditions projected for the 21st century. Key insights into the mechanisms and interactions of Earth system and hydrological process responses are presented, and this understanding is used together with model application to provide a synthesis of future change. This has allowed more scientifically-informed projections than have hitherto been available.
Abstract:
The interior of western Canada, like many similar cold mid- to high-latitude regions worldwide, is undergoing extensive and rapid climate and environmental change, which may accelerate in the coming decades. Understanding and predicting changes in coupled climate–land–hydrological systems are crucial to society yet limited by lack of understanding of changes in cold-region process responses and interactions, along with their representation in most current-generation land-surface and hydrological models. It is essential to consider the underlying processes and base predictive models on the proper physics, especially under conditions of non-stationarity where the past is no longer a reliable guide to the future and system trajectories can be unexpected. These challenges were forefront in the recently completed Changing Cold Regions Network (CCRN), which assembled and focused a wide range of multi-disciplinary expertise to improve the understanding, diagnosis, and prediction of change over the cold interior of western Canada. CCRN advanced knowledge of fundamental cold-region ecological and hydrological processes through observation and experimentation across a network of highly instrumented research basins and other sites. Significant efforts were made to improve the functionality and process representation, based on this improved understanding, within the fine-scale Cold Regions Hydrological Modelling (CRHM) platform and the large-scale Modélisation Environmentale Communautaire (MEC) – Surface and Hydrology (MESH) model. These models were, and continue to be, applied under past and projected future climates and under current and expected future land and vegetation cover configurations to diagnose historical change and predict possible future hydrological responses. This second of two articles synthesizes the nature and understanding of cold-region processes and Earth system responses to future climate, as advanced by CCRN. These include changing precipitation and moisture feedbacks to the atmosphere; altered snow regimes, changing balance of snowfall and rainfall, and glacier loss; vegetation responses to climate and the loss of ecosystem resilience to wildfire and disturbance; thawing permafrost and its influence on landscapes and hydrology; groundwater storage and cycling and its connections to surface water; and stream and river discharge as influenced by the various drivers of hydrological change. Collective insights, expert elicitation, and model application are used to provide a synthesis of this change over the CCRN region for the late 21st century.
Read the full article here.
Meteorological observations collected during the Storms and Precipitation Across the continental Divide Experiment (SPADE), April–June 2019
J.M. Thériault, S.J. Déry, J.W. Pomeroy, H.M. Smith, J. Almonte, A. Bertoncini, R.W. Crawford, A. Desroches-Lapointe, M. Lachapelle, Z. Mariani, S. Mitchell, J.E. Morris, C. Hébert-Pinard, P. Rodriguez, and H.D. Thompson
Earth System Science Data, Volume 13, Issue 3
March 24, 2021
https://doi.org/10.5194/essd-13-1233-2021
Abstract:
The continental divide along the spine of the Canadian Rockies in southwestern Canada is a critical headwater region for hydrological drainages to the Pacific, Arctic, and Atlantic oceans. Major flooding events are typically attributed to heavy precipitation on its eastern side due to upslope (easterly) flows. Precipitation can also occur on the western side of the divide when moisture originating from the Pacific Ocean encounters the west-facing slopes of the Canadian Rockies. Often, storms propagating across the divide result in significant precipitation on both sides. Meteorological data over this critical region are sparse, with few stations located at high elevations. Given the importance of all these types of events, the Storms and Precipitation Across the continental Divide Experiment (SPADE) was initiated to enhance our knowledge of the atmospheric processes leading to storms and precipitation on either side of the continental divide. This was accomplished by installing specialized meteorological instrumentation on both sides of the continental divide and carrying out manual observations during an intensive field campaign from 24 April–26 June 2019. On the eastern side, there were two field sites: (i) at Fortress Mountain Powerline (2076 m a.s.l.) and (ii) at Fortress Junction Service, located in a high-elevation valley (1580 m a.s.l.). On the western side, Nipika Mountain Resort, also located in a valley (1087 m a.s.l.), was chosen as a field site. Various meteorological instruments were deployed including two Doppler light detection and ranging instruments (lidars), three vertically pointing micro rain radars, and three optical disdrometers. The three main sites were nearly identically instrumented, and observers were on site at Fortress Mountain Powerline and Nipika Mountain Resort during precipitation events to take manual observations of precipitation type and microphotographs of solid particles. The objective of the field campaign was to gather high-temporal-frequency meteorological data and to compare the different conditions on either side of the divide to study the precipitation processes that can lead to catastrophic flooding in the region. Details on field sites, instrumentation used, and collection methods are discussed. Data from the study are publicly accessible from the Federated Research Data Repository at https://doi.org/10.20383/101.0221 (Thériault et al., 2020). This dataset will be used to study atmospheric conditions associated with precipitation events documented simultaneously on either side of a continental divide. This paper also provides a sample of the data gathered during a precipitation event.
Read more here.
Li Xu, Feng Mao, James S. Famiglietti, John W. Pomeroy, Claudia Pahl-Wostl
Multisystemic Resilience: Adaptation and Transformation in Contexts of Change
March, 2021
DOI: 10.1093/oso/9780190095888.001.0001
Abstract:
People and water interact over time and across space as coupled systems. Investigating the resilience of such coupling should take a multisystemic approach to address not only the resilience in different human and water systems, but also the interrelationship between their resilience processes. Based on the three framings of resilience in the coupled human–water context (i.e., social resilience, hydrological resilience, and socio-hydrological resilience), a conceptual framework is proposed for understanding the cascading effects of resilience along a chain of resilience change across systems and scales. The authors use a case example from a drainage basin in the Canadian Prairies to exemplify this framework and demonstrate how a change in the resilience of one system can exert an impact on the resilience of another, in socio-hydrological systems that are under the influence of both human activities and climate change.
Read the full article here.
Conway, J.P., Helgason, W.D., Pomeroy, J.W., Sicart, J.E.
Journal of Geophysical Research – Atmospheres, Volume 126, Issue 6
February 13, 2021
DOI: https://doi.org/10.1029/2020JD034225
Abstract
Atmospheric boundary layer (ABL) dynamics over glaciers mediate the response of glacier mass balance to large‐scale climate forcing. Despite this, very few ABL observations are available over mountain glaciers in complex terrain. An intensive field campaign was conducted in June 2015 at the Athabasca Glacier outlet of Columbia Icefield in the Canadian Rockies. Observations of wind and temperature profiles with novel kite and radio‐acoustic sounding systems showed a well‐defined mesoscale circulation developed between the glacier and snow‐free valley in fair weather. The typical vertical ABL structure above the glacier differed from that expected for “glacier winds”; strong daytime down‐glacier winds extended through the lowest 200 m with no up‐valley return flow aloft. This structure suggests external forcing at mesoscale scales or greater and is provisionally termed an “icefield breeze.” A wind speed maximum near the surface, characteristic of a “glacier wind,” was only observed during night‐time and one afternoon. Lapse rates of air temperature down the glacier centerline show the interaction of down‐glacier cooling driven by sensible heat loss into the ice, entrainment and periodic disruption and warming. Down‐glacier cooling was weaker in “icefield breeze” conditions, while in “glacier wind” conditions, stronger down‐glacier cooling enabled large increases in near‐surface temperature on the lower glacier during periods of surface boundary layer (SBL) disruption. These results raise several questions, including the impact of Columbia Icefield on the ABL and melt of Athabasca Glacier. Future work should use these observations as a testbed for modeling spatio‐temporal variations in the ABL and SBL within complex glaciated terrain.
Read the full article here.
Peiris: Saskatchewan wetlands at critical point, protection policy needed
Sarath Peiris
The Star Phoenix
February 18, 2021
It’s astounding that Saskatchewan still doesn’t have a comprehensive policy to manage and preserve its wetlands, which have been steadily drained since the early 1900s to accommodate agriculture. More than 50 per cent of these invaluable sites have now disappeared while the rest are under threat.
With half of Canada’s arable land, Saskatchewan should be the leader in acting to preserve wetlands that provide a wide array of environmental services such as serving as wildlife habitats and carbon sinks, producing pollinators, recharging aquifers, purifying water, retaining nutrients, mitigating flooding, contributing to soil health, and providing water security in a drought-prone province.
Read the full article here.
Multi-scale snowdrift-permitting modelling of mountain snowpack
Vincent Vionnet, Christopher B. Marsh, Brian Menounos, Simon Gascoin, Nicholas E. Wayand, Joseph Shea, Kriti Mukherjee, and John W. Pomeroy
The Cryosphere, Volume 15, Issue 2
February 17, 2021
DOI: https://doi.org/10.5194/tc-15-743-2021
Abstract
The interaction of mountain terrain with meteorological processes causes substantial temporal and spatial variability in snow accumulation and ablation. Processes impacted by complex terrain include large-scale orographic enhancement of snowfall, small-scale processes such as gravitational and wind-induced transport of snow, and variability in the radiative balance such as through terrain shadowing. In this study, a multi-scale modelling approach is proposed to simulate the temporal and spatial evolution of high-mountain snowpacks. The multi-scale approach combines atmospheric data from a numerical weather prediction system at the kilometre scale with process-based downscaling techniques to drive the Canadian Hydrological Model (CHM) at spatial resolutions allowing for explicit snow redistribution modelling. CHM permits a variable spatial resolution by using the efficient terrain representation by unstructured triangular meshes. The model simulates processes such as radiation shadowing and irradiance to slopes, blowing-snow transport (saltation and suspension) and sublimation, avalanching, forest canopy interception and sublimation, and snowpack melt. Short-term, kilometre-scale atmospheric forecasts from Environment and Climate Change Canada’s Global Environmental Multiscale Model through its High Resolution Deterministic Prediction System (HRDPS) drive CHM and are downscaled to the unstructured mesh scale. In particular, a new wind-downscaling strategy uses pre-computed wind fields from a mass-conserving wind model at 50 m resolution to perturb the mesoscale HRDPS wind and to account for the influence of topographic features on wind direction and speed. HRDPS-CHM was applied to simulate snow conditions down to 50 m resolution during winter 2017/2018 in a domain around the Kananaskis Valley (∼1000 km2) in the Canadian Rockies. Simulations were evaluated using high-resolution airborne light detection and ranging (lidar) snow depth data and snow persistence indexes derived from remotely sensed imagery. Results included model falsifications and showed that both wind-induced and gravitational snow redistribution need to be simulated to capture the snowpack variability and the evolution of snow depth and persistence with elevation across the region. Accumulation of windblown snow on leeward slopes and associated snow cover persistence were underestimated in a CHM simulation driven by wind fields that did not capture lee-side flow recirculation and associated wind speed decreases. A terrain-based metric helped to identify these lee-side areas and improved the wind field and the associated snow redistribution. An overestimation of snow redistribution from windward to leeward slopes and subsequent avalanching was still found. The results of this study highlight the need for further improvements of snowdrift-permitting models for large-scale applications, in particular the representation of subgrid topographic effects on snow transport.
Read the full article here.