HARVEST :: Browsing by Author "Whitfield, Colin"

Browsing by Author "Whitfield, Colin"

Now showing 1 - 8 of 8

An integrated assessment of impacts to ecosystem services associated with prairie pothole wetland drainage quantifying wide-ranging losses
(Canadian Science Publishing, 2024-06-20) Whitfield, Colin; Cavaliere, Emily; Baulch, Helen; Clark, Robert; Spence, Christopher; Shook, Kevin; He, Zhihua; Pomeroy, John W.; Wolfe, Jared
In many regions, a tradeoff exists between draining wetlands to support the expansion of agricultural land, and conserving wetlands to maintain their valuable ecosystem services. Decisions about wetland drainage are often made without identifying the impacts on the services these systems provide. We address this gap through a novel assessment of impacts on ecosystem services via wetland drainage in the Canadian prairie landscape. Draining pothole wetlands has large impacts, but sensitivity varies among the indicators considered. Loss of water storage increased the magnitude of median annual flows, but absolute increases with drainage were higher for larger, less frequent events. Total phosphorus exports increased in concert with streamflow. Our analysis suggested disproportionate riparian habitat losses with the first 30% of wetland area drained. Dabbling ducks and wetland-associated bird abundances respond strongly to the loss of small wetland ponds; abundances were predicted to decrease by half with the loss of only 20%–40% of wetland area. This approach to evaluating changes to key wetland ecosystem services in a large region where wetland drainage is ongoing can be used with an economic valuation of the drainage impacts, which should be weighed against the benefits associated with agricultural expansion.
Assessing runoff sensitivity of North American Prairie Pothole Region basins to wetland drainage using a basin classification-based virtual modelling approach
(Copernicus Publications on behalf of the European Geosciences Union, 2022) Spence, Christopher; He, Zhihua; Shook, Kevin R.; Pomeroy, John; Whitfield, Colin; Wolfe, Jared
Wetland drainage has been pervasive in the North American Prairie Pothole Region. There is strong evidence that this drainage increases the hydrological connectivity of previously isolated wetlands and, in turn, runoff response to snowmelt and rainfall. It can be hard to disentangle the role of climate from the influence of wetland drainage in observed records. In this study, a basin-classification-based virtual modelling approach is described that can isolate these effects on runoff regimes. The basin class which was examined, entitled Pothole Till, extends throughout much of Canada’s portion of the Prairie Pothole Region. Three knowledge gaps were addressed. First, it was determined that the spatial pattern in which wetlands are drained has little influence on how much the runoff regime was altered. Second, no threshold could be identified below which wetland drainage has no effect on the runoff regime, with drainage thresholds as low as 10 % in the area being evaluated. Third, wetter regions were less sensitive to drainage as they tend to be better hydrologically connected, even in the absence of drainage. Low flows were the least affected by drainage. Conversely, during extremely wet years, runoff depths could double as the result of complete wetland removal. Simulated median annual runoff depths were the most responsive, potentially tripling under typical conditions with high degrees of wet- land drainage. As storage capacity is removed from the landscape through wetland drainage, the size of the storage deficit of median years begins to decrease and to converge on those of the extreme wet years. Model simulations of flood frequency suggest that, because of these changes in antecedent conditions, precipitation that once could generate a median event with wetland drainage can generate what would have been a maximum event without wetland drainage. The advantage of the basin-classification-based virtual modelling approach employed here is that it simulated a long period that included a wide variety of precipitation and antecedent storage conditions across a diversity of wetland complexes. This has allowed seemingly disparate results of past research to be put into context and finds that conflicting results are often only because of differences in spatial scale and temporal scope of investigation. A conceptual framework is provided that shows, in general, how annual runoff in different climatic and drainage situations will likely respond to wetland drainage in the Prairie Pothole Region.
Development of the Prairie Hydrology Design and Analysis Product (PHyDAP)
(2023) Shook, Kevin; He, Zhihua; Spence, Christopher; Whitfield, Colin; Pomeroy, John
Currently, there are no tools which account for the complexities of prairie hydrology and hydrography available to hydrological practitioners for calculating return-period flows and flooding at small scales on the Canadian Prairies. The need for such tools is especially great due to non-stationarity from the effects of climate change and surface drainage. The Prairie Hydrology Design and Analysis Product (PHyDAP) uses the research results of the Global Water Futures Prairie Water Project to produce a spatial dataset which will allow practitioners to determine return-period flows and flooded areas in a scientifically defensible manner, while incorporating changes in the local climate and land use.
Modelling the regional sensitivity of snowmelt, soil moisture, and streamflow generation to climate over the Canadian Prairies using a basin classification approach
(Hydrology and Earth System Sciences, 10/9/2023) He, Zhihua; Shook, Kevin; Spence, Christopher; Pomeroy, John W.; Whitfield, Colin
This study evaluated the effects of climate perturbations on snowmelt, soil moisture, and streamflow generation in small Canadian Prairies basins using a modelling approach based on classification of basin biophysical characteristics. Seven basin classes that encompass the entirety of the Prairies Ecozone in Canada were determined by cluster analysis of these characteristics. Individual semi-distributed virtual basin (VB) models representing these classes were parameterized in the Cold Regions Hydrological Model (CRHM) platform, which includes modules for snowmelt and sublimation, soil freezing and thawing, actual evapotranspiration (ET), soil moisture dynamics, groundwater recharge, and depressional storage dynamics including fill and spill runoff generation and variable connected areas. Precipitation (P) and temperature (T) perturbation scenarios covering the range of climate model predictions for the 21st century were used to evaluate climate sensitivity of hydrological processes in individual land cover and basin types across the Prairies Ecozone. Results indicated that snow accumulation in wetlands had a greater sensitivity to P and T than that in croplands and grasslands in all basin types. Wetland soil moisture was also more sensitive to T than the cropland and grassland soil moisture. Jointly influenced by land cover distribution and local climate, basin-average snow accumulation was more sensitive to T in the drier and grassland-characterized basins than in the wetter basins dominated by cropland, whilst basin-average soil moisture was most sensitive to T and P perturbations in basins typified by pothole depressions and broad river valleys. Annual streamflow had the greatest sensitivities to T and P in the dry and poorly connected Interior Grasslands (See Fig. 1) basins but the smallest in the wet and well-connected Southern Manitoba basins. The ability of P to compensate for warming-induced reductions in snow accumulation and streamflow was much higher in the wetter and cropland-dominated basins than in the drier and grassland-characterized basins, whilst decreases in cropland soil moisture induced by the maximum expected warming of 6 ∘C could be fully offset by a P increase of 11 % in all basins. These results can be used to (1) identify locations which had the largest hydrological sensitivities to changing climate and (2) diagnose underlying processes responsible for hydrological responses to expected climate change. Variations of hydrological sensitivity in land cover and basin types suggest that different water management and adaptation methods are needed to address enhanced water stress due to expected climate change in different regions of the Prairies Ecozone
Prairie Wetland Drainage Infographic
(Global Water Futures: Prairie Water Project. University of Saskatchewan, 2022) Morrison, Alasdair; Whitfield, Colin; Spence, Christopher
Sensitivity of extreme streamflow to wetland drainage and restoration in the Canadian Prairies
(2023) He, Zhihua; Shook, Kevin; Spence, Christopher; Pomeroy, John; Whitfield, Colin
Summary of Research Progress May 2023: “Partnerships and tools for water resilient prairie communities”
(2023) Miranda, Lauren; Spence, Christopher; Whitfield, Colin
Synthesis of science: findings on Canadian Prairie wetland drainage
(Taylor and Francis Online, 2021) Baulch, Helen; Whitfield, Colin; Wolfe, Jared; Basu, Nandita; Bedard-Haughn, Angela; Belcher, Kenneth; Clark, Robert; Ferguson, Grant; Hayashi, Masaki; Ireson, Andrew; Lloyd-Smith, Patrick; Loring, Philip; Pomeroy, John; Shook, Kevin; Spence, Christopher
Extensive wetland drainage has occurred across the Canadian Prairies, and drainage activities are ongoing in many areas (Prairie Habitat Joint Venture 2014; Dahl 1990; Watmough and Schmoll 2007; Bartzen et al. 2010; Dahl 2014; Dumanski et al. 2015; Waz and Creed 2017). In 2017 the Global Water Futures program funded the Prairie Water project, with the broad goal of helping to foster improved water security in the region (Spence et al. 2018). Throughout the duration of this project, it has been clear that a diverse group of stakeholders (including river basin organizations, government agencies, and landowners) is seeking the same information — a synthesis of what is known and not known about the effects of wetland drainage. This synthesis of the state of the science on wetland drainage in the Canadian Prairies is aimed at assembling current knowledge based on western scientific methods to articulate what is known about the variability of drainage effects across the region. Traditional knowledge, which represents a different but complementary way of knowing the functioning of prairie watersheds (sometimes also termed catchments, or basins), and the processes driving change within them, is not discussed here. Instead, this synthesis is presented in the spirit of building such collaborations. It summarizes current western scientific knowledge on surface hydrology, groundwater interactions, nutrient export, biodiversity, carbon storage and greenhouse gas dynamics, and wetland conservation socioeconomics. The implications to water security now and in the future are also discussed.

Browsing by Author "Whitfield, Colin"

Results Per Page

Sort Options