Browsing by Author "Shook, Kevin"
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Item 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, JaredIn 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.Item Climate Change in Canadian Floodplain Mapping Assessments(Centre for Hydrology, University of Saskatchewan, Saskatoon, Saskatchewan, 2020) Rajulapati, Chandra Rupa; Tesemma, Zelalem; Shook, Kevin; Papalexiou, Simon Michael; Pomeroy, John W.In the recent decades, precipitation patterns and corresponding streamflow responses in many cold regions catchments have changed considerably due to warming. Understanding historical changes and predicting future responses are of great importance for planning and management of water resources systems. Regional climate simulations using convention- permitting models are helpful in representing the fine-scale cloud and mesoscale processes, which are critical for understanding the physical mechanisms that cause in convective precipitation. From a hydrological perspective, these fine resolution simulations are helpful in understanding the runoff generation mechanisms, particularly for mountainous watersheds, which have high spatial variation in precipitation due to large differences in elevation over small distances. The sister-study of this report, the Bow River Basin Study (BRBS), used a physically based hydrological land surface scheme along with a water management model, coupled with a high resolution convention- permitting atmospheric regional model (Weather Research and Forecasting, WRF) to understand the streamflow generating mechanisms and identify the changes in streamflow responses of the Bow and Elbow River Basins. The coupled model appears to provide a large improvement in predictability, with minimal calibration of parameters and without bias correction of forcing from the atmospheric model. The model4 was able to provide reliable estimates of streamflows, despite the complex topography in the catchment. Using the WRF Pseudo Global Warming (PGW) scenario, estimated future streamflows simulated were then used to develop projected flow exceedance curves. The uncertainty in the simulations is extremely helpful in the risk assessment for downstream flood inundations. However, the uncertainty in streamflows cannot be assessed as the WRF- PGW dataset was only available for a single realization, because of the high computational cost. The research presented in this report focusses instead on using the highly efficient hydrological model developed and verified in BRBS whilst assessing uncertainty using another regional climate model, the CanRCM4, where many realizations are available for different boundary conditions. Since the CanRCM4 simulations have a relatively low resolution, a novel methodology was developed to adjust regional climate model outputs using the WRF-PGW data. An ensemble of 15 CanRCM4 simulations was used to force the Bow River basin model to determine a measure of the uncertainty in the simulated streamflows, and the projected streamflow exceedance probability curves. These curves are extremely useful for risk assessment for downstream flood inundations. Given the importance of understanding how much extreme precipitation will change in urban areas of the basin, where short duration high intensity events cause flash flooding, frequency analysis of these events was carried out for Calgary and Intensity Duration Frequency (IDF) curves were developed. A ready-to-use empirical form of IDF curve has been proposed from this analysis for the City of Calgary. The results from the WRF-PGW modelling indicated that future high flow, low frequency (exceedances less than 10%) streamflow events will decrease compared to those under the current climate condition by 4, 9 and 1.6 m3/s for the Bow River at Banff and Calgary and Elbow River at Sarcee Bridge respectively. The average of the 15 new CanRCM4-WRF-PGW results supports the above result with some greater decreases in streamflow of 9, 16 and 4 m3/s for Bow River at Banff and Calgary and Elbow River at Sarcee Bridge respectively. However, there were some CanRCM4-WRF-PGW realisations that suggested substantial increases in future low frequency streamflow from those indicated by the average CanRCM4- WRF-PGW-drive MESH model. The below average, high frequency (exceedances greater than 30%) future streamflows will increase modestly in all gauging locations by from 1 to 12.5 m3/s. The results of the extreme precipitation analysis at Calgary indicated an increase in future extreme precipitation events of all duration and return periods. On an average an increase of 1.5 times is noted for short return periods (=2, 5), and an increase of 4 times for long return periods (=500, 1000).Item Development of a Snowmelt Runoff Model for the Lower Smoky River(Centre for Hydrology, University of Saskatchewan, Saskatoon, Saskatchewan, 2013) Pomeroy, John W.; Shook, Kevin; Fang, Xing; Brown, Tom; Marsh, ChristopherThe Smoky River tributary of the Peace River has an ungauged (in real-time) basin area of 23,769 km2, corresponding to 46% of its basin area of 51,839 km2 . The purpose of this study was to develop a model to simulate the daily spring ungauged flows of the Smoky River and its main tributary, the Little Smoky River for recent periods using measured meteorological data and forecast periods using the outputs of a numerical weather forecast model. A physically-based model of the ungauged local flows contributing to the Smoky River at Watino and the Little Smoky River at Guy, the Lower Smoky River Model (LSRM), was developed using the CRHM platform. The model was deployed to 26 ungauged sub-basins, from which discharges were routed and accumulated to produce the ungauged discharges at Guy and Watino. The LSRM modelled discharge was evaluated to estimate the discharge of the Smoky River and Little Smoky River in an operational setting with measured meteorological observations. Results from this comparison were very good with a high degree of hydrograph predictability, small bias in flow estimation, and very good prediction of peak daily discharge and excellent prediction of the timing of peak daily discharge. The results were somewhat better for the Smoky River than for the Little Smoky River, showing the effect of increasing basin size in compensating for inadequate precipitation observation density and/or errors in model structure or parameterization. The model has not yet been tested in an operational setting during a spring snowmelt event and its full capabilities and usefulness cannot be assessed until it has been tested in such a setting.Item Diagnosis of Historical and Future Flow Regimes of the Bow River at Calgary Using a Dynamically Downscaled Climate Model and a Physically Based Land Surface Hydrological Model : Final Report(Centre for Hydrology, University of Saskatchewan, Saskatoon, Saskatchewan, 2020) Tesemma, Zelalem; Shook, Kevin; Princz, Daniel; Razavi, Saman; Davison, Bruce; Li, Yanping; Pietroniro, Alain; Pomeroy, John W.; wheater, howardThis report assesses the impacts of projected climate change on the hydrology, including the flood frequencies, of the Bow and Elbow Rivers above Calgary, Alberta. It reports on investigations of the effects of projected climate change on the runoff mechanisms for the Bow and Elbow River basins, which are important mountain headwaters in Alberta, Canada. The study developed a methodology and applied a case study for incorporating climate change into flood frequency estimates that can be applied to a variety of river basins across Canada.Item 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, ColinThis 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 EcozoneItem Sensitivity of extreme streamflow to wetland drainage and restoration in the Canadian Prairies(2023) He, Zhihua; Shook, Kevin; Spence, Christopher; Pomeroy, John; Whitfield, ColinItem 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, ChristopherExtensive 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.