Browsing Waterloo Research by Author "Shafii, Mahyar"
Now showing items 1-11 of 11
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Changes in Lake Phosphorus Loading and Cycling Accompanying the Transition from Agricultural to Urban Land Use in a Watershed of the Greater Toronto Area
Slowinski, Stephanie; Radosavljevic, Jovana; Graham, Alyssa; Ippolito, Isabella; Thomas, Kathryn Elizabeth; Rezanezhad, Fereidoun; Shafii, Mahyar; Parsons, Chris T.; Basu, Nandita B.; Wiklund, Johan Andre; Hall, Roland; Van Cappellen, Philippe (University of Waterloo, 2023-05-05)Agricultural intensification and urbanization alter biogeochemical cycling and substantially increase the export of nutrients, including phosphorus (P), to downstream lake ecosystems. Here, we reconstruct the post-1920 ... -
A diagnostic approach to constraining flow partitioning in hydrologic models using a multiobjective optimization framework
Shafii, Mahyar; Basu, Nandita; Craig, James R.; Schiff, Sherry L.; Van Cappellen, Philippe (American Geophysical Union, 2017-04-21)Hydrologic models are often tasked with replicating historical hydrographs but may do so without accurately reproducing the internal hydrological functioning of the watershed, including the flow partitioning, which is ... -
Effect of climate change and mining on hydrological connectivity of surficial layers in the Athabasca Oil Sands Region
Kompanizare, Mazda; Petrone, Richard M.; Shafii, Mahyar; Robinson, Derek T.; Rooney, Rebecca C. (Wiley, 2018-09-28)This research analyses the impact of climate change and surface mining activities on the hydrologic connectivity of surficial (soil and geological) layers located in a watershed in the Athabasca Oil Sands Region. Surface ... -
Improving the efficiency of Monte Carlo Bayesian calibration of hydrologic models via model pre-emption
Shafii, Mahyar; Tolson, Bryan A.; Matott, Loren Shawn (International Water Association, 2015-09-01)Bayesian inference via Markov Chain Monte Carlo (MCMC) sampling and sequential Monte Carlo (SMC) sampling are popular methods for uncertainty analysis in hydrological modelling. However, application of these methodologies ... -
Optimizing hydrological consistency by incorporating hydrological signatures into model calibration objectives
Shafii, Mahyar; Tolson, Bryan A. (American Geophysical Union, 2015-05-31)The simulated outcome of a calibrated hydrologic model should be hydrologically consistent with the measured response data. Hydrologic modelers typically calibrate models to optimize residual-based goodness-of-fit measures, ... -
A priori discretization error metrics for distributed hydrologic modeling applications
Liu, Hongli; Tolson, Bryan A.; Craig, James R.; Shafii, Mahyar (Elsevier, 2016-12-01)Watershed spatial discretization is an important step in developing a distributed hydrologic model. A key difficulty in the spatial discretization process is maintaining a balance between the aggregation-induced information ... -
Quantitative insights into phosphorus loadings and speciation in urban catchments
Shafii, Mahyar; Slowinski, Stephanie; Bhusal, Yubraj; Sabur, Md Abdus; Hitch, Calvin; Withers, William; Rezanezhad, Fereidoun; Van Cappellen, Philippe (University of Waterloo, 2023-05-16)Phosphorus (P) loadings in stormwater runoff drained from urban landscapes causes eutrophication in aquatic ecosystems downstream of urban areas. Many recent research have addressed urban P dynamics to improve understanding ... -
Salinization enhances eutrophication symptoms in a cold temperate urban lake
Radosavljevic, Jovana; Slowinski, Stephanie; Shafii, Mahyar; Rezanezhad, Fereidoun; Akbarzadeh, Zahra; Withers, William; Van Cappellen, Philippe (Elsevier, 2022-11-10)Salinization of inland freshwaters is observed around the world, but particularly in cold temperate regions due to the runoff of salt applied on roads as de-icing agents during the winter. This is the case for Lake Wilcox, ... -
Salinization increases eutrophication symptoms in freshwater urban lakes of North America
Radosavljevic, Jovana; Slowinski, Stephanie; Zhou, Bowen; Parsons, Chris T.; Rezanezhad, Fereidoun; Alcott, Lewis; Shafii, Mahyar; Van Cappellen, Philippe (University of Waterloo, 2023-05)The acceleration of global urbanization continues to fuel concerns surrounding water quality impairments in urban lakes, particularly their eutrophication. Eutrophication of freshwater environments is generally assumed to ... -
Uncertainty-based multi-criteria calibration of rainfall-runoff models: a comparative study
Shafii, Mahyar; Tolson, Bryan A.; Matott, Loren Shawn (Springer, 2014-08-01)This study compares formal Bayesian inference to the informal generalized likelihood uncertainty estimation (GLUE) approach for uncertainty-based calibration of rainfall-runoff models in a multi-criteria context. Bayesian ... -
URBAN PHOSPHORUS SPECIATION AND EXPORT LOADS: A PAIRED SEWERSHED FIELD AND MODELING STUDY
Kaykhosravi, Sarah; Slowinski, Stephanie; Bhusal, Yubraj; Shafii, Mahyar; Sabur, Md Abdus; Chomicki, Krista; Ruddy, Stephen; Rezanezhad, Fereidoun; Van Cappellen, Philippe (University of Waterloo, 2023-05-14)In this study, annual and seasonal loads of phosphorus (P) exported from two neighbouring urban sewersheds (AJE and AJW) discharging into Lake Ontario were estimated. The following different chemical pools of P were ...