Tricia Stadnyk

A groundwater separation study in boreal wetland terrain: The WATFLOOD hydrological model compared with stable isotope tracers

Monitoring of stable water isotopes (18O and 2H) in precipitation and surface waters in the Mackenzie River basin of northern Canada has created new opportunities for researchers to study the complex hydrology and hydroclimatology of this remote region [1]. A number of prior studies have used stable isotope data to investigate aspects of the hydrological regime of the wetland-dominated terrain near Fort Simpson, Northwest Territories, Canada [2, 3]. The present paper compares estimates of groundwater contributions to streamflow derived using the WATFLOOD distributed hydrological model, equipped with a new water isotope tracer module, with the results of conventional isotope hydrograph separation [4] for five wetland-dominated catchments along the lower Liard River. The comparison reveals highly promising agreement, verifying that the hydrological model is simulating groundwater flow contributions to total streamflow with reasonable fidelity, especially during the crucial snowmelt period. Sensitivity analysis of the WATFLOOD simulations also reveals intriguing features about runoff generation from channelized fens, which may contribute less to streamflow than previously thought.

Performance Evaluation of the Canadian Precipitation Analysis (CaPA)

AbstractThis paper presents an assessment of the operational system used by the Meteorological Service of Canada for producing near-real-time precipitation analyses over North America. The Canadian Precipitation Analysis (CaPA) system optimally combines available surface observations with numerical weather prediction (NWP) output in order to produce estimates of precipitation on a 15-km grid at each synoptic hour (0000, 0600, 1200, and 1800 UTC). The validation protocol used to assess the quality of the CaPA has demonstrated the usefulness of the system for producing reliable estimates of precipitation over Canada, even in areas with few or no weather stations. The CaPA is found to be better in autumn, spring, and winter than in summer. This is because of the difficulty in correctly producing convective precipitation in the NWP because of the low spatial resolution of the meteorological model. An investigation of the quality of the precipitation analyses in the 15 terrestrial ecozones of Canada indicates ...

Model Based Spatial Distribution of Oxygen-18 Isotopes in Precipitation Across Canada

Challenges inherent in mesoscale (large domain) hydrologic modelling of remote ungauged basins include validation of model results and quantification of uncertainty in the predictions. Isotope equipped hydrological models, such as isoWATFLOOD, have the ability to simulate both quantity and isotopic composition of streamflow and runoff generation processes providing more options for model validation, but first require information about isotopic composition of precipitation across the model domain. The stable water isotopic composition of precipitation (18OPPT) is available from stations sampling monthly composite precipitation, but the data are spatially and temporally discontinuous, particularly in northern areas of Canada. Here we use new data from the Canadian Network for Isotopes in Precipitation (CNIP) to create and evaluate a variety of empirical relationships to develop improved interpolations of the spatial distribution of 18OPPT across Canada. The goal of this research is to develop 18OPPT prediction models that can be incorporated directly within the isoWATFLOOD hydrological modelling framework to provide spatially variant 18OPPT patterns as forcing data for the iso-hydrological model. Comparison of model results has identified models capable of simulating annual 18OPPT distributions, but also identified seasons and areas where the geographical and climatological parameters included in this analysis were not able to simulate the measured distributions. Spring, summer and fall model results were satisfactory; however, winter model results were more variable, indicating increased complexity in the driving forces of 18OPPT patterns during this season. Overall, model results improve with the addition of time-variant climate parameters, this finding being especially significant during the winter. Improving the precipitation input fields within isotope-equipped hydrological models will provide a valuable tool for water use management within large, remote, and often ungauged Canadian rivers and will facilitate studies of both climate variability and surface hydrology in remote regions.

The 2011 flood event in the Assiniboine River Basin: causes, assessment and damages

In spring and summer of 2011, the Assiniboine River and its tributaries underwent a flood of unprecedented proportions. It was, by several measures, including the computed return period and duration of flooding, a more extreme event than the 1997 Red River “Flood of the Century,” and may have been the most severe flood experienced in the history of Canada. The 2011 flood was the largest recorded in the over 100 years that flow records have been kept on the Assiniboine River. As reported in the 2013 Manitoba 2011 Flood Review Task Force Report, antecedent conditions, winter snowpack and summer rains combined to produce one of the largest floods ever experienced in Manitoba. The spring of 2011 was preceded by a very wet fall in 2010 when precipitation averaged between 150 and 200% of normal over a wide area in Manitoba and Saskatchewan This produced extremely high regional antecedent moisture conditions whereby soil moisture levels were 100 to 250% of the long-term average. Added to this, the winter snowpack was relatively high, varying geographically in the range of 90 to 130% of normal snow water content and lower-than-normal winter temperatures, causing significant frost penetration. The combination of high soil moisture in the previous summer/fall and deep frost penetration reduced the soil’s ability to absorb spring meltwater and increased runoff volumes contributing to the magnitude of the spring peak. The severe winter was followed by a series of rainfall events that resulted in unprecedented rainfall volumes in the region throughout the months of May, June and July, when some areas received rainfall amounts that were 350% of normal and produced up to two additional flood peaks at some locations. Flooding on the Assiniboine River near Brandon lasted for 120 days. Large volumes of floodwater were diverted to Lake Manitoba due to the use of the Portage Diversion to mitigate flooding downstream of the City of Portage La Prairie. This large volume of inflow resulted in a wind-effect-eliminated Lake Manitoba level that peaked at 249.1 m in late July of 2011, which was close to 1 m higher than flood stage and almost 1.5 m higher than the top of the desirable range. Peak outflow from Lake Manitoba into the Fairford River was almost double historic maxima and resulted in Lake St. Martin levels that peaked in July of 2011 at 245.55 m, which was more than 0.6 m higher than the historic peak that occurred under natural conditions in 1955, and 1.4 m above flood stage. The damage estimate for this flood event has not been finalized but is likely in excess of CAD

Background to flood control measures in the Red and Assiniboine River Basins

1 billion. The majority of flood damages were incurred by communities and infrastructure along major tributaries like the Souris and Qu’Appelle Rivers, and the communities on Lake Manitoba and Lake St. Martin. The Lake St. Martin First Nations community was virtually destroyed, and as of 2014 some First Nations people from the communities along Lake St. Martin are still evacuated and waiting for their homes and communities to be rebuilt. Temporary flood control works were largely effective in preventing infrastructure damage to communities along the Assiniboine River, such as Brandon, although the agricultural damage and damage to individual properties were extensive.

Identification of geographical influences and flow regime characteristics using regional water isotope surveys in the lower Nelson River, Canada

The City of Winnipeg and southern Manitoba have a long history of flooding, with flood events being recorded soon after the region was settled in the early nineteenth century. A devastating flood on the Red River in 1950 resulted in some of the earliest benefit–cost analyses in Canada with respect to flooding, and justified the construction of major flood mitigation projects on the Red and Assiniboine Rivers in the 1960s and 1970s. These projects were primarily designed to reduce the risk to the City of Winnipeg. Other projects have been constructed outside of the Winnipeg area, which have reduced flood damages to towns, individual farmsteads and rural residences. The level of flood protection has been re-evaluated every time a new flood of record occurs, and this has resulted in significant upgrading of existing works and the addition of more communities with permanent flood protection. As a result of the flood protection system that has been developed in Manitoba over the last 60 years, the damage caused by floods has been significantly reduced over natural conditions. The purpose of this paper is to provide context to flooding in Manitoba with a consideration of how flooding, flood damage and the impact on citizens of Manitoba have been mitigated by permanent flood protection works.

Linking physiography and evaporation using the isotopic composition of river water in 16 Canadian boreal catchments

Results are reported from a 3-year monitoring initiative (2010–2013) of stable water isotopes (δ18O and δ2H) at over 50 hydrometric sites in the lower portion of the Nelson River Basin, a key freshwater–marine corridor in Canada with global significance. Data are collected from annual synoptic surveys and a time-series monitoring program. Water isotope signals exhibit significant long-term average (with reported standard deviation) differences between the upper Nelson River (–10.5‰ δ18O ± 0.18‰) and Burntwood River (i.e. Churchill Basin; –12.8‰ δ18O ± 0.4‰) regions which are attributed to the geographic extent and origin of the water. Upper Nelson River flow-isotope signals suggest a more temperate climate, and exhibit reverse seasonal cycling (i.e. ice-on isotope enrichment; ice-off isotope depletion) due to the connectivity with and influence of Lake Winnipeg. In contrast, the Burntwood River behaves like a snowmelt-dominated river heavily influenced by wetland storage and enrichment during ice-off periods, exhibiting isotopic signals negatively correlated with headwater river discharge. Flow-weighted δ18O and δ2H show decreased variability in both regions at extreme low- and high-flow regimes, indicating a tendency towards a single dominant end member: wetland release (low-flow regime) or snowmelt/rainfall (high-flow regime). Mid- to normal-flow regimes exhibit increased isotopic variability, as do small headwater catchments resulting from varied source water contributions, residence times, mixing patterns and the role of landscape-specific features. The Stable Water Isotope Monitoring Network (SWIMN) presented enables the closure of water-isotope mass balance modelling that will facilitate the understanding of changes to freshwater–marine linkages. Les résultats sont basés sur une étude d’échantillonnage de 3 ans (2010–2013) d’isotopes stables de l’eau (δ18O et δ2H) à plus de 50 stations hydrométriques dans la partie inférieure du bassin de la rivière Nelson, un corridor marin d’eau fraîche du Canada d’importance mondiale. Les données sont tirées d’études synoptiques annuelles et d’un programme de mesure de séries chronologiques. Les signaux relevés dans les isotopes de l’eau montrent des différences significatives dans les moyennes à long terme (avec écart-type) entre les régions du haut de la rivière Nelson (–10.5‰ δ18O ± 0.18‰) et de la rivière Burntwood (c.-à-d. le bassin de Churchill; –12.8‰ δ18O ± 0.4‰) et sont attribuées à l’étendue géographique et à l’origine de l’eau. Les signaux d’isotopes instables du haut de la rivière Nelson suggèrent un climat plus tempéré et démontrent un cycle saisonnier inversé (c.-à-d. que lorsque les eaux sont recouvertes de gel, il y a enrichissement et qu’autrement, il y tarissement) résultant de la connexité avec le lac Winnipeg et de l’influence de ce dernier. À l’opposé, la rivière Burntwood réagit comme une rivière dominée par la fonte des neiges et fortement influencée par le stockage des terres humides et l’enrichissement au cours des périodes où les eaux ne sont pas recouvertes de glace, présentant des signaux isotopiques négativement corrélés avec les eaux d’amont. Les niveaux de δ18O et δ2H pondérés par le débit de l’eau présentent une diminution de la variabilité dans les deux régions lorsque les débits sont extrêmement bas ou élevés, indiquant une tendance vers une source unique : provenant des terres humides (faible débit) ou de la fonte des neiges ou d’averses de pluie (débit élevé). Les débits moyen à normal présentent une augmentation de la variabilité isotopique – comme c’est le cas pour les petits bassins récepteurs d’eau d’amont formés de sources d’eau variées – du temps de rétention, de la composition des sources et du rôle des caractéristiques spécifiques au paysage terrestre. Le Réseau de contrôle des isotopes d’eau stable (SWIMN) présenté ici permet de préserver l’équilibre du bilan massique des isotopes d’eau, ce qui permettra de mieux comprendre les changements dans les liens entre les eaux douces et marines.

Impacts of 1.5 and 2.0 °C Warming on Pan‐Arctic River Discharge Into the Hudson Bay Complex Through 2070

170 Copyright

Ten Years of Science Based on the Canadian Precipitation Analysis: A CaPA System Overview and Literature Review†

Impacts of 1.5 and 2.0 degrees C Warming on Pan-Arctic River Discharge Into the Hudson Bay Complex Through 2070

Towards hydrological model calibration and validation: simulation of stable water isotopes using the isoWATFLOOD model

Abstract Near real-time quantitative precipitation estimates are required for many applications including weather forecasting, flood forecasting, crop management, forest fire prevention, hydropower production, and dam safety. Since April 2011, such a product has been available from Environment and Climate Change Canada for a domain covering all North America. This product, known as the Regional Deterministic Precipitation Analysis, is generated using the Canadian Precipitation Analysis (CaPA) system. Although it was designed for near real-time use, an archive of pre-operational and operational products going back to 2002 is now available and has been used in numerous studies. This paper presents a review of the various scientific publications that have reported either using or evaluating CaPA products. We find that the product is used with success both for scientific studies and operational applications and compares well with other precipitation datasets. We summarize the strengths and weaknesses of the system as reported in the literature. We also provide users with information on how the system works, how it has changed over time, and how the archived and near real-time analyses can be accessed and used. We finally briefly report on recent and upcoming improvements to the product based, in part, on the results of this literature review.