Canadian Watershed Information Network (CEOS)

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Open Access
1999 Lake Winnipeg project: cruise report and scientific results
(Government of Canada, Natural Resources Canada, 1999) Simpson, S.L; Thorleifson, L.H.; Lewis, C.F.M.; King, J.W.
Following the 1997 Red River flood, a program of research was initiated to determine how large the floods can be, how often large floods have occurred in recent centuries, and whether natural factors may be changing the flood risk. As part of this program, 15 cores were collected from the south basin of Lake Winnipeg. Paleomagnetic profiles were used to select three apparently undisturbed, high-sedimentation rate cores for detailed chemical, physical, and biological analyses, to assess whether Red River floods are recognizable in the lake. A thousand-year paleomagnetic chronology was confirmed and augmented by Cs-137, Pb-210, palynology, radiocarbon dating, and inorganic geochemical relative age markers. While some parameters exhibit multi-century fluctuations, varying excursions, and 20th century shifts, grain-size results show the clearest signal of recurring events. Several layers of enhanced silt, 1-4 cm thick, with 6-15 % more silt than background are present, in several cases correlating core to core. A Red River flood origin for these silt excursions is plausible. The results also provide indications of increased contamination, nutrient influx, and more rapid sedimentation in the 20th century.
Open Access
2006 Yellow Perch Red River Delta Data (Appendix 12)
(2006) Department of Fisheries and Oceans
Open Access
2019 Lake Winnipeg Basin Program Symposium Summary Report
(2019-08) Environment and Climate Change Canada
Environment and Climate Change Canada (ECCC) held a Lake Winnipeg Basin Program Symposium on March 20th and 21st, 2019 in Winnipeg, Manitoba in conjunction with a number of other Lake Winnipeg-related events during Canada Water Week, including the Lake Winnipeg Research Consortium’s annual Science Workshop and the launch of “Lake Winnipeg DataStream” by the Gordon Foundation. Together, the week provided the space to share new knowledge derived from scientific studies conducted on the lake and in the basin, showcase on-the-ground actions on nutrient reduction, and highlight the important collaborative partnerships that are required to address the complex issues related to water quality and quantity, including climate change. Approximately 100 stakeholders attended each day of the Symposium representing government and non-governmental organizations (NGOs), scientists, Indigenous governments, organizations and communities and regional conservation districts.
Open Access
Advances in the Integration of Watershed and Lake Modeling in the Lake Winnipeg Basin
(Government of Canada, 2010) Leon, L.F.; Booty, W.; Wong, I.; McCrimmon, C.; Melles, S.; Benoy, G.; Vanrobaeys, J.
Estimating non-point source pollution from watersheds and the effects of mitigation measures (e.g. beneficial management practices or BMPs) is an important step in managing and protecting water quality, not only at the basin level where it originates, but also at the receiving waters such as reservoirs, lakes or oceans. Lake Winnipeg is a prime example of such land-lake interactions, where eutrophication and increased algal blooms in the lake are fueled, as evidence suggests, from agricultural sources of nutrients in the region. Over the years, simulation models at the watershed level have been applied to aid in the understanding and management of surface runoff, nutrients and sediment transport processes. Similarly, models with different degrees of complexity are used to simulate the aquatic ecology and water quality in lakes. The Soil and Water Assessment Tool (SWAT) is a widely known watershed model, which provides estimations of runoff, sediment yield, and nutrient loads at a sub-basin level. Here we examine the application of SWAT to one of three pilot watersheds on the Lake Winnipeg basin in order to investigate the impacts and uncertainties of different BMPs on nutrient loading in the targeted catchment areas. We also explore avenues for scaling and propagating such loads and uncertainties into the receiving lake models.
Open Access
Agricultural Beneficial Management Practices for Lake Winnipeg – Cost-benefit analysis using an ecological goods and services approach
(The Thomsen Corporation, 2010-11) Thomsen, Joseph; Kulshreshtha, Suren; Lobb, David; Flaten, Don; MacDonald, K.Bruce
The objective of the research and analysis reported herein was to “Assess the costs and benefits of agricultural beneficial management practices (BMPs) for Lake Winnipeg in physical and economic terms, with an emphasis on the co-benefits in terms of ecological goods and services.” Lake Winnipeg is a large and key natural asset, whose watershed drains a major portion of the Canadian Prairies and part of the U.S. Great Plains. This includes almost all of the agricultural area of the Canadian Prairies. Due to a variety of factors, including increases in nutrient loading, Lake Winnipeg is experiencing increasing eutrophication. The assessment and estimation methods used were necessarily simple and straightforward. To estimate phosphorus (P) reduction potential of selected BMPs, observed levels of P exported from selected sub-regional watersheds were multiplied with measures of the performance of the BMPs relative to conventional practice. The selected study area includes the major sub-watersheds of the Manitoba portion of the Lake Winnipeg drainage basin, and comprises about 23 percent of Manitoba crop land area. (In conventional Census of Agriculture terms, the study area and surrounding regions include about 60 percent of Manitoba cropland and livestock). BMPs and their ecological goods and services (EGS) impacts and values were identified and estimated on the basis of evidence and information specific to Manitoba, Canadian Prairie, and other similar dryland agriculture, soil, and agroclimatic conditions. Economic and EGS impacts were evaluated using best available evidence from the literature and current Manitoba market prices and costs. Valuation and related methods were refined over several steps of the project. Several iterations of research revealed a significant lack of evidence as well as the data and information necessary to meet the valuation objectives of the project. Put simply, whereas the level of public awareness and concern for the current condition of Lake Winnipeg is high; and the available evidence solidly indicates that Lake Winnipeg is highly eutrophic, little to no quantitative evidence of the economic and EGS impact of the Lake’s condition was found. Main estimates are that the selected BMPs have the potential to reduce the annual export of P from Manitoba agriculture by approximately 10 percent, or just under 100 tonnes of the 1,200 tonnes of the P load to Lake Winnipeg that Manitoba agriculture is understood to currently account for. Cost-benefit ratios including EGS values or indicators for these BMPs range from 0.8 to 6.3. In other terms, relative to the estimated cost of treating outflow to the Red River by the City of Winnipeg of $164,697 per tonne of P removed, the cost of reducing P exports from agricultural sources in Manitoba using the BMPs ranges from $0 (net benefit) to $765,125 per tonne of P. Variability and uncertainty of the biophysical potential to reduce P exports to Lake Winnipeg from Manitoba agricultural sources is the greatest determinant of the viability of the BMPs from a cost benefit and EGS perspective. Best estimates of the physical capacity or potential of agricultural BMPs have a wide range, extending nearly an order of magnitude - from a reduction to an increase in P export. Unit costs and prices including EGS values are relatively small factors in comparison to the range of biophysical uncertainty and variability. Given the large size and key role of Lake Winnipeg and the Lake Winnipeg drainage area, a full and direct economic and EGS accounting and estimate of the value of the lake is warranted and strongly recommended. Amongst other things, it is recommended that this entail a coordinated effort with Manitoba government and related agencies and stakeholders. Information and data with which to do so is currently widely distributed amongst several different public and private agencies in Manitoba and other jurisdictions. Despite the key importance of Lake Winnipeg, research conducted for this project was not able to identify any initiative to draw the necessary quantitative information and data together in coordinated and systematic fashion. Cost-benefit analysis using an EGS approach could be improved by further investigation and development of quantitative evidence and supporting data of EGS associated with agricultural BMPs.
Open Access
Air-Sea CO2 flux estimates in stratified Arctic coastal waters: How wrong can we be?
(AGU, 2019-01-03) Miller, Lisa A.; Burgers, Tonya; Burt, William; Granskog, Mats; Papakyriakou, Tim
Summer near-surface seawater sampling in the Canadian Arctic revealed potential for significant errors (nearly 0.1 μmol·(m-2 s -1)) in CO2 fluxes calculated from measured air-sea CO2 gradients. River runoff and sea ice melt strongly stratify these waters, often resulting in surface mixed layers only a few meters thick and isolated from waters sampled by shipboard underway systems. Samples collected with the underway system, rosette, and small boats exposed substantial near-surface gradients in CO2 partial pressure (pCO2) over the top 7 m at many stations. Distributions of temperature, salinity, and fluorescence indicated that the sources of the CO2 system gradients varied between stations, precluding simple corrections to align subsurface data with shallower conditions. Overall, the strong summertime sink of atmospheric CO2 implied by the underway data was not supported by shallower data.
Open Access
Algae, Cyanobacteria and Water Quality
(Agriculture and Agri-Food Canada, 2002-03) Scott, N.
Algae and cyanobacteria are tiny organisms that occur naturally in saltwater and freshwater. Individual organisms can often only be seen under a microscope, although with some species , individuals can join together to form colonies visible to the naked eye. It is important to understand the similarities and differences between algae and cyanobacteria as both groups can have distinct impacts on surface water quality.
Open Access
America's animal factories: how states fail to prevent pollution from livestock waste
(Natural Resources Defense Council, 1998) Natural Resources Defense Council and Clean Water Act
Factory farms, which mass-produce animals in assembly-line fashion, have harmed aquatic life, human health and ecosystems across the nation. As industrial-sized farms stagger under the vast burden of manure they are generating, environmental disasters are inevitable. The scale of this unprecedented outpouring of animal waste is staggering: 130 times the waste generated by humans in this country each year. This section details how animal waste is poisoning our water and air. It also explains why more disasters are likely to occur unless the nation takes serious steps not only to regulate the way animal factories currently handle their waste but also to turn towards more benign methods of raising animals and managing the wastes they generate.
Open Access
AN ANALYSIS OF DIGITAL WETLAND VEGETATION MAP COVERAGES. PRODUCED BASED ON AERIAL PHOTOGRAPHY AND SATELLITE IMAGERY NETLEY-LIBAU MARSH, 2001
(Water Science and Technology Branch, Environment Canada, 2014-06) Watchorn, K. Elise
Netley-Libau Marsh, the largest coastal wetland adjoining Lake Winnipeg, has been mapped by aerial photography in the past (Grosshans et al 2004; Verbiwski 1986), indicating a trend of vegetation loss, but a lack of historic aerial photography has limited mapping efforts to sporadic intervals. Landsat imagery, though of a coarser spatial resolution, has the advantage of high temporal and spectral resolution. In this study, a classified digital vegetation map was created for Netley-Libau Marsh in 2001 using GIS software, Landsat 7 imagery, and a visual classification methodology, for the purposes of comparison with an existing digital vegetation map produced by Grosshans et al (2004) from aerial photography obtained during the same year. Visual delineation and classification of Landsat multispectral imagery was a method suitable for producing wetland maps which distinguish vegetated from non-vegetated areas with a high degree of accuracy, as compared to the truthed Grosshans et al map. Whereas that photography-based mapping exercise distinguished 23 vegetation classes grouped under six marsh zones; this study was able to successfully distinguish five marsh zones – water, not vegetated, emergent wetland vegetation, wet meadow, and upland. Further distinction and categorization of three marsh zones into seven vegetation classes was also possible, but with a lower degree of accuracy. This report describes the methods used to evaluate differences in surface area of equivalent classes between the two mapping exercises. It also provides recommendation for the future analysis of Landsat images to produce a time series of classified digital vegetation maps that may be used to explore relationships between lake and river hydrology and wetland plant cover. This knowledge will be fundamental to guide management and remediation efforts for the benefit of Netley-Libau Marsh and Lake Winnipeg.
Open Access
Analysis of the effects of the Pine Falls pulp mill on the benthic invertebrates in the Winnipeg River, Manitoba
(Department of Fisheries and Oceans, 1996-07-01) Wong, P.L.; Armstrong, L.; Bezte, C.L.; Wilkinson, P.; Lockhart, W.L.
In Oct. 1994 a comprehensive study was initiated to assess the effects of the Pine Falls Pulp and Paper Mill on the invertebrates in the Winnipeg River. A total of 20850 invertebrate specimens was collected belonging to eight major classes.
Open Access
An Annotated Bibliography on Lake Manitoba and Adjoining Waters
(Delta Marsh Field Station (University of Manitoba), 2003-11) Bortoluzzi, Tara
Lake Manitoba located in south-central Manitoba, is the thirteenth largest freshwater lake in North America, spanning approximately 4700 km2. The lake is an important resource for Manitoba in terms of fisheries, recreation, hydrology and wildlife. For the past few decades there has been a growing awareness, as a result of few studies on Lake Manitoba and its surrounding waterbodies that the water quality of the lake has been deteriorating for at least the past 30 years. This has increased the need for adequate information on the current and historical biological health of Lake Manitoba and adjoining water bodies, primarily to adequately assess of the impacts of a wide range of human influences and developments on the biological health of the lake and surrounding water bodies. This has resulted in a growing need for a comprehensive bibliography summarizing studies conducted on Lake Manitoba and adjoining water bodies. In this annotated bibliography the attempted has been to compile all substantive references addressing the current and historical biological health of Lake Manitoba. Selected water bodies that surround Lake Manitoba have also been included in the bibliography including Lake St. Martin, Waterhen Watershed, Pineimuta Lake and Marsh, Dauphin River, Fairford River, the Whitemud Watershed, and Delta Marsh. The lower Assiniboine River, from Brandon to the Assiniboine River Diversion (also known as the Portage Diversion) has also been included, along with the Assiniboine Diversion. In term of biological health, publication dealing with historical and current water quality conditions and water levels, and their effects in the above mentioned water bodies have been included in the bibliography. The effects of water quality and water levels include effects on the physical, chemical and biological features of the ecosystem. Publications containing information on historical regulation of Lake Manitoba and water levels in the lake have also been included. In total approximately 400 publications are included in this bibliography, spanning a period of over 125 years, with publications as early as 1876 included, continuing up until the beginning of 2002. In the bibliography the content of each publication has been concisely summarized. The summaries given for each publication, focus in material in the documents that pertains to Lake Manitoba and the other water bodies mentioned above. A summary table is also include in this report in Section two, to exemplify specific subject material that is contained in the publications such as various water quality parameters, and information on fisheries, flora, fauna, agriculture,recreational usage, soils and geology. The location and season of field studies is also given in the table. Locations where publications can be found, if known, are given to aid the reader in locating copies of the publications. A list of the various locations is given along with addresses, contact information, and hours of operation in Section three. Another section (section four) has also been included, which contains a brief list of historical photographs of Lake Manitoba, and select surrounding water bodies. From this bibliography it is apparent that there is a lack of information on the current and historical health of Lake Manitoba, and the majority of its surrounding water bodies. While the general hydrology of the Lake is relatively well documented, many aspects are inadequately understood, including the physical limnology and water chemistry of the lake. Water quality data is sporadically available on the lake as early as 1926. During the 1960s and 1970s there was a water quality monitoring program carried out at up to sixteen sites in the North and South Basins of the lake. However, the sampling program was reduced to six stations in 1973, with three in each basin, and in 1977 the program was eliminated all together. Furthermore, most of the data that were gathered from the sampling programs are unpublished. Today, only one sampling station exists in the entire lake located approximately 1 km offshore from the south end of the South Basin. The site has been monitoring since 1991. Much of the scientific data gathered on Lake Manitoba has been biological in nature, mostly concerning the lakes fishery. Relatively few published studies exist which have examined the algal or invertebrate composition of the lake. There is clearly an essential need for more scientific data to be gathered on the biological health of Lake Manitoba, as well as its surrounding water bodies. It should also be noted that due to the expansive amount of publications that have resulted from research studies that have been conducted at Delta Marsh only those that directly relate biological, chemical and influences from Lake Manitoba on the marsh and surrounding area, and influences on the lake from the surrounding watershed are included in this bibliography. The majority of studies conducted in Delta Marsh have also been previously sited in a bibliography compiled by den Haan (unpublished) that is currently in the final stages of complication and will be published later this year. Publications and theses resulting from work at the Delta Marsh can also be found in the Delta Marsh Field Station (University of Manitoba) Annual Reports that can be obtained through the Delta Marsh Field Station (University of Manitoba) (see locations list). It should also be noted that currently publications are still being added on a daily basis to the Manitoba Conservation and Environment Library, since the closure and the Manitoba Department of Natural Resources Library, and the transfer of its publications to the Manitoba Conservation and Environment Library. Approximately 1,000 publications are being added monthly to the library’s catalogue. As a result some publications, other than the ones included in this bibliography could exist on Lake Manitoba and the other surrounding water bodies; however they were not accessible during the compilation of this bibliography, so they may not have been included.
Open Access
Annual Exceedance Probabilities and Trends for Peak Streamflows and Annual Runoff Volumes for the Central United States During the 2011 Floods. Chapter D of 2011 Floods of the Central United States
(United States Geological Survey, 2014) Driscoll, Daniel G.; Southard, Rodney E.; Koening, Todd A.; Bender, David A.; Holmes, Rober R.
During 2011, excess precipitation resulted in widespread flooding in the Central United States with 33 fatalities and approximately $4.2 billion in damages reported in the Red River of the North, Souris, and Mississippi River Basins. At different times from late February 2011 through September 2011, various rivers in these basins had major flooding, with some locations having multiple rounds of flooding. This report provides broadscale characterizations of annual exceedance probabilities and trends for peak streamflows and annual runoff volumes for selected streamgages in the Central United States in areas affected by 2011 flooding. Annual exceedance probabilities (AEPs) were analyzed for 321 streamgages for annual peak streamflow and for 211 streamgages for annual runoff volume. Some of the most exceptional flooding was for the Souris River Basin, where of 11 streamgages considered for AEP analysis of peak streamflow, flood peaks in 2011 exceeded the next largest peak of record by at least double for 6 of the longest-term streamgages (75 to 108 years of peak-flow record). AEPs for these six streamgages were less than 1 percent. AEPs for 2011 runoff volumes were less than 1 percent for all seven Souris River streamgages considered for AEP analysis. Magnitudes of 2011 runoff volumes exceeded previous maxima by double or more for 5 of the 7 streamgages (record lengths 52 to 108 years). For the Red River of the North Basin, AEPs for 2011 runoff volumes were exceptional, with two streamgages having AEPs less than 0.2 percent, five streamgages in the range of 0.2 to 1 percent, and four streamgages in the range of 1 to 2 percent. Magnitudes of 2011 runoff volumes also were exceptional, with all 11 of the aforementioned streamgages eclipsing previous long-term (62 to 110 years) annual maxima by about one-third or more. AEPs for peak streamflows in the upper Mississippi River Basin were not exceptional, with no AEPs less than 1 percent. AEPs for annual runoff volumes indicated less frequent recurrence, with 11 streamgages having AEPs of less than 1 percent. The 2011 runoff volume for streamgage 05331000(at Saint Paul, Minnesota) exceeded the previous record (112 years of record) by about 24 percent. An especially newsworthy feature was prolonged flooding along the main stem of the Missouri River downstream from Garrison Dam (located upstream from Bismarck, North Dakota) and extending downstream throughout the length of the Missouri River. The 2011 runoff volume for streamgage 06342500 (at Bismarck) exceeded the previous (1975) maximum by about 50 percent, with an associated AEP in the range of 0.2 to 1 percent. In the Ohio River Basin, peak-streamflow AEPs were less than 2 percent for only four streamgages. Runoff-volume AEPs were less than 2 percent for only three streamgages. Along the lower Mississippi River, the largest streamflow peak in 91 years was recorded for streamgage 07289000 (at Vicksburg, Mississippi), with an associated AEP of 0.8 percent. Trends in peak streamflow were analyzed for 98 streamgages, with 67 streamgages having upward trends, 31 with downward trends, and zero with no trend. Trends in annual runoff volume were analyzed for 182 streamgages, with 145 streamgages having upward trends, 36 with downward trends, and 1 with no trend. The trend analyses used descriptive methods that did not include measures of statistical significance. A dichotomous spatial distribution in trends was apparent for both peak streamflow and annual runoff volume, with a small number of streamgages in the northwestern part of the study area having downward trends and most streamgages in the eastern part of the study area having upward trends.
Open Access
Appendix A - Water Quality Report
(International Joint Commission, 1976) International Garrison Diversion Study Board
The purpose of this part of the report is to describe the present water quality of Lakes Manitoba and Winnipeg and, to predict future water quality with and without the imposition of irrigation return flows, canal system seepage, operational wastes, municipal and industrial effluent and fish and wildlife return flows related to the planned Garrison Diversion Unit in North Dakota.
Open Access
Aquatic Communities and Contaminants in Fish from Streams of the Red River of the North Basin, Minnesota and North Dakota
(United States Geological Survey, 1995) Goldstein, R.M.
Available data on the ecology of aquatic organisms in the Red River of the North Basin, a study unit of the U.S. Geological Survey's National Water-Quality Assessment program, were collated from numerous sources. Lack of information for invertebrates and algae precluded a general summary of distribution and ecology throughout the basin. Data on fish species distributions in the major streams of the Red River of the North Basin were analyzed based on the drainage area of the stream and the number of ecoregions the stream flowed through. Species richness increased with both drainage area (log drainage area in square kilometers, R2=0.41, p=0.0055) and the number of ecoregions a river flowed through. However, theses two factors are autocorrelated because the larger the drainage, the more likely that the river will flow through more than one ecoregion. A cluster analysis identified five river groups based on similarity of species within the fish community. Analysis of trophic and taxonomic composition provided justification for the cluster groups. There were significant differences (p=0.05) in the trophic composition of the river cluster groups with respect to the number of predator species, omnivore species, benthic insectivore species, and general insectivore species. Although there were no significant differences in the number of species in the bass and sunfish family or the sucker family, the number of species in the minnow family and the darter subfamily were different (p=0.05) among the groups identified by cluster analysis. Data on contaminant concentrations in fish from the Red River of the North indicated that most trace elements and organochlorine compounds present in tissues were not at levels toxic to fish or humans. Minnesota and North Dakota have issued a fish consumption advisory based on levels of mercury and (or) PCBs found in some species.
Open Access
ArcticNet 2011 Expedition of the CCGS Amundsen
(Centre for Earth Observation Science, 2011) Asplin, Matthew G; Scharien, Randall
This document represents the data report for datasets collected by researchers based at the Centre for Earth Observation Science (CEOS), University of Manitoba, under the Sea Ice research component of the ArcticNet Network for 2011. Our group is actively involved in research that revolves around improving our understanding of ocean-sea ice-atmosphere dynamic and thermodynamic coupling, as well as how this coupling impacts the ecology of the sea ice, and the waters immediately beneath. We employ a large ensemble of ship-based sensors, and physical sampling equipment that collect sensor-based atmospheric, oceanic and sea ice data. Our data collection efforts are driven by many interlinked objectives.
Open Access
Assessing issues associated with a time-integrated fluvial fine sediment sampler
(John Wiley and Sons, Ltd, 2019-03-27) Goharrokhi, Masoud; Pahlavan, Hoda; Lobb, David A.; Owens, Philip N.; Clark, Shawn P.
Collecting a representative time‐integrated sample of fluvial fine‐grained suspended sediment (<63 μm) is an important requirement for the understanding of environmental, geomorphological, and hydrological processes operating within watersheds. This study (a) characterized the hydrodynamic behaviour of a commonly used timeintegrated fine sediment sampler (TIFSS) using an acoustic Doppler velocimeter (ADV) in controlled laboratory conditions and (b) measured the mass collection efficiency (MCE) of the sampler by an acoustic Doppler current profiler under field conditions. The laboratory results indicated that the hydrodynamic evaluations associated with the original development of the TIFSS involved an underestimation of the inlet flow velocity of the sampler that results in a significant overestimation of the theoretical MCE. The ADV data illustrated that the ratio of the inlet flow velocity of the sampler to the ambient velocity was 87% and consequently, it can be assumed that a representative sample of the ambient fine suspended particles entered into the sampler. The field results showed that the particle size distribution of the sediment collected by the TIFSS was statistically similar to that for the ambient sediment in the Red River, Manitoba, Canada. The MCE of the TIFSS in the field trials appeared to be as low as 10%. Collecting a representative sample in the field was consistent with the previous findings that the TIFSS is a suitable sampler for the collection of a representative sample of sufficient mass (e.g., >1 g) for the investigation of the properties of fluvial fine‐grained suspended sediment. Hydrodynamic evaluation of the TIFSS under a wider range of hydraulic conditions is suggested to assess the performance of the sampler during high run‐off events.
Open Access
Assessing issues associated with a time‐integrated fluvial fine sediment sampler
(John Wiley & Sons, Ltd., 2019-03-09) Goharrokhi, Masoud; Pahlavan, Hoda; Lobb, David A.; Owens, Philip; Clark, Shawn P.
Collecting a representative time‐integrated sample of fluvial fine‐grained suspended sediment (<63 μm) is an important requirement for the understanding of environmental, geomorphological, and hydrological processes operating within watersheds. This study (a) characterized the hydrodynamic behaviour of a commonly used time-integrated fine sediment sampler (TIFSS) using an acoustic Doppler velocimeter (ADV) in controlled laboratory conditions and (b) measured the mass collection efficiency (MCE) of the sampler by an acoustic Doppler current profiler under field conditions. The laboratory results indicated that the hydrodynamic evaluations associated with the original development of the TIFSS involved an underestimation of the inlet flow velocity of the sampler that results in a significant overestimation of the theoretical MCE. The ADV data illustrated that the ratio of the inlet flow velocity of the sampler to the ambient velocity was 87% and consequently, it can be assumed that a representative sample of the ambient fine suspended particles entered into the sampler. The field results showed that the particle size distribution of the sediment collected by the TIFSS was statistically similar to that for the ambient sediment in the Red River, Manitoba, Canada. The MCE of the TIFSS in the field trials appeared to be as low as 10%. Collecting a representative sample in the field was consistent with the previous findings that the TIFSS is a suitable sampler for the collection of a representative sample of sufficient mass (e.g., >1 g) for the investigation of the properties of fluvial fine‐grained suspended sediment. Hydrodynamic evaluation of the TIFSS under a wider range of hydraulic conditions is suggested to assess the performance of the sampler during high run‐off events.
Open Access
Assessing the Relative Contributions of Input, Structural, Parameter, and Output Uncertainties to Total Uncertainty in Hydrologic Modeling
(2019) Pokorny, Scott
The simulation of physical environments by hydrologic models has become common as computational power has increased. It is well known that, to simulate the hydrology of a physical environment, simplifications of that environment are needed. The simplified versions of hydrologic processes generate uncertainty, in addition to ingesting uncertainty from input data. The uncertainty from one modeling step affects the next through propagation. Although computational power has increased through time, the computational demand for uncertainty analysis still remains a common limiting factor on the level of detail an uncertainty analysis can be conducted with. This thesis generates an estimate of total uncertainty propagated from input, structural, and parameter uncertainties for the Nelson River in the Lower Nelson River Basin near the outlet to Hudson Bay, as part of the BaySys project. Each source of uncertainty was relatively partitioned for determination of the most valuable source of uncertainty for consideration in an operational environment with a limited computational budget. The results of this thesis show the complex spatial and temporal variation present in gridded climate data. This thesis also presents an ensemble-based methodology to account for the input uncertainty associated with gridded climate data subject to propagation. The ensemble of input data was propagated through an ensemble of hydrologic models. Relative sensitivities of model parameters were shown to vary temporally and based on performance metrics, suggesting that aggregated performance metrics obscure information. Lastly, relative partitions of uncertainty were compared through cumulative distribution functions. Accounting for all sources of uncertainty appeared valuable towards improving streamflow predictability, however, structural uncertainty may be the most valuable in an operational environment with a limited computational budget followed by input, and parameter uncertainty.
Open Access
Assessment of bbe Fluoroprobe for algal taxonomic discrimination in Lake Winnipeg
(2014-10-29) McCullough, Greg
This paper reports on an investigation of the capability of the bbe Moldaenke Fluoroprobe instrument for distinguishing major algal taxa. It employs a Department of Fisheries and Oceans database of Fluoroprobe data collected simultaneously with water samples later analyzed for chlorophyll fluorescence, various water quality parameters and algal taxonomy, between August and September/October 2003. The Fluoroprobe measures fluorescence at six excitation wavelengths and records both raw fluorescence intensity and estimated chlorophyll biomass concentrations of four major algal taxa. Multiple regression of the fluorescence data explains 63% of variance in chlorophyll a in samples, and predicts chlorophyll a with a root mean square error of 7% of the range of concentrations characteristic of Lake Winnipeg. Bacillariophytes and cyanophytes dominate the algal community in Lake Winnipeg, the former characteristically dominant in spring and late autumn, and the latter from midsummer through to early autumn. Multiple fluorescence successfully distinguishes and predicts bacillariophyte and cyanophyte biomass with similar success, i.e. r2 = 0.68 in both cases, although with a larger relative RMSE, at best 10% and 19% of the range in Lake Winnipeg, respectively. It is only a weak predictor of cryptophyte biomass, a subdominant group in Lake Winnipeg except at very low concentrations, and a weaker predictor of chlorophyte biomass, also a sub -dominant group in the lake. Nonetheless, by use of multiple regressions developed from the paired data set, we were able to successfully reproduce the seasonal patterns determined by microscope counts, of both dominant and subdominant groups through a mid -summer to late autumn period in 2003.
Open Access
Assessment of Nutrient Enrichment by Use of Algal-, Invertebrate-, and Fish-Community Attributes in Wadeable Streams in Ecoregions surrounding the Great Lakes
(United States Geological Survery, 2011) Frey, Jeffrey W.; Bell, Amanda H.; Hambrook Berkman, Julie A.; Lorenz, David L.
The algal, invertebrate, and fish taxa and community attributes that best reflect the effects of nutrients along a gradient of low to high nutrient concentrations in wadeable, primarily midwestern streams were determined as part of the U.S. Geological Suvey’s National Water-Quality Assessment (NAWQA) Program. Nutrient data collected from 64 sampling sites that reflected reference, agricultural, and urban influences between 1993 and 2006 were used to represent the nutrient gradient within Nutrient Ecoregion VI (Cornbelt and Northern Great Plains), VII (Mostly Glaciated Dairy Region), and VIII (Nutrient Poor Largely Glaciated Upper Midwest and Northeast). Nutrient Ecoregions VII and VIII comprise the Glacial North diatom ecoregion (GNE) and Nutrient Ecoregion VI represents the Central and Western Plains diatom ecoregion (CWPE). The diatom-ecoregion groupings were used chiefly for data analysis. The total nitrogen (TN) and total phosphorus (TP) data from 64 sites, where at least 6 nutrient samples were collected within a year at each site, were used to classify the sites into low-, medium-, and high-nutrient categories based upon the 10th and 75th percentiles of for sites within each Nutrient Ecoregion. In general, TN and TP concentrations were 3–5 times greater in Nutrient Ecoregion VI than in Nutrient Ecoregions VII and VIII. A subgroup of 54 of these 64 sites had algal-, invertebrate-, and fish-community data that were collected within the same year as the nutrients; these sites were used to assess the effects of nutrients on the biological communities. Multidimensional scaling was used to determine whether the entire region could be assessed together or whether there were regional differences between the algal, invertebrate, and fish communities. The biological communities were significantly different between the northern sites, primarily in the GNE and the southern sites, primarily in the CWPE. In the higher nutrient concentration gradient in the streams of the CWPE, algae exhibited greater differences than invertebrates and fish between all of the nutrient categories for both TN and TP; however, in the lower nutrient gradient in the streams of the GNE, invertebrates exhibited greater differences between the nutrient categories. Certain species of algae, invertebrates, and fish were more prevalent in low- and high-nutrient categories within each of the diatom ecoregions. Breakpoint analysis was used to identify the concentration at which the relations between the response variable (biological attribute) and the stressor variable (TN and TP) change. There were significant breakpoints for nutrients (TN and TP) and multiple attributes for algae, invertebrates, and fish communities within the CWPE and GNE diatom ecoregions. In general, more significant breakpoints, with lower concentrations, were found in the GNE than the more nutrient-rich CWPE. The breakpoints from all biological communities were generally about 3–5 times higher in the south (CWPE) than the north (GNE). In the north, breakpoints with similar lower concentrations were found for TN from all biological communities (around 0.60 milligram per liter) and for TP (between 0.02 and 0.03 milligram per liter) for the algae and invertebrate communities. The findings from our study suggest that the range in breakpoints for TN and TP from the GNE can be used as oligotrophic and eutrophic boundaries derived from biological response based on this ecoregion having (1) a gradient with sufficiently low to high nutrient concentrations, (2) distinctive differences in the biological communities in the low- to high-nutrient streams, (3) similarity of breakpoints within algal, invertebrate, and fish communities, (4) significant attributes with either direct relations to nutrients or traditional changes in community structure (that is, decreases in sensitive species or increases in tolerant species), and (5) similar breakpoints in other studies in this and other regions. In nutrient-rich areas like the CWPE, all of the breakpoints were substantially higher than those for the lower nutrient conditions of the GNE, suggesting that streams are nutrient saturated to the point that low-end breakpoints cannot be detected.