Quebec River Research Articles

Comparison of the interannual variability of spring heavy floods characteristics of tributaries of the St. Lawrence River in Quebec (Canada)

Comparison of the interannual variability of five characteristics (magnitude, duration, timing, frequency, and variability) of spring heavy floods was carried out for 17 natural rivers in Quebec for the period from 1934 to 2004 to detect any effect of climate warming on these characteristics. This was done using the Lombard method and Copula. Changes in the mean and variance of all characteristics of streamflow were observed, and all these changes are abrupt. Whereas little significant change was observed in the magnitude, duration and variability (CV) series of spring flood flows. A significant change was noted in the frequency (diminution) for five rivers and in the timing of spring floods for six rivers. However, the change in mean timing is the only one that has a hydroclimatic significance in time and space. This change was observed, on the one hand, in the Eastern hydrological region, located on the south shore of the St. Lawrence River, north of 47°N, and characterized by a maritime climate and, on the other hand, in the South-west hydrological region, located on the north shore and characterized by a continental climate. In both cases, the change took place after the second half of the 1970s and is characterized by the early occurrence of spring floods. In addition, in both hydrological regions, the timing of spring floods is correlated with the same hydroclimatic indices, showing a positive correlation with the North Atlantic Oscillation (NAO) and a negative correlation with the Atlantic Multidecadal Oscillation (AMO). Frequency is the only characteristic for which mean and variance changed significantly over time for the same rivers (4), all located north of 48°N, on both shores of the St. Lawrence. For all flow characteristics, the change in variance can predate, postdate or be synchronous with the change in mean. Finally, the dependence between the various characteristics of spring floods as determined using the Kendall tau statistic remained constant in time for most of the rivers.

Climate Change and Floodplain Delineation in Two Southern Quebec River Basins1

Laforce, Serge, Marie-Claude Simard, Robert Leconte, and François Brissette, 2011. Climate Change and Floodplain Delineation in Two Southern Quebec River Basins. Journal of the American Water Resources Association (JAWRA) 47(4):785-799. DOI: 10.1111/j.1752-1688.2011.00560.x Abstract: A methodology is presented for mapping the flooded extent of rivers under projected climate change. The methodology follows a top-down modeling approach, where future climate projections generated by global climate models (GCMs) are downscaled to the watershed scale and used as input to hydrological and hydrodynamic models for predicting future river flows and associated open water levels. A range of possible future climate responses are taken into account, allowing quantification of flood-mapping uncertainties resulting from GCM structure and greenhouse gas emission scenarios (GHGES). Probabilistic projections of future flood zones are developed by assuming that all GCMs and GHGES be equally weighted. The proposed methodology was applied to two river basins located in southern Quebec, Canada, for the time horizons 2020 and 2080. Twenty- and hundred-year floods were computed and corresponding flood maps have been produced. Results indicate that there is a general trend toward an increased spring peak discharge for the Châteauguay River Basin and a decrease for the du Nord River Basin at the 2020 horizon. A less obvious trend was observed for the 2080 horizon, some GCM-GHGES producing an increase in spring peak flows, whereas others would result in a less severe spring flood. These uncertainties in flood flows have cascaded into uncertainties in the corresponding flooded extent and represented as probabilistic flood maps.

The North Atlantic subpolar gyre and the marine migration of Atlantic salmon Salmo salar: the ‘Merry‐Go‐Round’ hypothesis

One model for marine migration of Atlantic salmon Salmo salar proposes that North American and southern European stocks (<62 degrees N) move directly to feeding grounds off west Greenland, then overwinter in the Labrador Sea, whereas northern European stocks (>62 degrees N) utilize the Norwegian Sea. An alternate model proposes that both North American and European stocks migrate in the North Atlantic Subpolar Gyre (NASpG) where S. salar enter the NASpG on their respective sides of the Atlantic, and travel counterclockwise within the NASpG until returning to natal rivers. A review of data accumulated during the last 50 years suggests a gyre model is most probable. Freshwater parr metamorphose into smolts which have morphological, physiological and behavioural adaptations of epipelagic, marine fishes. Former high-seas fisheries were seasonally sequential and moved in the direction of NASpG currents, and catches were highest along the main axis of the NASpG. Marking and discrimination studies indicate mixed continental origin feeding aggregations on both sides of the Atlantic. Marked North American smolts were captured off Norway, the Faroe Islands, east and west Greenland, and adults tagged at the Faroes were recovered in Canadian rivers. Marked European smolts were recovered off Newfoundland and Labrador, west and east Greenland, and adults tagged in the Labrador Sea were captured in European rivers. High Caesium-137 ((137)Cs) levels in S. salar returning to a Quebec river suggested 62.3% had fed at or east of Iceland, whereas levels in 1 sea-winter (SW) Atlantic Canada returnees indicated 24.7% had fed east of the Faroes. Lower levels of (137)Cs in returning 1SW Irish fish suggest much of their growth occurred in the western Atlantic. These data suggest marine migration of S. salar follows a gyre model and is similar to other open-ocean migrations of epipelagic fishes.

Abiotic variables accounting for presence of the exotic rainbow trout (Oncorhynchus mykiss) in Eastern Quebec Rivers

Key-words: invasion success, abiotic filter, geomorphological variables, climatic variables, logistic regression modelling Rainbow trout is an exotic fish species that has been introduced in Quebec (Canada) since 1893–1894. Despite spatially-restricted stocking for recreational fishing, the species has spread throughout the Saint Lawrence River. In this study, the relationship between rainbow trout occurrence (presence or absence) and abiotic variables (river geomorphology and climate) was examined for 91 coastal rivers throughout Eastern Quebec in order to determine which variables promote or impede the ongoing invasion process. Results revealed that rainbow trout presence in Eastern Quebec was primarily determined by geomorphological parameters. The invader’s presence was strongly related to the presence of tributaries (especially larger ones). To a lesser extent, the presence of rainbow trout was positively related to warm spring and summer temperatures and negatively related to the peak flood date occurring during the egg deposition period (May). This study proposes a parsimonious modelling approach to identify which environmental parameters favour the spreading of an invader, even when a limited dataset is available due to the incomplete invasion process.

Patterns inpCO2in boreal streams and rivers of northern Quebec, Canada

Here we examine the patterns in carbon dioxide partial pressure (pCO2) measured in a number of small boreal streams (&lt;5 km in length) in the northwestern boreal region of Québec during the ice‐free season and compare these to the patterns found in a major river (Eastmain River) and in a tributary in the same region. All systems were consistently supersaturated in CO2(range 450 to 5000μatm) streams having both higher (mean 1850μatm) and more variablepCO2than that of rivers (range 550 to 800μatm). StreampCO2was positively related to DOC concentration and stream segment length, both suggesting a direct influence of the surrounding landscape. Calculated stream water‐air CO2fluxes ranged from 700 to over 3000 mg C m−2d−1, up to 2 orders of magnitude higher than those measured in large rivers and lakes of the same region. Small streams, despite their extremely reduced areal coverage (1% of the aquatic surface), accounted for 25% of the total aquatic C emissions, and the resulting areal stream fluxes were comparable to those measured in different soils or wetlands in the region.

Modeling anchor ice presence–absence in gravel bed rivers

Abstract We studied the meteorological and hydraulic conditions conducive to anchor ice formation in three gravel bed rivers of southern Quebec (Beauport, Duberger and York rivers). First, a dataset including the dichotomous response variable presence–absence of anchor ice in a river reach, and ten continuous predictors related to air temperature (freezing degree-hours FDH cumulated over 6, 8, 12, 24 and 48 h) and water temperature (W averaged over 6, 8, 12, 24 and 48 h) was used to develop a logistic regression model of anchor ice presence at the river reach level. The model developed in this study used the variable FDH-12 to correctly predict 80.9% of the anchor ice presence–absence observations. More specifically, it predicted that anchor ice is more likely to form when a threshold FDH-12 value of 111.7 °C-h is exceeded. Second, data on the presence of anchor ice at the parcel level (0.25 m 2 ) was collected at the Beauport and Duberger study reaches in order to determine the effect of local hydraulic conditions on the formation of anchor ice. Covariates common to all parcels within a river reach (air and water temperature) and hydraulic variables specific to each parcel (flow velocity, water depth, Froude and Reynolds numbers) were used as explanatory variables. The results of the stepwise hierarchical logistic regression analysis showed that the Froude number was the first variable to enter the model and that it could not be improved significantly by adding any other variable. The model correctly classified 67.5% of the presence–absence observations of anchor ice on the parcels and indicated that anchor ice was most likely to form at Froude values larger than 0.1.

Use geopedological methods for the evaluation of sedimentation rates on river floodplains, southern Québec, Canada

Abstract This article pertains to the fluvial dynamics of rivers in southern Quebec, in particular to the aggradation and pedogenetic processes observed in floodplains affected by periodic floods. The frequency of flood events, notably along the Saint-Francois River and its main tributaries, leads to fine materials being frequently deposited on floodplains and affected development of alluvial soils. Particle size and physical and chemical analyses have led to a better understanding of the dynamics involved in the formation of floodplains and the development of soils related to this fluvial environment. Also, sedimentological analyses (layer texture and thickness, microstructure) combined with radiocarbon dating (14C) and isotopic methods (210Pb, 226Rd) enabled the determination of sedimentation rates along the floodplains. The radiocarbon dating results obtained from the organic layers buried in alluvial soils show relatively variable ages, i.e. between 2210 ± 60 and 30 ± 70 years BP. The data gathered reveal an active overbank deposition, which shows evidence of the high flood recurrence in many rivers of the basin. It is estimated that the annual floodplain aggradation ranges from 1.0 to 7.6 mm yr− 1 on average, which causes increases in floodplain elevations (vertical accretion). The sedimentation rates obtained using the constant rate supply dating model (210Pb) show average values that range from 2.1 to 10.7 mm yr− 1. Also, the presence of contaminated layers at the lower level (> 100 cm) of the floodplains suggested an active sedimentation rates along the rivers affected by floods.

The Development and Application of Multimetric Indices for the Assessment of Impacts to Fish Assemblages in Large Rivers: A Review of Current Science and Applications

The biological assessment of lotic resources in much of the U.S. and Canada initially focused on wadeable rivers and streams. However, increased emphasis is being placed on larger, non-wadeable rivers. Many of these efforts include the development of multimetric indices represented by the Index of Biotic Integrity (IBI) following the original developmental work in the U.S. They include the pioneering work in the Wabash River of the Midwestern U.S., the inland rivers of Ohio and Wisconsin, the Ohio River mainstem, large western rivers and Quebec rivers, all of which focused on the fish assemblage. Monitoring fish assemblages in large rivers includes logistical and technical considerations that affect obtaining reliable estimates of relative abundance for all species that are amenable to efficient capture. A single gear approach is preferred for practical reasons and electrofishing is the sampling method of choice. Sampling effort is expressed in terms of distance sampled at a site and includes formulas based on fixed distances or multiples of river channel width. Relative abundance data are analyzed via multimetric indices (e.g., Index of Biotic Integrity), which are contingent on the development of a reference condition that supports a derivation and calibration process. Defining reference for large rivers represents a different challenge than with smaller, wadeable streams. For the latter, sufficient and suitable reference analogs usually exist, thus reference condition can be empirically derived. However, such analogs are either rare or do not adequately reflect the restorable potential for large rivers. Thus in developing the expectations that are necessary for metric calibration and IBI development, adequate historical knowledge of the assemblage is critical. Once developed, the metrics and indices provide meaningful measures of assemblage quality and response to chemical, physical, and biological influences and perturbations. This has been demonstrated for a wide variety of human impacts including water pollution, habitat and flow alterations, and land use changes. Successfully applying this protocol to large rivers involves taking the correct sequence of steps in the initial development of sampling and assessment methodologies. The IBI serves not only as an important benchmark of aquatic resource quality and condition, but also as a test of the significance of human impact on the aquatic environment. Developing and implementing a multimetric approach for large, coldwater rivers is feasible and would serve as a useful assessment and planning tool for determining the magnitude and severity of impacts from riverine flow and habitat modifications.

Dynamic tracking of flow boundaries in rivers with respect to discharge

A new Eulerian approach is proposed to track the dynamic position of flow boundaries in rivers with respect to flow discharge or tides. Associated to a two dimensional (2D) transient horizontal hydrodynamic model, it allows to define the configuration of watercourses in a broad hydrological register varying from dry conditions to severe flooding. The finite element method is used to develop the numerical prediction tool. It is employed to estimate not only the classical flow variables such as water surface level and velocity field, but also the position of the shorelines. In this paper, the strategy followed for building this «drying-wetting» model consists in letting the water surface move freely, everywhere in the domain including the dry zones, allowing it to plunge under the ground. Two practical applications on rivers of Quebec (Canada) are presented. The first one deals with steady state situations on St. Marguerite River. The second one deals with the reconstitution of flood propagation on Chicoutimi River according to the extreme flooding events of July 96 in the Saguenay region.

The impact of climate change on seasonal floods of a southern Quebec River Basin

AbstractGlobal warming predicted by general circulation models (GCM) is now a more and more generally agreed upon effect. The impact of climate change on summer and fall flooding on the Châteauguay River Basin (2500 km2), located at the southern end of the Quebec province (Canada), was investigated using results from the Canadian GCM (CGCM1) and a coupled hydrology–hydraulics model of the basin. Three 20‐year periods, corresponding to 1975–1995, 2020–2040 and 2080–2100, were used for the analysis. For each period, 24‐h precipitation depths corresponding to the 20 and 100‐year return periods were determined from a frequency analysis of the summer–fall maximum 24‐h precipitations using a general extreme value frequency distribution. 24‐h rainfall hyetographs were generated using region‐specific cumulative distributions provided by the Canadian Atmospheric Environment Service. These hyetographs were then used as inputs to the hydrology–hydraulics model to simulate hydrographs, maximum discharge and maximum water levels at two sections of the river. Results indicate potentially very serious increases in the volume of runoff, maximum discharge and water level with future climate change scenarios. The changes get more drastic as longer return periods are considered. Increases of up to 250% of the maximum water discharge are encountered and water levels are significantly higher than the current flood levels. If realistic, these scenarios indicate that important decisions will have to be taken to alleviate future increases in flooding damages in what is already a flood prone river. Copyright © 2001 John Wiley &amp; Sons, Ltd.

Stochastic Procedure for Generating Seasonal Flows

The generation of seasonal flows that can reproduce the historic basic statistics at more than one aggregation level is usually desirable for most reservoir simulation studies. The objective of this paper is to propose a stochastic procedure for generating seasonal flows at one or several sites. The proposed procedure combines a singular value decomposition (SVD) with a multivariate autoregressive of order one AR(1) model [SVD/MAR(1)]. The SVD transforms a standardized matrix of normalized flows into its standardized principal components, and the MAR(1) model is applied to the standardized principal components matrix. The SVD/MAR(1) procedure was compared with the existing SVD and MAR(1) approaches using the Great Lakes and Quebec rivers data. It can be concluded that the proposed SVD/MAR(1) procedure is applicable where the available flow data are limited and/or the number of considered sites is large. Furthermore, it can preserve adequately the basic statistics and some drought related properties of historic monthly and annual flows.

Application de la fonction bêta et des polynômes de Jacobi à l'analyse des valeurs extrêmes

In this paper, an improved probabilistic method for flood analysis using the probable maximum flood, the beta function, and orthogonal Jacobi’s polynomials is proposed. The shape of the beta function depends on the sample's characteristics and the bounds of the phenomenon. On the other hand, a serial of Jacobi’s polynomials has been used improving the beta function and increasing its convergence degree toward the real flood probability density function. This mathematical model has been tested using a sample of 1000 generated beta random data. Finally, some practical applications with real data series, from important Quebec's rivers, have been performed; the model solutions for these rivers showed the accuracy of this new method in flood frequency estimation. Key words: probable maximum flood, beta function, orthogonal polynomials, distribution function, flood frequency estimation, data generation, convergency.

Empirical models for estimating the concentrations and exports of metals in rural rivers and streams

Concentrations of Al, Fe, Mn, Zn and Cu were measured monthly at 24 sites in 21 rivers in Ontario and Quebec. Relationships between metal and suspended particulate matter (SPM), turbidity, colour (g440), temperature and system hydrology were quantified, and used to derive empirical models for predicting metal concentrations. In a test of the models using an independent data set, they explained a significant proportion of the variation in Al (90%), Fe (85%), and Mn (57%), but only 37% of the variation in riverine Zn concentrations. Metals concentrations are most strongly associated with SPM concentrations. The proportion of the total metal load associated with particulates (>0.45 μm) is highly variable below 10 ppm SPM, indicating that this concentration approximates the division between systems dominated by weathered (solution) versus eroded (particulate) inputs. Annual metal exports were calculated, and empirical models for predicting catchment exports were developed using system hydrology and average SPM concentrations. These simple models can be used to estimate metals concentrations and exports from routine water quality monitoring data, without requiring chemical analyses. They also serve to distinguish background levels from those indicating metal contamination, and will, therefore, be useful for water quality evaluation.

Identification externe du sexe chez le Saumon atlantique (Salmo salar L.)

A technique to determine the sex of the atlantic salmon (Salmo salar) from external features is proposed. A total of 214 individuals caught in July and August 1986 in five rivers in Quebec and at a salt water location have been studied. Overall, the sexual dimorphism of the relative length of the upper jaw bone allowed us to sex the fishes with 88% success.

Colloidal and dissolved organic carbon dynamics in undisturbed boreal forest catchments: a seasonal study of apparent molecular weight spectra

SUMMARY. 1. Colloidal and dissolved organic carbon (CDOC) was monitored in six pristine boreal rivers in Northern Quebec, Canada, using ultrafiltration to obtain apparent molecular weight spectra.2. The concentration and proportional contribution of small (&lt;1K) molecular weight material (potentially microbially labile) and high (0.7μm to 300 K) molecular weight material was not significantly different between streams of order 2–9.3. The dominant component of CDOC (0.7μm to 300 K fraction) was probably derived in streams other than first order, from surface or sub‐surface run‐off, whereas a peak concentration in the &lt;1 K fraction during August was probably due to autochthonous exudates.4. The two first order streams included in this survey had very low CDOC concentrations. However, further work on twelve other first order streams showed that they had high concentrations and we consider that this is the more typical situation. The finding offered a potential explanation for the otherwise anomalous longitudinal CDOC distribution pattern throughout the study area.

Etude préliminaire des effets de la mise en eau du Réservoir de LG‐2 (Territoire de la Baie James, Québec) sur le seston grossier et le zooplancton des rivières et des lacs inondés

Preliminary Study of the Effects of Impoundment of LG‐2 Reservoir (James Bay Territory, Quebec) on the Net Seston and the Zooplankton of Impounded Rivers and LakesThe effects of impoundment on the biomass of net seston and zooplankton in lakes and rivers of Northern Quebec were investigated from 1978 to 1980, before, during and after the completion of LG2 Reservoir on the River La Grande (53° 54′ N, 76° 78′ W). In lotic stations, a 41–77% decrease in net seston was observed due to sedimentation of mineral particles (36–80 mg/m3 in 1978 to 10–21 mg/m3 in 1979). The ratio of organic to total seston increased from an average of 0.18 before the impoundment to 0.65 after. The flooding phase brought about a trophic upsurge; the biomass of the zooplankton increased by one to two orders of magnitude at the various sites; the greatest increases occurred in the central stations near the dam, the smallest in the upper stations near the inflow. In lake stations, no significant difference between years could be detected; the mean zooplankton biomass for all three years ranged from 6.59 mg/m3 to 34.34 mg/m3. Spatial variations between lakes were however significant. Results are compared with those in other natural lakes in Canada and reservoirs in the United States. Comparative examination of phytoplankton biomass before and after impoundment of LG2 Reservoir suggests that bacterioplankton and allochthonous organic material are key elements in the pelagic food chain after impoundment.

Étude des relations entre les communautés piscicoles et les différents habitats d'une rivière nordique: notion d'habitat optimal

A complete linkage cluster analysis using the physical characteristics of the sampling sites has revealed the existence of five groups corresponding to five habitat types nonequally distributed in a northern Quebec river. According to the results of discriminant analysis using the relative abundance of the fish species present, these habitats support populations which differ by the relative abundance of species and not by the presence or absence of some particular species. A habitat is first characterized by a species living preferentially in this habitat, then by the other species inhabiting the area in an opportunistic way, and finally by some satellite species which do not seem to have any marked requirements. A habitat is considered as optimal for a species first if this species inhabits this area preferentially to others and secondly if this use is more advantageous for growth or condition factor. This seems to be confirmed for two of the most abundant species, northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis), both of which have a higher condition factor and a better growth in the part of the river where their optimal habitat is more frequently found.

Morphological and dietary variations in a riverine population ofPycnopsyche guttifer(trichoptera: Limnephilidae)

Abstract P. guttifer is typically found associated with allochthonous debris in slow‐water areas of streams where it is said to function as a classical shredder. A population of 5th instar larvae from a large Quebec river appears to depart from this ideal in that many were found in areas of the river where current speeds exceed 30 cm/ s, and many were eating predominantly algae thus exhibiting features of the scraper trophic category. Considerable variations in larval and case dimensions were noted, some of which are related to features of the microhabitat. The need for more data, from a variety of field conditions and localities, on so‐called well‐known species is discussed.

Analyse multivariée et interprétation géochimique de la variabilité spatiale de la qualité de l'eau des rivières du Québec méridional

An analysis of the spatial variability of a group of parameters, measured at 62 sampling stations on southern Quebec rivers, was achieved by means of correspondence analysis. These parameters are calcium, magnesium, sodium, potassium, sulphate, chloride, silica and conductivity. The application of a clustering method to the results of correspondence analysis led to the definition of four homogeneous zones, which is based on the common behaviour of sampling stations as a function of the measured parameters. Among the zones thus determined, three zones correspond to the Laurentian Plateau, the Appalachian Mountains and the St. Lawrence Lowlands, while the fourth overlaps the last two regions mentioned. It is possible to show that the behaviour of each zone is related to the relief and to the geological characteristics of its geographical situation in southern Quebec.

Selectivity of fly-fishing, spinning and gillnet for brook charr and ouananiche in a large northern Quebec river

A comparison between fly-fishing, spinning and short 51 mm and 25 mm gill nets showed that fly-fishing was the least selective method of sampling brook chary,Salvelinus fontinalis, and ouananiche,Salmo salar, in rapid sections of the Caniapiscau River, north central Quebec. Angling techniques had the added advantage of mobility which allowed rapids to be more evenly covered during sampling. Selectivity curves for the capture of brook chary by fly-fishing, spinning and a 51 mm mesh gill net are presented.