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Rainfall peak flow response to clearcutting 50% of three small watersheds in a boreal forest, Montmorency Forest, Québec
Abstract
The scientific literature suggests that a 50% increase in bankfull discharge can significantly modified stream morphology and that such increases could be avoided by clearcutting less than 50% of the watershed area. Also hypothesized is that clearcutting near the stream network could have greater effect on peak flow than harvesting a comparable area further away. Following a 5-year calibration period, three small watersheds (<50 ha) within the "Ruisseau des Eaux-Volées" Experimental Watershed (REVEW) at Montmorency Forest (Quebec, Canada) were harvested over 50% of their areas. Regeneration was protected and logging was carried out when snow cover was present to prevent soil perturbation. A neighbouring watershed was maintained undisturbed as control. During the two summers following logging and for all treated watersheds, analysis of regression lines indicated non-significant peak flow increases and bankfull discharge augmentations below the 50% threshold. Proximity of harvested areas to stream network had no significant effect on increase in bankfull discharge. Furthermore, the smallest augmentation was recorded on the watershed where the harvested area was closest to the stream network. For all treated watersheds, one particularly intense rainstorm (resulting from after effects of Hurricane Katrina) significantly increased peak flows above the upper confidence limit of the pre-treatment regression lines. These individual bankfull increases were all above 50% indicating that the 50% cutting threshold may not be applicable to very small watersheds. However, that particular meteorological event was exceptional and given a harvesting rotation of 80 years, the probability for peak flow to augment above 50% was increased by only 3%.
... Being a hanging valley of 1.25 km 2 surface area with an elevation of 775-975 m ASL and a topographic slope of approximately 15% on the valley flanks and 10% at the valley bottom, sub-ba-sin 7A strongly resembles the tilted-V benchmark model used widely in numerical SW-GW studies (Kurtz et al., 2017;Maxwell et al., 2014;Panday & Huyakorn, 2004). Owing to its model character, 7A has a long history as a site for hydrological methods development (Barry et al., 1988;Hadiwijaya et al., 2020;Isabelle et al., 2018Isabelle et al., , 2020aIsabelle et al., , 2020bLavigne, 2007;Sklash & Farvolden, 1979;Tremblay et al., 2008Tremblay et al., , 2009 Overview of the BEREV, the sub-basins and the monitoring infrastructure. Subbasin 7A is highlighted by a yellow glow. ...
... Coordinate system: IGNF:WGS84 G. Orthoimage: Esri (2019). Parent, 2018;Rochette, 1971;Sklash & Farvolden, 1979;Tremblay Otis, 2018;Tremblay et al., 2008Tremblay et al., , 2009). The unconsolidated glacial deposits are covered by 0-1 m of soil (classification: Ferro-Humic Podzol) (Tremblay et al., 2008(Tremblay et al., , 2009) and consist mainly of sand and gravel, forming a variably permeable and anisotropic aquifer (Table 1). ...
... Parent, 2018;Rochette, 1971;Sklash & Farvolden, 1979;Tremblay Otis, 2018;Tremblay et al., 2008Tremblay et al., , 2009). The unconsolidated glacial deposits are covered by 0-1 m of soil (classification: Ferro-Humic Podzol) (Tremblay et al., 2008(Tremblay et al., , 2009) and consist mainly of sand and gravel, forming a variably permeable and anisotropic aquifer (Table 1). In the center of 7A and several other sub-basins of the BEREV, an extensive layer of compacted alluvial deposits was identified (a mix of soil, sand and silt; classification: Fragipan and Ortstein) (Figure 1), likely formed by a combination of washout and deposition of fine materials as well as compacting by pronounced snowfall, snowmelt and freeze-thaw processes (Barry et al., 1988;Légaré-Couture & Parent, 2018;Rochette, 1971). ...
Snowmelt contributes a significant fraction of groundwater recharge in snow-dominated regions, making its accurate quantification crucial for sustainable water resources management. While several components of the hydrological cycle can be measured directly, catchment-scale recharge can only be quantified indirectly. Stable water isotopes are often used as tracers to estimate snowmelt recharge, even though estimates based on stable water isotopes are biased due to the large variations of 2H and 18O in snow and the difficulty to measure snowmelt directly. To overcome this gap, a new tracer method based on on-site measurements of dissolved He, 40Ar, 84Kr, N2, O2 and CO2 is presented. The new method was developed alongside classical tracer methods (stable water isotopes, 222Rn, 3H/3He) in a highly instrumented boreal catchment. By revealing (noble gas) recharge temperatures and excess air, dissolved gases allow (i) the contribution of snowmelt to recharge, (ii) the temporal recharge dynamics, and (iii) the primary recharge pathways to be identified. In contrast to stable water isotopes, which produced highly inconsistent snowmelt recharge estimates for the experimental catchment, dissolved gases produced consistent estimates even when the temperature of snowmelt during recharge was not precisely known. As dissolved gases are not controlled by the same processes as stable water isotopes, they are not prone to the same biases and represent a highly complementary tracer method for the quantification of snowmelt recharge dynamics in snow-dominated regions. Furthermore, an observed systematic depletion of N2 in groundwater provides new evidence for the pathways of biological N-fixation in boreal forest soils.
... located 80 km north of Quebec City, Canada, in the Laurentian Mountains. The field site lies within a 1.2-km 2 experimental watershed, part of the "Bassin Expérimental du Ruisseau des Eaux-Volées" (BEREV) (Lavigne, 2007;Tremblay et al., 2008Tremblay et al., , 2009Noël et al., 2014). The BEREV has a mean altitude of 750 m above mean sea level (AMSL) with hills reaching 1000 m AMSL. ...
... The vicinity of the experimental setup is on a 12° slope facing northeast. The vegetation of the watershed is mostly composed of balsam fir (Abies balsamea (L.) Mill) mixed with white birch (Betula papyrifera Marsh) and white spruce (Picea glauca (Moench) Voss) (Lavigne, 2007;Tremblay et al., 2008Tremblay et al., , 2009). ...
... (BEREV) (Lavigne, 2007;Tremblay et al., 2008Tremblay et al., , 2009Nöel et al., 2014;Isabelle et al., 2018a). This experimental watershed lies at a mean altitude of 750 m above mean sea level (AMSL) with peaks at 1000 m AMSL. Figure 2.1a presents the boundaries of two sub-catchments of the BEREV covering an area of 3.49 km 2 . ...
The boreal forest covers 30% of Canada's surface and 14% of the earth's land surface. Climate change will severely affect it, and these ecosystems will in turn impact climate and global hydrology with significant exchanges of water, energy and carbon between the soil and the atmosphere. It is now crucial to understand the surface energy balance of this biome to effectively predict its behavior and evolution in a changing climate. Many studies have analyzed the energy balance of the boreal forest, but significant gaps remain: there are little studies in non-flat terrain, or in areas receiving significant rainfall, or with measurements at various spatial scales, let alone combinations of these three possibilities.
The main aim of this thesis is to fill these gaps with a rigorous analysis of the energy balance and evapotranspiration of a boreal forest covering a pronounced topography, and this at several spatial scales (point: ~m2, local: ~ha, regional: ~km2). The results are mainly based on a measurement campaign taking place at the Montmorency Forest of Université Laval, 80 km north of Québec, Canada. The forest is a balsam fir – white birch forest with trees of varying degrees of maturity. There, two flux towers are measuring all the energy balance terms since autumn 2015. Three specific objectives are associated with three spatial scales of measurement or modeling in a gradient from the point scale to the regional scale.
In a first objective, the spatial heterogeneity of the forest cover is characterized by sub-canopy solar radiation measurements. Then, the vegetation density evaluation makes it possible to parameterize a land-surface scheme to obtain the variability of the evapotranspiration and its components. The results show that even though the transmission of radiation is highly variable from point to point (seasonal average between 7% and 69%), a spatial average at the local scale represents the area quite well. Modeling results indicate that a denser forest causes slightly more total evapotranspiration because it evaporates more intercepted precipitation and generates more transpiration. A denser forest, however, evaporates less water on the ground, which can lead to increased soil moisture under conditions of momentary drought.
In the second objective, the impact of heavy rainfall on the local energy balance and evapotranspiration in the boreal forest is evaluated. To do this, the main site of Montmorency Forest is first compared with 13 boreal forest sites around the world on the basis of energy balance and evapotranspiration. The Montmorency Forest is the site receiving the most rainfall with ~1600 mm y-1. For all sites, the precipitation received is positively related to annual evapotranspiration, which means the main site has the highest evapotranspiration rates, with ~550 mm y-1. With accurate measurements of the outflow from the 3.5 km2 watershed containing the Montmorency Forest measurement sites, the water balance is clearly established: excess water from precipitation is mainly discharged through outflows of the watershed, to an extent of ~1050 mm y-1.
For the third objective, the two-wavelength scintillometry method is evaluated at the study site and its regional energy balance measurements are compared to those at the local scale. The scintillometers are installed across a valley where one of the two flux towers is localized. The scintillometers’ electromagnetic beams travel 1347 m at a height varying between 5 and 100 m and an effective height of 88 m. The results show that the two experimental systems have a low agreement in terms of the meteorological structure parameters, but a more than acceptable agreement for the turbulent fluxes. For the latter, the correlation between scintillometers and flux tower is optimal when the electromagnetic beams are entirely included in the atmospheric surface layer. However, since the beam height is highly variable, they are more often than not partially present in the atmospheric surface layer anyway, which leads to a correlation that is still acceptable in these circumstances. However, measurements of scintillometers are often unrealistic during nocturnal periods and when the atmosphere is stable.
In short, the studied boreal forest exhibits an energy balance and evapotranspiration significantly different from other sites in similar biomes referenced in the literature. This thesis provides important details on this type of environment. In addition, the thesis offers rigorous methodological tools to assess the energy balance at various spatial scales and elaborates on the possibility of upscaling and/or downscaling results, a contribution not to be overlooked for hydrological and climate modelers in Canada and around the world.
... Mitsch et Gosselink (2015) nuancent davantage ces affirmations en mentionnant que certains milieux humides contribuent à régulariser l'écoulement. Cependant, lors d'événements extrêmes (récurrence de 50-100 ans), il est bien reconnu que la présence de milieux humides (Adamus et Stockwell 1983;Taylor et al. 1990;Acreman et Holden 2013), ou de forêts (Cosandey et Robinson 2000;Calder 2005;Guillemette et al. 2005;Tremblay et al. 2008;Grant et al. 2008; Barry et al. 2009) dans un bassin versant ne peuvent pas contrôler les inondations qui découlent de ces événements. Le rôle des milieux humides sur l'atténuation des crues est nettement exagéré selon plusieurs auteurs (Simonovic et Juliano 2001;Kvaerner et Klove 2008). ...
... Lu (1994), à l'aide de la modélisation, a estimé que les débits de pointe ayant une période de retour de 25 ans et plus ne présentent pas d'augmentation significative après la récolte, ce qui est conforme à la tendance acceptée par la communauté scientifique. Cependant, cette augmentation du débit de pointe est plus élevée que celles observées lors d'autres études provenant des bassins expérimentaux (Guillemette et al. 2005;Tremblay et al. 2008) pour des périodes de retour dépassant 1,5 an. La forte augmentation des débits de pointe observée est possiblement reliée à une synchronisation des écoulements provenant des versants (fonte des neiges plus tôt) et de la présence de deux exutoires drainant le bog, ce qui raccourcit le cheminement de l'eau (Verry et al. 1983;Verry 1987;Lu 1994;Sebestyen et al. 2011aSebestyen et al. , 2011b. ...
The protection of ecological functions of forested swamps and peatlands is the subject of legal and regulatory measures. In Quebec and elsewhere in Canada, wood harvesting is carried out on swamps and peatlands of merchantable forests. What is the impact of forestry practices on these wetlands hydrological functions such as sediment retention, groundwater recharge, flood reduction and low flow augmentation? The answer to this question is complex as the contribution of wetlands to these hydrological functions vary with each wetland type as underlined by the experts. With the aim of ascertaining the contribution of wetlands, and to infer the effects of forest management on forested swamps and peatlands, we carried out a literature review. The existing literature reviews only partially cover the subject or in the case of peatlands, they mainly consider drained sites. In this review, the links between the hydrologic functions and forest harvesting are treated by category of wetlands to take into account their anticipated specific contribution.
... The mean annual temperature and precipitation are 0.5 • C and 1583 mm (61% rain, 39% snow), respectively [52]. The site is located within the balsam fir-white birch bioclimatic domain, the dominant vegetation being balsam fir (Abies balsamea (L.) Mill.) with sparse occurrences of white birch (Betula papyrifera Marsh), white spruce (Picea glauca (Moench) Voss) and black spruce (Picea mariana Mill.) [53,54]. ...
... The measurement sites were located around two eddy-covariance towers in an experimental watershed ( Figure 1a) called the "Bassin Expérimental du Ruisseau des Eaux-Volées" (BEREV) [53][54][55][56]. The first tower is surrounded by a young tree stand that developed after an 85% clear cut that occurred in 1993-1994 [51], hence this stand is referred to as the "Juvenile" site ( Figure 1b,c). ...
Humid boreal forests are unique environments characterized by a cold climate, abundant
precipitation, and high evapotranspiration. Transpiration (ET), as a component of
evapotranspiration (E), behaves differently under wet and dry canopy conditions, yet very few studies have focused on the dynamics of transpiration to evapotranspiration ratio (ET/E) under transient canopy wetness states. This study presents field measurements of ET/E at the Montmorency Forest, Québec, Canada: a balsam fir boreal forest that receives 1600 mm of precipitation annually (continental subarctic climate; Köppen classification subtype Dfc). Half-hourly observations of E and ET were obtained over two growing seasons using eddy-covariance and sap flow (Granier’s constant thermal dissipation) methods, respectively, under wet and dry canopy conditions. A series of calibration
experiments were performed for sap flow, resulting in species-specific calibration coefficients that increased estimates of sap flux density by 34% +/- 8%, compared to Granier’s original coefficients. The uncertainties associated with the scaling of sap flow measurements to stand ET, especially circumferential and spatial variations, were also quantified. From 30 wetting–drying events recorded during the measurement period in summer 2018, variations in ET/E were analyzed under different stages of canopy wetness. A combination of low evaporative demand and the presence of water on the canopy from the rainfall led to small ET/E. During two growing seasons, the average ET/E ranged from 35% +/- 2% to 47% +/- 3%. The change in total precipitation was not the main driver of seasonal ET/E variation, therefore it is important to analyze the impact of rainfall at half-hourly intervals.
... 80 km north of Québec City, Canada (BF1993 and BF2003 in Fig. 1c), part of the balsam fir -white birch bioclimatic domain. Specifically, two flux towers were installed in the "Bassin Expérimental du Ruisseau des Eaux-Volées" (BEREV) (Lavigne, 2007;Tremblay et al., 2008Tremblay et al., , 2009Nöel et al., 2014;Isabelle et al., 2018a). This experimental watershed lies at a mean altitude of 750 m above mean sea level (AMSL) with peaks at 1000 m AMSL. ...
... The vegetation of both catchments consists mostly of balsam fir (Abies balsamea (L.) Mill) along white birch (Betula papyrifera Marsh) and white spruce (Picea glauca (Moench) Voss) (Lavigne, 2007;Tremblay et al., 2008Tremblay et al., , 2009. Trees reach heights between 4 and 8 m in the sub-catchment A, the product of natural regeneration after the logging of 85% of the trees in 1993. ...
The boreal forest will be strongly affected by climate change and in turn, these vast ecosystems may significantly impact global climatology and hydrology due to their exchanges of carbon and water with the atmosphere. It is now crucial to understand the intricate relationships between precipitation and evapotranspiration in these environments, particularly in less-studied locations characterized by a cold and humid climate. This study
presents state-of-the-art measurements of energy and water budgets components over three years (2016–2018) at the Montmorency Forest, Québec, Canada: a balsam fir boreal forest that receives ∼1600mm of precipitation annually (continental subarctic climate; Köppen classification subtype Dfc). Precipitation, evapotranspiration and potential evapotranspiration at the site are compared with observations from thirteen experimental sites around the world. These intercomparison sites (89 study-years) encompass various types of climate and vegetation (black spruces, jack pines, etc.) encountered in boreal forests worldwide. The Montmorency Forest stands out by receiving the largest amount of precipitation. Across all sites, water availability seems to be the principal evapotranspiration constraint, as precipitation tends to be more influential than potential evapotranspiration and other factors. This leads to the Montmorency Forest generating the largest amount of evapotranspiration, on average ∼550mm y−1. This value appears to be an ecosystem maximum for evapotranspiration, which may be explained either by a physiological limit or a limited energy availability due to the presence of cloud cover. The
Montmorency Forest water budget evacuates the precipitation excess mostly by watershed discharges, at an average rate of ∼1050mm y−1, with peaks during the spring freshet. This behaviour, typical of mountainous headwater basins, necessarily influence downstream hydrological regimes to a large extent. This study provides a much needed insight in the hydrological regimes of a humid boreal-forested mountainous watershed, a type of
basin rarely studied with precise energy and water budgets before.
... Two flux towers have been deployed in the BEREV since late 2015 (Isabelle et al., 2020): the Juvenile tower in sub-basin 7a and the Sapling tower in the nearby sub-basin 7 (Fig. 2). Vegetation around the flux towers consists primarily of balsam fir (Abies balsamea (L.) Mill.) with scattered occurrences of white birch (Betula papyrifera Marsh), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana Mill.) (Tremblay et al., 2008(Tremblay et al., , 2009. Between 1993 and 1994, 85 % of sub-basin 7a was clear-cut (Guillemette et al., 2005), and regeneration created a forest stand that is homogenous in age. ...
High latitude regions, including the circumpolar boreal biome, are experiencing important changes in the availability of usable surface water because of climate change. In this context, an adequate representation of the land-atmosphere interaction is critical to ensure optimal management of current and future water resources, forest management, and climate prediction. However, the task is particularly intricate in high-latitude boreal forest, as land surface model faces several challenges due to the unique environmental conditions and ecological characteristics. The objective of this study is to quantify the impact of forest landscape heterogeneity, specifically stand leaf-area index (LAI), soil texture, and drainage regime, on surface water and energy balance in a small boreal high-latitude sub-catchment. To this end, hydrometeorological conditions at seventeen 20×20 m plots in a 1-km 2 boreal forest sub-basin are simulated using the Canadian Land Surface Scheme (CLASS), a land surface model, at the point scale. The subplot-scale soil texture, drainage regime, and vegetation characteristics and type are based as closely as possible on field measurements and observations for the 17 plots. The model-driven experiment comprises two sets of simulations using CLASS, each employing the same model setup and run for the 17 experimental plots. The main set employs meteorological forcing from a local micrometeorological tower within the sub-basin to investigate the plot-to-plot variability of albedo, energy fluxes, and soil state variables. A second set of simulations is conducted using meteorological forcing from the ERA5-Land reanalysis, which spans from 1986 to 2022. This data provides a longer time series, enabling a more accurate representation of the interannual climatic variability in the sub-basin. The results of the main and secondary sets of CLASS simulations are used to assess the plot-to-plot and temporal variability of several key hydrometeorological variables by calculating a monthly spread. In brief, the following conclusions and broader implications can be drawn from the findings: i) The simulated total annual evapotranspiration remains relatively uniform between plots despite notable variation in its partitioning from plot to plot. ii) In the presence of a full snowpack, the albedo exhibits substantial heterogeneity at the subplot scale, linked to the canopy's LAI. iii) Local soil properties, drainage regime, and vegetation structure and type exhibit substantial influence on the plot-to-plot variability in soil water content. iv) When parameterized with localized observations and measurements, CLASS can represent and be responsive to the complex dynamics of energy and water fluxes at the plot scale within the heterogeneous surface of boreal forests.
... While earlier studies in the Lac Laflamme carried out modelling of snow accumulation and melt (Barry et al., 1990;Plamondon et al., 1984;Prévost et al., 1991), more recent studies focused on analyzing changes in soil water content and temperature (D'Orangeville et al., 2016;Houle et al., 2012) and also nutrient cycling . In the BEREV, earlier studies explored the impacts of forest harvesting on hydrological behaviour (Guillemette et al., 2005;Lavigne, 2007;Tremblay et al., 2008) and water quality (Tremblay et al., 2009), while more recent studies performed plot scale studies to examine catch efficiency of snowfall gauges (Pierre et al., 2019), energy and water budget , evapotranspiration (Hadiwijaya et al., 2020) and groundwater flow (Schilling et al., 2021). ...
Hydrological conditions in cold regions have been shown to be sensitive to climate change. However, a detailed understanding of how regional climate and basin landscape conditions independently influence the current hydrology and its climate sensitivity is currently lacking. This study, therefore, compares the climate sensitivity of the hydrology of two basins with contrasted landscape and meteorological characteristics typical of eastern Canada: a forested boreal climate basin (Montmorency) versus an agricultural hemiboreal basin (Acadie). The physically based Cold Regions Hydrological Modelling (CRHM) platform was used to simulate the current and future hydrological processes. Both basin landscape and regional climate drove differences in hydrological sensitivities to climate change. Projected peak SWE were highly sensitive to warming, particularly for milder baseline climate conditions and moderately influenced by differences in landscape conditions. Landscape conditions mediated a wide range of differing hydrological processes and streamflow responses to climate change. The effective precipitation was more sensitive to warming in the forested basin than in the agricultural one, due to reductions in forest canopy interception losses with warming. Under current conditions, precipitation and discharge were found to be more synchronized in the greater relief and slopes of the forested basin, whereas under climate change, they are more synchronized in the agricultural basin due to reduced infiltration and storage capacities. Flow through and over agricultural soils translated the increase in water availability under a warmer and wetter climate into higher peak discharges, whereas the porous forest soils dampened the response of peak discharge to increased available water. These findings help diagnose the mechanisms controlling hydrological response to climate change in cold regions forested and agricultural basins.
... These field observations aim to investigate the impacts of forest harvesting or regeneration on soil erosion, snowmelt rate and timing, evapotranspiration, sublimation, snow accumulation, and streamflow (Buttle et al., 2009), and fields are mainly established in Alberta (Granger and Pomeroy, 1997), Saskatchewan (Stewart et al., 1998), Yukon (Rasouli et al., 2019), Northwest Territories (Spence and Hedstrom, 2021), and Ontario (Webster et al., 2021). In addition to GEWEX and BOREAS, some work has also been conducted in the boreal forests in Quebec (Tremblay et al., 2008;Plamondon and Ouellet, 1980). By comparing hydrological processes in clear-cut, regeneration, and openings, it is found that harvesting consistently increases peak flows and annual streamflow (Buttle et al., 2009;Guillemette et al., 2005), which is consistent with PWE findings. ...
Boreal forests cover about one-third of the global forested area and are under rapid alteration due to increased natural and human-induced forest disturbance, which have important impacts on forest carbon cycling, hydrology, biodiversity, and many other ecological characteristics, processes, and functions. In this review, we focus on how forest harvesting affects hydrological processes in boreal forests within the context of increased and cumulative forest disturbance across various spatial scales. At the stand level, harvesting affects snow processes (i.e., snow interception, snow water equivalent, ablation, and snowmelt), decreases evapotranspiration (ET) and water use efficiency (WUE), and has negative impacts on soil dynamics (i.e., infiltration and soil moisture). These hydrological changes at the stand level can be counteractive or additive, cumulatively leading to more varied effects at larger spatial scales. In small watersheds, spring freshets (or high flows) are consistently increased following harvesting, while annual streamflow is often increased but some contradictory results are found in Siberia, Russia. These varied responses are likely dependent upon differences in energy budgets, climate, post-disturbance vegetation trajectories, and their dynamic interactions over space and time. For larger watersheds and regions, cumulative forest disturbance interacts with climate, leading to more complicated and varied hydrological responses. Forest management implications and future research topics are also suggested.
... L'effet sur l'hydrologie des bassins versants endommagés est relativement bien documenté dans la littérature. La disparition des arbres adultes par chablis ou coupe entraîne une aggravation des pics de crue aux exutoires des bassins versants endommagés à plus de 30% (Beschta et al., 2000 ;Tremblay et al., 2008). La comparaison de bassins versants forestiers affectés de façon contrastée par le cyclone Lothar en Suisse montre une augmentation de 60% de l'écoulement à l'exutoire l'année suivante (Badoux et al., 2006). ...
Colloque du 30 juin 2009 : Sylviculture, forêts et tempêtes
... The region is monitored with a configuration of gauging stations on 21 catchments, offering a long-term regional synoptic view of tributaries that flow mostly north-south, and including six nested catchments ranging from 1 to 1140 km 2 in the Montmorency River catchment (Tremblay et al., 2008) (Table 1). Codes are composed of initial letters of the full names and surface areas (km 2 ). ...
... Peak flow after 49% clear-cutting in a watershed did not change during 30 years of monitoring (Duncan, 1986). Tremblay et al. (2008) showed that no significant increases in peak flow or bankfull discharge occurred except during extremely heavy rainfall. Peak flow reduction after harvesting was associated with increased soil pore space that forced a slower flow path in the soil matrix (Cheng, 1989). ...
We evaluated the effects of 50% strip thinning on peak flow responses in 17-ha nested catchments. We observed 117 storm events from April 2010 to December 2013, including 32 events in the pre-thinning period, 15 events during the thinning operation, and 70 events in the post-thinning period. Paired-catchment analysis with multiple pairs of nested gauging stations revealed that changes in peak flow responses varied depending on the location of the nested observation stations. Increases in peak flow during the operation period were only significant in gauging stations located at the outlet and the middle of a catchment. Increases in peak flow during the post-treatment period became significant in all nested catchments, but not in the catchment outlet. Rates of increase in peak flow ranged from 17.7% to 44.4%, which is within the range of previous studies. Different responses for changes in peak flow among nested pairs were associated with changes in internal hydrological flow pathways due to removal of timber and hydrological connectivity via overland flow generated by newly installed and reactivated skid trails. Our findings suggest that the effects of timber harvesting on peak flow are scale-dependent with respect to drainage areas, hydrological links, and management practices. Selection of gauging locations and process-based observations within catchments are essential for testing hypotheses related to the effects of timber harvesting with robust hydrological monitoring.
... The relatively large peak flow response, when compared to 50 other similar studies globally, was attributed to increased 117°43=W 1860-1971 ha 1966-2000 1966-1993 1994 1977-2002 111°59=W 189-5669 ha 1994-1998 1994-1995 1996-1997 1998 92°10=W 70-194 ha 1990-1999 1990-1995 1996 & 1998 1999 1967-1998 1967-1974; 1985-1992 1974-1975; 1993 1976-1978; 1994-1998 1974-1976 1993-1997 1993 1994-1996 1996-1997 1994 (Guillemette et al. 2005). Another REVEW study compared harvesting 50% of four small basins (<50 ha) with harvested areas distributed at different distances from the stream and found that the configuration of the harvests had little effect on peak flows (Tremblay et al. 2008). A study of larger basins (400 to 11 900 ha) in the boreal forest of northeastern Ontario, with uplands dominated by black and white spruce with minor occurrence of balsam fir, jack pine, white birch, and trembling aspen, and lowland areas dominated by tamarack and black spruce, where the proportion of the basins harvested varied from 5% to 25%, reported no definitive effects on annual runoff or peak flow timing or magnitude (Buttle and Metcalfe 2000). ...
Industrial development within Canada’s boreal zone has increased in recent decades. Forest management activities, pulp and paper operations, electric power generation, mining, conventional oil and gas extraction, nonconventional oil sand development, and peat mining occur throughout the boreal zone with varying impacts on water resources. We review impacts of these industries on surface water, groundwater, and wetlands recognizing that heterogeneity in the dominance of different hydrologic processes (i.e., precipitation, evapotranspiration, groundwater recharge, and runoff generation) across the boreal zone influences the degree of impacts on water resources. Through the application of best management practices, forest certification programs, and science-based guidelines, timber, pulp and paper, and peat industries have reduced their impacts on water resources, although uncertainties remain about long-term recovery following disturbance. Hydroelectric power developments have moved toward reducing reservoir size and creating more natural flow regimes, although impacts of aging infrastructure and dam decommissioning is largely unknown. Mineral and metal mining industries have improved regulation and practices, but the legacy of abandoned mines across the boreal zone still presents an ongoing risk to water resources. Oil and gas industries, including non-conventional resources such as oil sands, is one of the largest industrial users of water and, while significant progress has been made in reducing water use, more work is needed to ensure the protection of water resources. All industries contribute to atmospheric deposition of pollutants that may eventually be released to downstream waters. Although most industrial sectors strive to improve their environmental performance with regards to water resources, disruptions to natural flow regimes and risks of degraded water quality exist at local to regional scales in the boreal zone. Addressing the emerging challenge of managing the expanding, intensifying, and cumulative effects of industries in conjunction with other stressors, such as climate change and atmospheric pollution, across the landscape will aid in preserving Canada’s rich endowment of water resources.
... El aumento de caudal es proporcional al porcentaje de la superficie de la cuenca que se interviene (Hibbert 1967), aun cuando el efecto debido a cambios en la cubierta de bosques que comprometen menos del 15 -20 % de la superficie de la cuenca no puede ser detectado por las mediciones en los caudales (Bosch y Hewlett 1982, Stednick 1996, MacDonald y Stednick 2003. El efecto es mayor en cosechas a tala rasa que en cortas parciales (Rothacher 1970, Fahey 1994, Brown et al. 2005, Tremblay et al. 2008, es más apreciable en regiones con climas más húmedos (Keppeler 1998, Keenan et al. 2004) y es más notorio en cuencas pequeñas que en grandes (Calder 2007). ...
Se estudiaron los efectos hidrológicos de la cosecha a tala rasa y posterior reforestación en una cuenca de 34,4 ha localizada en una zona con clima templado lluvioso del sur de Chile. Se analizaron los caudales mensuales, anuales, de verano y los caudales máximos comparando las condiciones de pre y postcosecha. Durante los primeros cuatro años de la cosecha se observó un importante aumento de los caudales anuales, pero luego de 8 años de desarrollo de la nueva plantación se está notando una declinación hacia los niveles de precosecha. Los caudales de verano aumentaron luego de la cosecha, situación que se mantuvo hasta seis años después de la intervención, pero a partir del séptimo verano la cuenca muestra caudales de estío similares a los de la condición de precosecha. Los caudales máximos también aumentaron luego de la cosecha, aun cuando el incremento se notó más en tormentas de menor magnitud. Aunque el aumento de caudales se ha mantenido luego de ocho años de la intervención, los caudales máximos de las condiciones de pre y postcosecha para la cuenca estudiada sólo serían diferentes para eventos con períodos de retorno inferiores a 10 años.
... The effect of management may not be neglected. Forest clearing generally leads to an increase in runoff (Badoux, 2006;Tremblay, 2008). In young forest plantations, the drainage flux can be doubled and evapotranspiration reduced by 50% as compared with older stands (Stella et al., 2009). ...
Linking water and carbon cycles and their interactions will be a key issue in the future to understand the ecological processes. Very few studies quantify the feedback effects of the two cycles based on long time series measurements, in order to understand the effect of climatic change and the impact of extreme climatic events such as storms. Our project aims to implement and calibrate a coupled eco-hydrological approach over two watersheds to estimate the effects of land cover changes, extreme climatic events, climatic changes and forest management on the water and carbon budgets for the last decades. The study is carried out over two watersheds (Tagon and Bouron) of Les Landes forest located in the South Western region of France. These two watersheds are comparable in terms of land cover: close to 90% of planted and managed coniferous forest. They have been alternatively damaged by the two successive Martin (Dec. 1999) and Klaus (Jan. 2009) winter storms, Tagon being more damaged by the former and Bouron by the latter. The water runoff, water table depth and climate of the two watersheds have been monitored since 1967 at the earliest. For each watershed, land cover maps, including detailed information of the pine forest's age structure, was obtained from 1984 to 2008 using satellite information, ground truth and statistics of the national inventory. In 1999, 36 % of the stands of the Tagon watershed where affected by the storm at levels of more than 20% of fallen trees, having for consequences to drastically change the age distribution of pine forest stands within the watershed. In 2007, 70 % of its surface is still occupied by stands younger than 21 years, which can be linked with the increase in runoff after 1999 (decreased rainfall interception and tree canopy transpiration. These higher peak flows decrease with time (progressive recovery of the vegetation) but are still visible after four years.
... There is one qualification to the above analysis. Several studies have been carried out in recent years regarding the impact of deforestation on streamflow (Schilling et al., 2008;Lin and Wei, 2008;Zheng et al., 2008;Guo et al., 2008;Juckem et al., 2008;Tremblay et al., 2008;Zhang et al., 2008). Matheussen et al. (2000) used hydrologic models to argue that deforestation has increased annual mean flow at The Dalles by $2% through a reduction in evapotranspiration, at the same time accelerating the freshet. ...
Most hydrologic trends result from a combination of climatic and human influences, and analyses of hydrologic changes often do not differentiate these factors, despite the obvious relevance of this distinction. Here, we separate human and climate influences on the Columbia River hydrologic cycle and sediment discharge on the basis of robust data analyses since 1858. Human influences include water withdrawal for irrigation, flow regulation, reservoir manipulation, mining and deforestation. The Columbia’s streamflow and sediment discharge are strongly correlated with large-scale climate patterns, particularly the ENSO (El Niño Southern Oscillation) and PDO (Pacific Decadal Oscillation). The mean annual Columbia River virgin flow at The Dalles has decreased ∼16.5%, 8–9% due to climate change and 7–8% due to water withdrawal for irrigation. Climate impacts on the sediment discharge are larger than on streamflow because sediment discharge increases more than linearly with flow. Total sediment and sand transports have decreased >50% and >70% respectively, only a fraction of which is due to climate change. Changes in the timing of maximum flows from sub-basins, as influenced by flow regulation and irrigation withdrawal, determine freshet timing and play a larger role in determining the maximum flow and sediment transport levels. Flow regulation (since 1970) has decreased peak spring flows by ∼45% and increased flow during the rest of the year. The spring freshet flow decrease due to climate change is 11%; the decreases due to water withdrawal and flow regulation are about 12% and 26% respectively. The peak freshet flow now typically occurs 2–4 weeks earlier than before 1900.
Despite the wide application of riparian buffers in the managed boreal forest, their long-term effectiveness as freshwater protection tools remains unknown. Here, we evaluate windthrow incidence in riparian buffers in the eastern Canadian boreal forest and determine the effect of windthrow on the water quality index of the adjacent freshwater ecosystems. We studied 40 sites—20 riparian buffers, aged 10 to 20 years after harvesting and 20 control sites within intact riparian environments—distributed among clay and sandy (esker) soils and black spruce (Picea mariana) and jack pine (Pinus banksiana) stands. We observed more windthrow in the harvested stands (36%) relative to the control sites (16%), regardless of substrate and species. We determined that the most important factors explaining windthrow were exposition, harvesting, aquatic environment size, and stand characteristics. These factors drive wind exposure, speed, and force, which determine post-harvest windthrow risk. Furthermore, windthrow negatively affected the water quality index of the adjacent aquatic systems, i.e., greater windthrow decreased the protective effect of the riparian buffer. We recommend increasing the use of partial harvest near riparian environments and adapting riparian buffers to site conditions to ensure the long-term protection of adjacent freshwater ecosystems.
Oksana Y. Oshurkevych-Pankivska, and Yuriy I. Pankivskyi (2022). The Flow Regulatory Influence of Forests on The Catchments of Small Rivers of Ukrainian Beskids. In: "Environmental Science, Technology, Engineering and Mathematics (STEM)", Lawrence K. Wang Mu-Hao Sung Wang and Yuriy I. Pankivskyi (editors). Volume 2022, Number 11, November 2022, 190 pages, Lenox Institute Press, Massachusetts, USA. ISBN 978-0-9890870-3-2. https://doi.org/10.17613/j4fz-z124 .... ABSTRACT: Beskids are the part of the Ukrainian Carpathian Mountains. The current work is devoted to quantitative estimation of the flow regulating role of Beskid forests and its’ change under anthropogenic load on the basis of analysis of forest-hydrological indices and experimental investigation. The following have been accomplished: (a) The method of the past forest exploitation on the Beskid catchments has been defined; (b) The forestry enterprises structural units positioning with regard to the boundaries of catchments of various orders have been analyzed; (c) The forest inventory characteristics on these river catchments have been studied; (d) The precipitation flow regulation depending on forest land percentage and area of the catchments and forest flow regulation influence on flood and snow melt flood discharge formation have been evaluated; (e) The final harvesting influence on the water-physical properties of soils and the flow redistribution has been determined; and (f) The functional dependence of the hydrological indices versus catchments’ characteristics with employment of mathematical modeling methods has been established. The obtained in current work results assists to elaborate methods of flow regulating capability of forest ecosystems and foresee prospect of the forest harvesting operations planning with preservation of flow regulating influence of forests. The results of estimation of the forest influence on flood and snow-melt flood discharges should be taken into account in design of the flood protection facilities and flow regulating reservoirs on the territory of Beskids.
One of the roles of Land Surface Models (LSMs) is to partition evapotranspiration (E) into overstory transpiration (E_T), understory evapotranspiration (E_G), and wet canopy evaporation (E_C). Unfortunately, only a handful of studies have evaluated the performance of LSMs with E partitioning. Unlike dry canopies which are dominated by transpiration, wet canopies lead to the evaporation of intercepted water. In this respect, there is no better testing site for LSMs than the humid boreal forest, which is characterized by frequent precipitation and sustained evapotranspiration. This study assesses the performance of the Canadian Land Surface Scheme (CLASS) in simulating evapotranspiration and its components by applying detailed observations of water pathways and residence times in a forest canopy using a variety of methods (eddy covariance; sap flow, throughfall and stemflow measurements; and the stem compression approach). The study site was located in Montmorency Forest in Québec, Canada, a balsam fir boreal forest with ~1600 mm of annual precipitation. The field campaign was conducted during the summers of 2017 and 2018. To improve the accuracy of the simulations, we adjusted the definition of maximum canopy water storage, S = c x LAI by using c = 0.49 mm instead of the default value of 0.20 mm. This simple modification improved the performance of CLASS when simulating components of evapotranspiration, indicated by the increase in the modified Kling-Gupta efficiency (KGE') with rises between 0.01 and 0.23. Overall, CLASS performed well in simulating evapotranspiration and overstory transpiration in dry canopy conditions at half-hourly time steps with KGE' values between 0.67 and 0.81. The contribution of simulated E_T, E_G and E_C to total E during the two sampling periods were 46%, 24% and 30% respectively, which were comparable with the field observations (35%, 22% and 25%, respectively). In conclusion, CLASS was able to simulate E partitioning in dry and wet canopy conditions reasonably well at both seasonal and half-hourly time scales.
Maps of ecosystem services are becoming increasingly useful for reporting on the potential impacts of human activity on the environment. However, interactions in watersheds are complex, and mapping hydrological ecosystem services (HES) requires indicators which accurately measure underlying processes. The main objective of this study was to take advantage of the Soil and Water Assessment Tool (SWAT) and Light detection and ranging (LiDAR) data to map the erosion regulation service for a managed boreal forest watershed. To do so, SWAT and partial least-squares (PLS) regression were used to select explanatory variables for sediment yield. Variables of importance in projection (VIP) with a score > 1 were selected to develop LiDAR-based ecological indicators. Four categories of variables were identified as VIP from the PLS: i) climate: annual precipitation, ii) land use: forest, cutovers; iii) land use patterns: cutover patch cohesion index, and iv) morphometric: main channel length, channel length and sub–watershed area. The height of the 95th percentile of LiDAR returns (p95) < 5m provided the most accurate spatial representation of cutovers and the optimal cutover patch cohesion index. Other morphometrics were obtained from a LiDAR-based digital terrain model. Explanatory variables for sediment yield were combined in a sediment erosion control (SEC) index, except for yearly average precipitation because the SEC index is not actually used as a temporal index. As expected, a negative relationship was found between sediment yield and SEC index rankings for the 2006-2015 period (Spearman, rho = -0.6, p < 0.05). Moreover, the overall agreement between SWAT and SEC index classes was 87% for 31 sub–watersheds. The study provides a list of relevant explanatory variables for modelling sediment yield in a boreal forest watershed where timber harvest activities occur. It also demonstrates the use of LiDAR data for deriving an index of the erosion regulation ecosystem service in a proxy–based approach as has not been demonstrated previously at the watershed level. The validation method applied here fills a gap on ecosystem services mapping that could benefit studies in other watershed contexts.
Two-wavelength scintillometer systems can provide much needed measurements of area-averaged sensible and latent heat fluxes. However, these devices rarely have been deployed on canopy-covered complex terrain, and never in the circumpolar boreal biome, where large-scale fluxes are essential to hydroclimate modellers. We present a comparison of fluxes measured above a boreal-forested valley with a two-wavelength scintillometer and an eddy covariance system. Instruments were deployed in late summer 2017, and 19 days of data were retained for the analysis. The scintillometer path was 1347-m long and projected across the valley between 5 and 100 m above the ground, with an effective height of ≈88 m. The limitations of deriving surface fluxes using scintillometry in complex terrain are discussed, and the effects of atmospheric conditions on the flux comparison are quantified. Fluxes are calculated with the scintillometer only, and using a number of atmospheric variables from the eddy-covariance system; impacts of these calculation methods on the correlation between instrumental systems are assessed. Despite a weak agreement of structure parameters between instruments, the comparison of scintillometer and eddy-covariance fluxes yields good correlation (R2 up to 0.82). Scintillometry correlates best with eddy-covariance data when the atmospheric surface-layer top is above the scintillometer effective height, but R2 only drops slightly otherwise (average decrease of 0.11). The validity of scintillometer fluxes appears dubious during night-time and stable periods. We show that area-averaged flux measurements using two-wavelength scintillometers are possible in hilly forests, but more studies are needed to pinpoint the best methodological framework.
Le bassin versant de la rivière Bonaventure (QC, Canada) est soumis
à une exploitation forestière soutenue depuis plus d’un siècle. Son couvert
forestier a également été considérablement affecté par les perturbations
naturelles, notamment par un incendie en 1995 qui a couvert 12% de la
superficie du bassin versant. L’histoire récente du couvert forestier du bassin
versant de la rivière Bonaventure fait donc de ce dernier un laboratoire
idéal pour y étudier la réponse hydrogéomorphologique des cours d’eau
à l’altération du couvert forestier. Ainsi, quatre tronçons de cours d’eau
dynamiques et soumis à des surfaces déforestées d’ampleur différentes ont
été sélectionnés au sein du bassin versant de la rivière Bonaventure. Trois
d’entre eux sont situés sur des tributaires de la rivière tandis que le dernier
est situé en aval des trois premiers, sur la rivière Bonaventure. L’objectif de
l’étude est d’analyser et de comparer la sensibilité hydrogéomorphologique
des quatre tronçons, en réponse à l’altération du couvert forestier au sein
du bassin versant de la rivière Bonaventure.
Pour cela, l’impact des interventions et perturbations forestières a été
quantifié en calculant l’évolution annuelle de l’aire équivalente de coupe
(AEC) au sein de l’aire de drainage associée à chaque tronçon, depuis
des données vectorielles de déforestation couvrant une période de 39 ans
(1976-2015). Puis la trajectoire géomorphologique de chacun des tronçons
a été dressée à partir de photographies aériennes couvrant une période de
53 ans (1963-2016). Cinq variables morphométriques et sédimentaires ont
ainsi été extraites : la largeur du lit actif, l’indice de tressage, l’indice de
sinuosité, le taux de migration latérale et la superficie des bancs d’accumulation.
Enfin, des séries temporelles hydrologiques associées à la rivière
Bonaventure et couvrant une période de 52 ans (1965-2017) ont été explorées,
ainsi que des séries temporelles climatiques concernant les données de
précipitations et de température relevées à Gaspé (QC, Canada) de 1948 à
2010. La sensibilité hydogéomorphologique des tronçons est alors analysée
et comparée, en réponse à l’altération du couvert forestier et aux variables
hydro-climatiques.
Il en ressort que les variables hydro-climatiques ont une influence bien
plus importante sur la dynamique hydrogéomorphologique, comparativement
à l’altération du couvert forestier. Par extension, il est complexe
d’évaluer dans quelle mesure l’altération du couvert forestier contrôle la dynamique
hydrogéomorphologique des tronçons étudiés. Cependant, l’étude
a permis de mettre en évidence une réponse géomorphologique marquée à
l’incendie de 1995. Cette réponse à une altération soudaine et importante
du couvert forestier permet de confirmer le rôle du couvert forestier en
tant que facteur de contrôle, tout en laissant supposer une faible sensibilité
hydrogéomorphologique des tronçons à l’altération du couvert forestier,
lorsque l’altération est modérée à l’échelle des aires de drainage respectives
des tronçons.
The relationship between peak specific discharge and watershed area is examined for large, rare and extreme floods in Malaysia using a distributed hydrological model. Envelope curves for specific discharge for these events and the uncertainty is quantified. The relationships between rainfall duration and intensity as a function of watershed size were also examined. As a result, three main regions were defined to estimate the peak discharge as a function of watershed size for large, extreme and rare floods. The average magnitudes for the PMP and the world’s extreme rainfall events were 5 and 12 times larger than the 100-year event, respectively. The envelope curves may assist engineers and other interested parties to estimate the peak discharge for watershed up to 100,000 km², especially for ungauged watersheds.
The hydrological effects of plantation clearcutting and reforestation were studied in a 34.4 ha experimental catchment localized in an area with rainy temperate climate in southern Chile. Monthly, annual and summer runoffs and peakflows were analyzed comparing the pre and post-harvesting conditions. During the first four years after clearcutting an important increase in annual runoff was observed, but after eight years of development of the new plantation a recovery towards pre-harvesting levels is being noticed. Summer runoffs also increased after plantation harvesting and the effect was still noticeable six years after the forest operation, but since the seventh summer period low flows became similar to those from the pre-harvesting condition. Peakflows also increased after clearcutting but the effect was higher in low magnitude rain storms. Although this increase is still noticeable eight years after the intervention, peakflows from the pre and post-harvesting conditions in the study catchment would only differ for events with return periods lower than 10 years.
Summer stream water quality was monitored before and following the logging of 50% of the boreal forest within three small watersheds (<50 ha) nested in the 'Ruisseau des Eaux-Volées' Experimental Watershed, Montmorency Forest (Québec, Canada). Logging was conducted in winter, on snow cover according to recommended best management practices (BMPs) to minimize soil disturbance and protect advance growth. A 20-m forest buffer was maintained along perennial streams. In watershed 7.2, cut-blocks were located near the stream network and logging was partially allowed within the riparian buffer zone. In watersheds 7.5 and 7.7, logging occurred farther away from the stream network. Observations were also made for watershed 7.3 that collected the runoff from watersheds 7.2 and 7.5, and watershed 7.6, the uproad portion of watershed 7.7. The control watershed 0.2 was contiguous to the impacted watersheds and remained undisturbed. Following clearcutting, changes in summer daily maximum and minimum stream temperatures remained within ±1 °C while changes in diurnal variation did not decrease by more than 0.5 °C. Concentrations of NO3- greatly increased by up to 6000% and concentrations of K+ increased by up to 300% during the second summer after logging. Smaller increases were observed for Fetotal (up to 71%), specific conductance (up to 26%), and Mg2+ (up to 19%). Post-logging pH decreased slightly by no more than 7% while PO43- concentration remained relatively constant. Suspended sediment concentrations appeared to increase during post-logging, but there was not enough pre-logging data to statistically confirm this result. Logging of moderate intensity and respecting established BMPs may account for the limited changes of water quality parameters and the low exceedances of the criteria for the protection of aquatic life. The proximity of the cutover to the stream network and logging within the riparian zone did not appear to affect water quality.
It is generally believed that roots have an effect on infiltration. In this study we analysed the influence of tree roots from Norway spruce (Picea abies (L.) Karst), silver fir (Abies alba Miller) and European beech (Fagus sylvatica L.) on preferential infiltration in stagnic soils in the northern pre-Alps in Switzerland. We conducted irrigation experiments (1 m2) and recorded water content variations with time domain reflectrometry (TDR). A rivulet approach was applied to characterise preferential infiltration. Roots were sampled down to a depth of 0.5 to 1 m at the same position where the TDR-probes had been inserted and digitally measured. The basic properties of preferential infiltration, film thickness of mobile water and the contact length between soil and mobile water in the horizontal plane are closely related to fine root densities. An increase in root density resulted in an increase in contact length, but a decrease in film thickness. We modelled water content waves based on fine root densities and identified a range of root densities that lead to a maximum volume flux density and infiltration capacity. These findings provide convincing evidence that tree roots improve soil structure and thus infiltration.
This study quantified long-term changes in streamflows associated with clear-cutting and road construction and examined alternative hydrologic mechanisms to explain stream hydrograph changes in the Cascades Range, western Oregon. We examined differences in paired peak discharges for 150 to 375 storm events for five basin pairs, using 34-year records from two pairs of 60-to-101-ha experimental basins in the H. J. Andrews Experimental Forest, and 50-to-55-year records from three pairs of adjacent basins ranging from 60 to 600 km2. Forest harvesting has increased peak discharges by as much as 50% in small basins and 100% in large basins over the past 50 years. These increases are attributable to changes both in flow routing due to roads and in water balance due to treatment effects and vegetation succession.
We outline a view of how road networks interact with stream networks at the landscape scale and, based on examples from recent and current research, illustrate how these interactions might affect biological and ecological processes in stream and riparian systems. At the landscape scale, certain definable geometric interactions involving peak flows ( floods) and debris flows (rapid movements of soil, sediment, and large wood down steep stream channels) are influenced by the arrangement of the road network relative to the stream network. Although disturbance patches are created by peak-flow and debris-flow disturbances in mountain landscapes without roads, roads can alter the landscape distributions of the starting and stopping points of debris flows, and they can alter the balance between the intensity of flood peaks and the stream network's resistance to change. We examined this conceptual model of interactions between road networks and stream networks based on observations from a number of studies in the H. J. Andrews Experimental Forest, Oregon (U.S.A.). Road networks appear to affect floods and debris flows and thus modify disturbance patch dynamics in stream and riparian networks in mountain landscapes. We speculate that these changes may influence the rates and patterns of survival and recovery of disturbed patches in stream networks, affecting ecosystem resilience, and we outline an approach for detecting such effects based on a patch dynamics perspective. A field sampling scheme for detecting the magnitude of various road effects on stream and riparian ecology could involve (1) landscape stratification of inherent stream network susceptibility to floods or debris flows, (2) overlay of road and stream networks and creation of areas with various densities of road-stream crossings, emphasizing midslope road-stream crossings, and (3) designations of expected high- and low-impact stream segments based on numbers of upstream road-stream crossings where sampling of selected biological variables would be conducted.
Resumen: Desglozamos una perspectiva sobre la interacción entre redes carreteras y redes de arroyos a escala de paisaje e ilustramos como estas interacciones pueden afectar procesos biológicos y ecológicos en sistemas de arroyos y riparios en base a ejemplos que parten de investigaciones recientes y en proceso. A escala de paisaje, ciertas interacciones geométricas definibles y que involucran flujos-pico (inundaciones) y flujos de detritus (movimientos rápidos de suelo, sedimentos y piezas grandes de madera en canales con pendiente pronunciada) son influenciadas por los arreglos de la red de carreteras en relación con la red de arroyos. A pesar de que los parches de perturbación son creados por perturbaciones en los flujos-pico y en los flujos de detritus en paisajes montañosos sin carreteras, las carreteras pueden alterar las distribuciones de puntos de inicio y final de flujos de detritus en el paisaje y pueden alterar el balance entre la intensidad de los picos de inundación y la resistencia del arroyo al cambio. Examinamos este modelo conceptual de interacciones entre la red de arroyos y la red de carreteras en base a observaciones de una cantidad de estudios del Bosque Experimental Andrews, en Oregon. Las redes de carreteras aparentemente afectan las inundaciones y los flujos de detritus, esto modifica la dinámica de los parches de perturbación en redes de arroyos y zonas riparias de paisajes montañosos. Especulamos que estos cambios pueden influenciar las tasaa y patrones de supervivencia y recuperación de parches perturbados en redes de arroyos, afectando la resistencia del ecosistema y detallamos una aproximación para detectar estos efectos en base a una perspectiva de dinámica de parches. Un esquema de muestre de campo para detectar la magnitud de varios efectos de las carreteras en la ecología de arroyos y zonas riparias podría involucrar (1) la estratificación de la susceptibilidad inherente de la red de arroyos a inundaciones o flujo de detritus en el paisaje, (2) la sobreposición de redes de arroyos y carreteras y la creación de cruces a mitad de la pendientes, y (3) la designación de segmentos esperados de bajo y alto impacto donde se realicen muestreos de variables biológicas selectas en base a números de cruces entre arroyos y carreteras que se encuentren arroyo arriba.
Typescript (photocopy). Thesis (Ph. D.)--Oregon State University, 2001. Includes bibliographical references (leaves 212-224).
Size of annual peak flow in a small watershed in western Oregon was reduced 32%, and average delay of all peak flows was nearly 9 hours following clearcut logging. Size of annual peak flows caused by rain with snowmelt was reduced 36%, and peak flows resulting from rain with snowmelt were delayed an average of nearly 12 hours following logging. Changes are attributed mainly to differences in short-term accumulation and melting of snow. No significant changes were detected in size or timing of peak flows that resulted from rainfall alone.
Changes in water yield are summarized for experimental treatments performed on three gaged, forested watersheds at the Hubbard Brook Experimental Forest in New Hampshire. The treatments included clear-felling and herbicide applications performed on watershed 2 during 1965-1968, progressive strip-cutting performed on watershed 4 during 1970-1974, and whole-tree harvesting performed on watershed 5 during 1983-1984. Responses in annual water yield varied markedly among treatments. Clear-felling and 3 successive years of herbicide applications caused annual water yields to increase by an average of 288 mm, or 32%. The strip-cutting and whole-tree harvesting treatments caused maximum annual increases in water yield of 114 mm (8%), and 152 mm (23%), respectively. Most of the water yield increases occurred as augmentation to low flows during the growing season, although some peak flows were also increased. Volume of snowmelt runoff was relatively unaffected. increases in annual water yield diminished rapidly as forests regenerated and were undetectable within 7-9 years after treatment. Unexpected decreases in annual water yields occurred for years 13-30 after the clear-felling and herbicide treatment and for years 8-25 after the strip-cutting due to the regenerating forests having greater proportions of tree species with lower stomatal resistances.
In this paper, we conduct a reanalysis of methods and data used by Jones and Grant [1996]. Data from three small watersheds (60-101 ha) and three pairs of large basins (60-600 km2) in Oregon's western Cascades were used to evaluate effects of timber harvest and road construction on peak flows. We could not detect any effect of cutting on peak flows in one of the large basin pairs, and results were inconclusive in the other two large basin pairs. One small watershed was 100% clear-cut, a second was 31% patch-cut with 6% of the area affected by road construction, and a third was held as a long-term control. Peak flows were increased up to 90% for the smallest peak events on the clear-cut watershed and up to 40% for the smallest peak flows on the patch-cut and roaded watershed. Percentage treatment effects decreased as flow event size increased and were not detectable for flows with 2-year return intervals or greater on either treated watershed. Treatment effects decreased over time but were still found after 20 years on the clear-cut watershed but for only 10 years on the patch-cut and roaded watershed.
The effects of road building and selective tractor harvesting on storm runoff were assessed for a small (424 ha) coastal watershed in northern California. Road building alone did not significantly affect the storm runoff. After road building and logging, lag time was decreased approximately I.5 hours, and the very small storm volumes (less than 1209 m3) and storm peaks (less than 566 L/s) were increased by about 132 and 111% respectively. Storm volumes and peaks of large storms (occurring less frequently than eight times a year) were not significantly increased by either roads or logging. even though more than 15% of the watershed was compacted in roads, skid trails, and landings. Although a decrease in lag time showed that the average storm hydrograph was shifted forward in time. only the small storm hydrographs were changed in shape. We speculate that the rate of delivery of water to the stream channel during large channel-forming flows was governed by infiltration and subsurface flow rates on the 85% of the watershed that was unaffected by roads. landings. or skid trails. From these findings we conclude that, in a rain-dominated hydrologic environment. logging and forest road construction (as carried out in this study) are not likely to change the flow regime of a stream adversely.
The relative importance in geomorphic processes of extreme or catastrophic events and more frequent events of smaller magnitude can be measured in terms of (1) the relative amounts of "work" done on the landscape and (2) in terms of the formation of specific features of the landscape. For many processes, above the level of competence, the rate of movement of material can be expressed as a power function of some stress, as for example, shear stress. Because the frequency distributions of the magnitudes of many natural events, such as floods, rainfall, and wind speeds, approximate log-normal distributions, the product of frequency and rate, a measure of the work performed by events having different frequencies and magnitudes will attain a maximum. The frequency at which this maximum occurs provides a measure of the level at which the largest portion of the total work is accomplished. Analysis of records of sediment transported by rivers indicates that the largest portion of the total load is carried by flows which occur on the average once or twice each year. As the variability of the flow increases and hence as the size of the drainage basin decreases, a larger percentage of the total load is carried by less frequent flows. In many basins 90 per cent of the sediment is removed by storm discharges which recur at least once every five years. Transport of sand and dust by wind in general follows the same laws. The extreme velocities associated with infrequent events are compensated for by their rarity, and it is found that the greatest bulk of sediment is transported by more moderate events. Many rivers are competent to erode both bed and banks during moderate flows. Observations of natural channels suggest that the channel shape as well as the dimensions of meandering rivers appear to be associated with flows at or near the bankfull stage. The fact that the bankfull stage recurs on the average once every year or two years indicates that these features of many alluvial rivers are controlled by these more frequent flows rather than by the rarer events of catastrophic magnitude. Because the equilibrium form of wind-blown dunes and of wave-formed beaches is quite unstable, the frequency of the events responsible for their form is less clearly definable. However, dune form and orientation are determined by both wind velocity and frequency. Similarly, a hypothetical example suggests that beach slope oscillates about a mean value related in part to wave characteristics generated by winds of moderate speed. Where stresses generated by frequent events are incompetent to transport available materials, less frequent ones of greater magnitude are obviously required. Closer observation of many geomorphic processes is required before the relative importance of different processes and of events of differing magnitude and frequency in the formation of given features of the landscape can be adequately evaluated.
Paired catchment studies have been used as a method to assess the effects of vegetation removal (timber harvesting) on streamflow responses including lowflows and peakflows, but particularly annual water yield. Paired catchment studies in the United States reporting on the effects of timber harvesting on annual water yields were compiled. In general, changes in annual water yield from forest cover reduction (or catchment area harvested) of less than 20% could not be determined by hydrometric or streamflow measurement methods. The catchment studies were discriminated by hydrologic region, defined by temperature and precipitation regimes. This regionalization suggested that as little as 15% of the catchment area (or basal area) could be harvested for a measurable increase in annual water yield at the catchment level in the Rocky Mountain region as compared with 50% in the Central Plains, although system responses are variable. Given changing world-wide objectives for forest land management, hydrologists will be asked to develop monitoring programs to assess the effects of multiple and temporally and spatially distributed land use activities on water resources. Less catchment area will be disturbed, thus monitoring programs must be carefully designed to obtain useful information. The concept of hydrologic recovery, i.e. return to pretreatment condition tends to be based on annual water yield, but also needs the evaluation of streamflow generation and routing mechanisms including lowflows and peakflows when compared with the pretreatment condition.
Clearcutting aspen from the upland portion of an upland peatland watershed in north central Minnesota caused snowmelt peak discharge to increase 11 to 143 percent. Rainfall peak discharge size increased as much as 250 percent during the first two years after clearcutting, then decreased toward precutting levels in subsequent years. Storm flow volumes from rain during the first two years increased as much as 170 percent but declined to preharvest volumes in the third year. Snowmelt volumes did not significantly change. Snowmelt peak discharge occurred about four to five days earlier after clearcutting, but the timing of storm flow from rainfall was not changed.
Snowmelt peaks remained above precut size for nine years after clearcutting on an area undergoing natural regeneration to aspen saplings. Partial cutting ‐ up to approximately one‐half of the watershed ‐ reduced peak snowmelt discharge because melt was desynchronized in cleared and forested parts. Clearing more than 2/3 of the watershed caused snowmelt flood peak size to double during years with snow packs in excess of seven inches of water that remained until a day when maximum air temperatures exceeded 60d̀F.
Long-term changes in annual water yield are summarized and compared for 11 catchment studies in the northeastern USA. Substantial increases in water yield of up to 350 mm year−1 were obtained in the first year by clearing forest vegetation and controlling regrowth with herbicides. Commercial clearcutting with natural regrowth resulted in initial increases in water yield of 110–250 mm year−1. This range in response was due to differences in precipitation and configuration of cuttings. Unless regrowth was controlled with herbicides, yield increases declined quickly after cutting, seldom persisting for more than 10 years. However, yield increases were readily extended over 20 years or more with intermediate cuttings and/or repeated control of regrowth with herbicides. Nearly all increases in water yield occur during the growing season as augmentation of baseflow. Changes in species composition after forest cutting on several study catchments eventually resulted in decreased water yields compared with those from uncut, control catchments. Results are discussed in terms of implications for surface water supplies, global climate change, nutrient cycling, hydrological modeling, and long-term research.
The forest industry plays a major role in the economy of eastern Canada. The recreational fishery also represents an important source of revenue for this area. Therefore, there is concern over the potential economic effects and ecological impacts from logging operations on aquatic habitats. The present study deals with the comparison of streamflow between pre and post timber harvesting at Catamaran Brook (New Brunswick, Canada) to identify any potential changes to the hydrological regime. Studies were carried out on two sub-basins of Catamaran Brook, namely the Middle Reach (mid-basin) and the Upper Tributary 1. The harvested area at the Middle Reach represented 2.3% of this sub-basin while 23.4% of Upper Tributary 1 was harvested. It was noted that during both the calibration and timber harvesting phases, meteorological conditions (e.g. precipitation, runoff) contributed to relatively high natural variability. When studying changes on an annual and seasonal basis for the basin cut at 2.3% (i.e. Middle Reach) and using a control basin for comparison, no changes were detected to the annual water yield, seasonal runoff and streamflow timing between the calibration and timber harvesting phases. On a summer rainfall event basis, no changes were detected at the Middle Reach and the Upper Tributary 1 when studying relations between precipitation and stormflow (obtained through hydrograph separation). Alternatively, changes were detected in relations between peak flows and precipitation (p<0.05) at the Upper Tributary 1 when comparing the calibration and timber harvesting phases. Peak flows showed higher values following timber harvesting. No significant changes were observed between peak flows and precipitation at the Middle Reach.
The effects of clearcut silviculture (road building, clearfelling, cable logging, and site preparation) were evaluated using long-term peakflow records for three small watersheds (60–101 ha) and six large basins (62–640 km2) in the western Cascades of Oregon, USA. After a calibration period, two of the small watersheds were treated while the third remained untreated (control). Analysis indicated that peakflow increases following treatments were dependent upon peakflow magnitude. Peakflow increases averaged approximately 13–16% after treatment for 1-yr recurrence interval events, and 6–9% for 5-yr recurrence interval events. For the six large basins, multiple linear regression analyses of peakflows relative to: (1) peakflow magnitude; and (2) difference in percent area harvested provided mixed results. While significant (p<0.05) relationships were found in half of the analyses, the explained variance (Δr2) due to harvesting was generally small (1–7%).
This summary and review of 94 catchment experiments shows that accumulated information on the effect of vegetation changes on water yield can be used for practical purposes. The direction of change in water yield following forest operations can be predicted with fair accuracy since no experiments, with the exception of perhaps one, have resulted in reductions in water yield with reductions in cover, or increases in yield, with increases in cover. The approximate magnitude of changes can also be estimated. Pine and eucalypt forest types cause on average 40-mm change in water yield per 10% change in cover and deciduous hardwood and scrub ∼25 and 10 mm, respectively. Maximum changes of 660 mm were experienced at Coweeta, North Carolina. An assimilation of the collective experimental results shows that more careful design and expansion of experiments to certain rainfall regions would augment statistical inference.
Increase in bankfull peak flows and a reduction of lag and base times of the storm hydrographs were the only change in stormflow characteristics observed after harvesting balsam fir stands over 85% of the area of basin 7A (122 ha) at Montmorency Forest (Quebec, Canada). The maximum peak flow increase by 63% and occurred when harvesting had reached 61% of the basin area. For the five-year period after harvesting 85% of the basin area, the maximum increase of bankfull flow was 57% while the average change derived from the regression between the treatment and control basin during the pre-harvest period was 54%. These peak flow changes were compared with results from harvesting effects on bankfull peak flow from 50 paired watershed studies. The maximum increase in peak flow of 63% (basin 7A) was at the upper end of published results for harvesting 45–70% of a basin area while a 54% peak flow increase corresponded to the average value (49%) of published results for the 70–100% harvesting intensity. The relatively high peak flow response of basin 7A was mainly attributed to the connections of skid trails and road ditches with two branches of the stream. Considered globally, the results from watershed studies indicate that logging should not cover more than 50% of a basin area to minimise the occurrence of peak flow increases above 50%, which are deemed to affect stream morphology significantly.
The exploitation of land and water resources to sustain an ever-increasing population inevitably involves the utilisation for both urban and agricultural development of rural areas and the natural landscape. This process can result in profound changes to the flow regime of river basins that are so affected, the scope and magnitude of which have been investigated by means of experimental catchment studies. The extensive data base that has resulted from such activities has provided a basis for developing a series of generalised relationships which can be used by water resources planners to anticipate the changes in water yield that can result from alterations to the predominant vegetative cover of a catchment. The application of fuzzy linear regression analysis to data from 145 experiments has shown that, for a 10% reduction in cover, the yield from conifer-type forest increased by some 20–25 mm, whereas that for eucalyptus-type forest increased by only 6 mm. Both values were somewhat lower than those previously published, as was the 5 mm decrease in yield associated with a 10% afforestation of scrub. A 10% reduction in the cover of deciduous hardwood gave a 17–19 mm increase in yield, broadly in line with earlier estimates.
This book reviews many of the problems which currently confront the environmental planner - problems which promise to become even more signifcant in the near future. Water resources are examined essentially from a physical standpoint, although throughout the text the emphasis is on the application of basic hydrologic principles in problem solving. The stated aim of the authors is to make all those concerned with planning more aware of the opportunities and constraints of natural processes in maintaining or reclaiming environmental quality. They are successful in outlining the significant role of water in many environmental issues. The book provides a comprehensive review of the current literature associated with water resources, but perhaps more importantly can also be used as an introductory working document in dealing with particular environmental problems. Several chapters for instance include working examples to illustrate specific problem-solving techniques. The book is divided into four sections, the first of which describes six case studies and exemplifies many of the problems facing the environmental planner today. The remaining three sections discuss basic hydrologic principles, fluvial geomorphology and water quality, stressing the value of such studies for improved environmental management. The text is supplemented by bibliographies, photographs, tables, and diagrams.
The watershed management program at the Montmorency experimental forest. Usefulness of an experimental forest research and teaching, Symposium
- A P Plamondon
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Plamondon, A.P., Naud, R.C., 1975. The watershed management
program at the Montmorency experimental forest. Usefulness of
an experimental forest research and teaching, Symposium, Forêt
Montmorency. Faculté de foresterie, Université Laval, Québec,
pp. 129-152.
Validation of water yield thresholds on the Kootenai National Forest. Depart-ment of Earth Resources The Canadian system of soil classification
- L H Macdonald
- E E Wohl
- S W Madsen
MacDonald, L.H., Wohl, E.E., Madsen, S.W., 1997. Validation of water yield thresholds on the Kootenai National Forest. Depart-ment of Earth Resources, Colorado State University, Fort Collins, CO., p. 197. NRC, 1998. The Canadian system of soil classification. National Research Council Canada, Ottawa, p. 188.
Effects of Pinyon-Juniper removal on natural resources products and uses in Arizona
- W P Clary
- B Baker
- P F O'connell
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Clary, W.P., Baker, B., O'Connell, P.F., Johnsen, T.N., Campbell,
R.E., 1974. Effects of Pinyon-Juniper removal on natural
resources products and uses in Arizona. USDA Forest Service
Research Paper RM-128, p. 28
Influence des coupes forestières sur le régime d’écoulement de l’eau et sa qualité
- A P Plamondon
Plamondon, A.P., 1993. Influence des coupes forestières sur le ré d'e ´coulement de l'eau et sa qualité. Revue de litté-ture. Ministère des Forê du Qué. Rapport C-47, p.
Paysages ré du Qué mé. Publications du Qué Hydrological study of Ruisseau des Eaux-Volé experimental basin The effects of afforestation and deforestation on water yields
- A Robitaille
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Robitaille, A., Saucier, J.P., 1998. Paysages ré du Qué mé. Publications du Qué, St-Foy, p. 213. Rochette, F.J., 1971. Hydrological study of Ruisseau des Eaux-Volé experimental basin. M.Sc. thesis, University of Western Ontario, p. 88. Rousselle, J., Watt, W.E., Lathem, K.W., Neill, C.R., Richards, T.L., 1990. Hydrologie des crues au Canada – Guide de planification et de conception. Conseil National de Recherches Canada, Ottawa, p. 227. Sahin, V., Hall, M.J., 1996. The effects of afforestation and deforestation on water yields. Journal of Hydrology 178, 293– 309.
Changes in spawning gravel characteristics after forest harvesting in Queen Charlotte Island and Carnation Creek watersheds and the apparent impacts on incubating eggs Applying 20 years of coast research to man-agement solutions. British–Columbia. Ministry of forest research program
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Design and analyses of the catchment experiment
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Hewlett, J.D., Pienaar, L., 1973. Design and analyses of the
catchment experiment. In: White, E.D. (Ed.), Proceedings
Symposium on the use of small watersheds in determining the
effects of forest land use on water quality, pp. 88-106.
Streamflow and water quality: what does the science show about clearcutting in Western Oregon, National Council for Air and Stream Improvement
- G Ice
Ice, G., 1999. Streamflow and water quality: what does the science
show about clearcutting in Western Oregon, National Council for
Air and Stream Improvement, Oregon State University, Corvallis,
Oregon, p. 20.
The effects of logging and mass wasting on salmonid spawning habitat in streams on the Queen Charlotte Islands
- D B Tripp
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Tripp, D.B., Poulin, V.A., 1986. The effects of logging and mass
wasting on salmonid spawning habitat in streams on the Queen
Charlotte Islands, Land Management Report 50. British-Columbia Ministry of Forests and Lands, Land Management Report 50,
p. 19.
Demographic and habitat requirements for conservation of bull trout
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Rieman, B.E., McIntyre, J.D., 1993. Demographic and habitat
requirements for conservation of bull trout. USDA Forest
Service, Intermountain Research Station, Gen. Tech. Rep. INT-302, p. 38.
Changes in streamflow following timber harvest in southwestern Oregon
- R D Harr
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Harr, R.D., Frederiksen, R.L., Rothacher, J., 1979. Changes in
streamflow following timber harvest in southwestern Oregon.
Water Resources Research 15, 90-96.
World reference base for soil resources A re-evaluation of peak flows: Do forest roads and harvesting cause floods? 1999 NCASI West Coast Regional Meeting, National Council of the Paper Industry for Air and Stream Improvement Effet De la coupe sur le bilan hydrologique
- J M Faustini
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Faustini, J.M., 2000. Stream channel response to peak flows in a fifth-order mountain watershed, PhD Thesis, Oregon State University, p. 339 FAO, 1998. World reference base for soil resources. Food and Agriculture Organization of the United Nations, Rome, p. 84. Grant, G.E., Megahan, W.F., Thomas, R.B., 1999. A re-evaluation of peak flows: Do forest roads and harvesting cause floods? 1999 NCASI West Coast Regional Meeting, National Council of the Paper Industry for Air and Stream Improvement, Portland, OR. Guillemette, F., Plamondon, A.P., Lé, D., 1998. Effet De la coupe sur le bilan hydrologique. Bassin expé du ruisseau des Eaux-Volé. Rapport du Ministère des Ressources Natur-elles. Université Laval, p. 65. Guillemette, F., Plamondon, A.P., Pré, M., Lé, D., 2005. Rainfall generated stormflow response to clearcutting a boreal forest: peak flow comparison with 50 world-wide basin studies. Journal of Hydrology 302, 137–153.
La ré forestière et les dé de pointe: E ´ tat des connaissances sur la pré des augmenta-tions des pointes, le concept de l'aire e ´quivalente de coupe acceptable et les taux ré des effets de la coupe sur les dé de pointe
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Plamondon, A.P., 2004. La ré forestière et les dé de pointe: E ´ tat des connaissances sur la pré des augmenta-tions des pointes, le concept de l'aire e ´quivalente de coupe acceptable et les taux ré des effets de la coupe sur les dé de pointe. Direction de l'Environnement forestier, Min-istère des Ressources naturelles, Gouvernement du Qué, p.
Meilleur ajustement statistique aux débits journaliers de crue et d'étiage des rivières du Québec. Ministère des richesses naturelles, Direction générale des eaux
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Hoang, V.D., 1978. Meilleur ajustement statistique aux débits
journaliers de crue et d'étiage des rivières du Québec. Ministère
des richesses naturelles, Direction générale des eaux, Service de
l'hydrométrie, Québec, p. 28.
Plan général d'aménagement de la forêt Montmorency
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Bélanger, L., Bertrand, L., Bouliane, P., Lussier, L.J., 1991. Plan
général d'aménagement de la forêt Montmorency. Université
Laval, p. 216.
Prédiction de la teneur en eau du sol minéral dans la sapinière laurentienne de la forêt Montmorency. Mémoire de maîtrise
- R Barry
Barry, R., 1984. Prédiction de la teneur en eau du sol minéral dans
la sapinière laurentienne de la forêt Montmorency. Mémoire de
maîtrise, Université Laval, p. 100.
Peak and storm flow response to forest road construction, Mémoire de maîtrise
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Beaudin, 2002. Peak and storm flow response to forest road
construction, Mémoire de maîtrise, Université Laval, Quebec,
p. 60.
A re-evaluation of peak flows: Do forest roads and harvesting cause floods? 1999 NCASI West Coast Regional Meeting, National Council of the Paper Industry for Air and Stream Improvement
- G E Grant
- W F Megahan
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Grant, G.E., Megahan, W.F., Thomas, R.B., 1999. A re-evaluation of
peak flows: Do forest roads and harvesting cause floods? 1999
NCASI West Coast Regional Meeting, National Council of the
Paper Industry for Air and Stream Improvement, Portland, OR.
Watershed calibration methods Forest Hydrology
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Reinhart, K.G., 1967. Watershed calibration methods. In: Sopper, W.E., Lull, H.W. (Eds.), Forest Hydrology. Pergamon Press, Oxford, pp. 715–721.
Hydrological study of Ruisseau des Eaux-Volées experimental basin
- F J Rochette
Rochette, F.J., 1971. Hydrological study of Ruisseau des Eaux-Volées experimental basin. M.Sc. thesis, University of Western
Ontario, p. 88.
Hydrologie des crues au Canada -Guide de planification et de conception. Conseil National de Recherches Canada
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Rousselle, J., Watt, W.E., Lathem, K.W., Neill, C.R., Richards, T.L.,
1990. Hydrologie des crues au Canada -Guide de planification
et de conception. Conseil National de Recherches Canada,
Ottawa, p. 227.
Changes in streamflow following timber harvest in southwestern Oregon
- Harr
Meilleur ajustement statistique aux débits journaliers de crue et d’étiage des rivières du Québec. Ministère des richesses naturelles, Direction générale des eaux, Service de l’hydrométrie
- V D Hoang
Changes in spawning gravel characteristics after forest harvesting in Queen Charlotte Island and Carnation Creek watersheds and the apparent impacts on incubating eggs
- J C Scrivener
- D B Tripp
Scrivener, J.C., Tripp, D.B., 1998. Changes in spawning
gravel characteristics after forest harvesting in Queen
Charlotte Island and Carnation Creek watersheds and the
apparent impacts on incubating eggs. In: Hogan, D.L.,
Tschaplinski, P.J., Chatwin, S. (Eds.), Proceedings of the
Carnation Creek and Queen Charlotte Island fish/forestry
Workshop: Applying 20 years of coast research to management solutions. British-Columbia. Ministry of forest
research program, Land Management Handbook 41, pp.
135-140.
Effet De la coupe sur le bilan hydrologique
- F Guillemette
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Guillemette, F., Plamondon, A.P., Lévesque, D., 1998. Effet De la
coupe sur le bilan hydrologique. Bassin expérimental du ruisseau
des Eaux-Volées. Rapport du Ministère des Ressources Naturelles. Université Laval, p. 65.
Validation of water yield thresholds on the Kootenai National Forest. Department of Earth Resources
- L H Macdonald
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MacDonald, L.H., Wohl, E.E., Madsen, S.W., 1997. Validation of
water yield thresholds on the Kootenai National Forest. Department of Earth Resources, Colorado State University, Fort Collins,
CO., p. 197.
Morphological relationships of rural watercourses in southwestern Ontario for use in natural channel designs
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Annable, W.K., 1995. Morphological relationships of rural watercourses in southwestern Ontario for use in natural channel
designs. University of Guelph.
Influence des coupes forestières sur le régime d'écoulement de l'eau et sa qualité. Revue de littérature
- A P Plamondon
Plamondon, A.P., 1993. Influence des coupes forestières sur le
régime d'écoulement de l'eau et sa qualité. Revue de littérature. Ministère des Forêts du Québec. Rapport C-47, p.
179.