Stream Temperature Drivers and Modelling in Headwater Catchments on the Eastern Slopes of the Canadian Rocky Mountains PDF Download

Author: Ryan J. MacDonald
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 220

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Author: John C. Risley
Publisher:
ISBN:
Category : Neural networks (Computer science)
Languages : en
Pages : 74

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Author: Travis R. Roth
Publisher:
ISBN:
Category : Energy budget (Geophysics)
Languages : en
Pages : 85

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Headwater streams are an integral part of the ecological health of the greater stream network as they provide valuable biological habitat, provide upwards to 95% of total in channel flow, while providing downstream reaches with important constituents such as sediment and woody debris. Small headwater streams are particularly susceptible to anthropogenic and natural disturbances that affect their runoff production, chemical make-up, and thermal regime. Based on their position in the drainage basin and contribution to stream flow, heat energy transfer within a small mountain stream helps establish the thermal regime of the downstream lower order streams. However, headwater catchment thermal function remains poorly understood. Stream temperature is a manifestation of the environment through which it flows and the mechanisms by which it reaches the stream. Subsurface process controls, such as local soil properties, bedrock topography, and lateral flow discharge play an important role in headwater stream generation. Study outcomes are a result of vigorous field experimental work at the Watershed 07 (WS07) stream at the H.J. Andrews Experimental Forest (HJA) located in the Western Cascades, Oregon. Bedrock Topography was delineated through the use of a dynamic cone penetrometer, local lateral inflow sources were identified and quantified through the application of a salt tracer, and the energy budget was characterized through the use of Distributed Temperature Sensing (DTS) technology. High gradient, low volume streams such as WS07 provide unique challenges for DTS deployment which require extensive post-calibration data analysis. An automated cable submersion identification process was developed and was carried out on the collected temperature data with 32.8 % (379 of 1155) of measured temperature points identified as "in-water". Uncertainty propagation analysis associated with DTS measurement was calculated to be 0.21 °C. Salt tracer application found that 2 localized lateral inflow discharge to the stream accounted for 15% and 16% of total discharge in the upper section of the stream. Downstream lateral inflows exhibited incremental additions to stream discharge on the order of 5%. Stream discharge increased by 1.13 l/s from the upper section to the start of the lower section, an increase of 45%. Substantial lateral inflows provided reduction of stream temperatures in the lower section. Using DTS technology we measured stream temperature as a validation method for a physically based energy balance stream temperature model to characterize energy controls on stream temperature. Analysis of model performance was determined through root mean square error with reported values of 0.38 °C and 0.32 °C for the upper and lower section, respectively. Total energy inputs into the upper and lower sections of the stream were 302 W/m2 and 210 W/m2. Primary energy balance components were found to be solar radiation, atmospheric longwave radiation, and bed conduction. Solar radiation accounted for 63% of total energy flux into the stream in the upper section and 28% in the lower section. This is primarily a result of the distinct vegetation differences between the two reaches. Atmospheric longwave radiation contributed 27% and 26% of total energy flux in the upper and lower sections, respectively. While bed conduction made up 11% and 24% of the total flux in the upper and lower sections.

Author: E. F. Durrant
Publisher:
ISBN:
Category : Eastern Slopes Region (Alta.)
Languages : en
Pages : 12

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Author: Cindie Hébert
Publisher:
ISBN:
Category :
Languages : en
Pages : 400

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ABSTRACT: Water temperature is a key physical habitat determinant in lotic ecosystems as it influences many physical, chemical and biological properties of rivers. Hence, a good understanding of the thermal regime of rivers is essential for effective management of water and fisheries resources. This study deals with the modeling of hourly stream watertemperature using a deterministic model, an equilibrium temperature model and an artificial neural network model. The water temperature models were applied on two thermally different streams, namely, the Little Southwest Miramichi River (LSWM) and Catamaran Brook (Cat Bk) in New Brunswick, Canada. The deterministic model calculated the different heat fluxes at the water surface and from the streambed, using different hydrometeorological conditions. Results showed that microclimate data are essential in making accurate estimates of the surface heat fluxes. Results also showed that for larger river systems, the surface heat fluxes were generally the dominant component of the heat budget with a correspondingly smaller contribution from the streambed (90%). As watercourses became smaller and as groundwater contribution became more significant, the streambed contribution became important (20%). The equilibrium temperature model is a simplified version of the deterministic model where the total heat flux at the surface is assumed to be proportional to the difference between the water temperature and the equilibrium temperature. The poor model performance compared to the other models developed in this study suggested that the air and equilibrium temperature did not reflect entirely the total heat flux at an hourly scale.

Author: Lorraine E Flint
Publisher: CreateSpace
ISBN: 9781500485924
Category : Technology & Engineering
Languages : en
Pages : 38

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Stream temperature estimates under future climatic - ing for evaluation of effects of dam removal in the Klamath River Basin. To allow for the persistence of the Klamath River 2012 will review potential changes in water quality and stream temperature to assess alternative scenarios, including damusing a regression model approach with simulated net solar temperature, and mean daily air temperature. Models were calibrated for 6 streams in the Lower, and 18 streams in the Upper, Klamath Basin by using measured stream temperatures for 1999–2008. The standard error of the y-estimate for the estimation of stream temperature for the 24 streams ranged from 0.36 to 1.64 degrees Celsius (°C), with an average error of 1.12°C for all streams. The regression models were then used with projected air temperatures to estimate future stream temperatures for 2010–99. Although the mean change from the baseline historical period of 1950–99 to the projected future period of 2070–99 is only 1.2°C, it ranges from 3.4°C for the Shasta River to no change for Fall Creek and Trout Creek. Variability is also evident in the future with a mean change in temperature for all streams from the baseline period to the projected period of 2070–99 of only 1°C, while the range in stream temperature change is from 0 to 2.1°C. The baseline period, 1950–99, to which the air temperature projections were corrected, established the starting point for the projected changes in air temperature. The average measured daily air temperature for the calibration period 1999–2008, however, was found to be as much as 2.3°C higher than baseline for some rivers, indicating that warming conditions have already occurred in many areas of the Klamath River Basin, and that the stream temperature projections for the 21st century could be underestimating the actual change.

Author:
Publisher:
ISBN:
Category : Forest management
Languages : en
Pages : 380

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Author: Douglas McKinnon Allen
Publisher:
ISBN:
Category :
Languages : en
Pages : 410

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Author: Joseph Ariwi
Publisher:
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Category :
Languages : en
Pages :

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"Water temperature is a key component in freshwater aquatic environments, acting as a driver of habitat processes and a trigger of life cycle events for riverine invertebrate and vertebrate species. Habitat suitability for fish species can be defined by maximum and minimum temperature tolerances and both habitat-forming processes and migratory behaviors are a function of localized thermal regimes. The salience of thermal regimes on river ecology is of particular importance given the increased alteration of riverscapes through the construction of impoundments, as well as the abstraction and deposition of large volumes of water in industrial and agricultural practices that alter thermal regimes. Thermal regimes have also been shown to be impacted by global climate change. River temperature data is available at a high resolution through the use of remote sensing along individual river reaches or from onsite measurements at river gauging stations. There is, however, a lack of high resolution river temperature data at the global scale of a consistent quality that captures the full spatiotemporal temperature variation in every river reach. Using two main estimation approaches - a local technique and a physically based river network mixing technique - four temperature estimation models are developed. The four models were developed using global data for global application, but were only applied within the contiguous United States of America. The results present the spatiotemporal patterns of simulated long-term mean monthly river temperatures. The estimates are evaluated using observed data across the contiguous United States of America and the effectiveness of the estimation methods are compared and contrasted. Within the scope of this study, a logistic function with optimized model parameters was found to be the best performing stream temperature estimation model, producing strong validation statistics across different terrestrial biomes. However, the performance of this technique was found to be poor in rivers impacted by anthropogenic flow regulation, glacier or snow melt, and other perturbations. The data produced will be of value in ecological assessments and provides a baseline for global stream temperature data at a high spatial resolution." --

Author: Gwendolynn Wolfheim Bury
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 208

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Climate change is predicted to affect ecosystems, including systems already stressed by human impacts. One ecosystem that is already highly impacted by human land use is the cold headwater stream system of the Pacific Northwest. One method of assessing the function of an ecosystem is by using an indicator species. Rhyacotriton variegatus is one such indicator species, sensitive to disturbance, and especially to temperature elevation. This study combines field measurements from the warmest edge of the range of R. variegatus, laboratory determination of thermal tolerance, and modeling. These diverse experimental sources combine to clarify the potential risks of climate change on R. variegatus, and the headwater streams they occupy. Abiotic factors are important determinates of the range of species. Predicted range shifts under climate change are based on the assumption that temperature increases will make habitat at the edge of the known range unsuitable in the future. In order to accurately predict such changes, a quantification of the current thermal boundary is needed. In Chapter Two, I placed temperature loggers and measured other environmental variables in 28 streams: 8 in the cool core of the range of R. variegatus, 10 as far east and south as R. variegatus has ever been found, and 10 outside the known range of R. variegatus. The variables which best defined the range edge were degree days (number of days over specific temperatures), and the slope of the stream bed. Specific physiological tolerance information is also essential for accurate modeling of species habitats. Physiological limits should be determined experimentally using procedures that mimic natural conditions as closely as possible, so that the results will be applicable to natural systems. Forecasting the effects of human activities on populations also requires an understanding of how specific abiotic changes will impact different life stages. I used a realistic cycling temperature treatment in Capters Three and Four, based on the data collected in Chapter One. I tested the survival of larval R. variegatus at a chronic exposure (21 days), and the level of stress as measured by corticosterone in adult R. variegatus. Larval R. variegatus survived up to a daily maximum of 23° C, beyond this the larvae died (LT 50 value of 24° C). I found that daily maximum temperatures over 18° C caused a doubling of corticosterone. There are many ways of modeling future climate change and the effect of this change on species' distribution. I chose to use large array of potential climate futures, modeling methods, and time periods to forecast the change in R. variegatus' range. This allowed me to compare the variation between the predictions for climate change, and find averages across the models. I used two correlative models, and one mechanistic model. The mechanistic model incorporated the relationship between air and water temperature from Chapter Two, and the physiological limits from Chapters Three and Four. All models predicted decreases in areas of the map classified as excellent habitat for R. variegatus. As expected, the reduction in range was most severe at longer time periods into the future, with higher CO2 amounts in the atmosphere, and in models that incorporated more abiotic variables. R. variegatus are sensitive indicators for headwater stream ecosystem function, and will have a reduced range under climate change.