This research is intended to determine the role of riparian vegetation in stream morphology. This experiment examined the effects of riparian vegetation on boundary shear stress (BSS) by completing the following objectives: (1) evaluating the effects of streambank vegetation on near-bank velocity and turbulence; (2) determining a method for measuring BSS; and, (3) examining the effects of streambank vegetation on BSS using an existing model. A second order prototype stream, with individual reaches dominated by the three vegetation types (trees, shrubs, and grass) was modeled using a fixed-bed Froude-scale modeling technique. One model streambank of the prototype stream was constructed for each vegetation type in addition to one bank with only grain roughness. Velocity profiles were measured using an acoustic Doppler velocimeter (ADV) and a miniature propeller (MP). A flush-mounted Dantec MiniCTA system was used to measure shear stress at the streambank wall. The addition of vegetation on a sloping streambank increased the streamwise free stream velocity and decreased the near-bank streamwise velocity. The turbulence caused by the upright shrub treatment increased turbulent kinetic energy and Reynolds stresses near the streambank toe, an area susceptible to fluvial erosion. The presence of dense, semi-rigid vegetation may encourage the formation of a wider channel with a vertical streambank. The small range of CTA shear stress measurements (0.02—2.14 Pa) suggested that one estimate can describe a streambank. The law of the wall technique is not appropriate because the velocity profiles did not follow the necessary logarithmic shape. Vegetative roughness present in channels created secondary flow; turbulence characteristics more appropriately estimated BSS. The BSS model predicted velocity fields in similar distribution to that measured by the ADV and MP. BSS calculated using the ray-isovel method for both velocity measurement devices were different than the measured BSS values, likely due to distortions in the measured velocity field. In general, the predicted BSS distribution increased with water depth and decreased with increasing vegetation density. The predicted BSS at the shrub toe indicated a spike in shear stress consistent with TKE estimates. / Ph. D.

Yes / Based on the Lagrangian approach, this study proposes a random displacement model (RDM) to predict the concentration of suspended sediment in vegetated steady open channel flow. Validation of the method was conducted by comparing the simulated results by using the RDM with available experimental measurements for uniform open-channel flows. The method is further validated with the classical Rouse formula. To simulate the important vertical dispersion caused by vegetation in the sediment-laden open channel flow, a new integrated sediment diffusion coefficient is introduced in this study, which is equal to a coefficient multiplying the turbulent diffusion coefficient. As such, the RDM approach for sandy flow with vegetation was established for predicting the suspended sediment concentration in low-sediment-concentration flow with both the emergent and submerged vegetation. The study shows that the value of for submerged vegetation flow is larger than that for emergent vegetation flow. The simulated result using the RDM is in good agreement with the available experimental data, indicating that the proposed sediment diffusion coefficient model can be accurately used to investigate the sediment concentration in vegetated steady open channel flow. / National Natural Science Foundation (No. 51439007, 11672213, and 11872285); Open Funding of State Key Laboratory of Water Resources and Hydropower Engineering Science (WRHES), Wuhan University (Project No: 2018HLG01)

This study into the architectural profession reviews developed decision support frameworks (graphics to inform and improve decision making through access to more information) as knowledge sharing devices. These developed frameworks first, influence decision makers: the students and their decisions in their personal architectural design process and second, develop a framework on vegetated assemblies (building assemblies that incorporate plants such as green roofs and walls) as vegetated assemblies relate to color theory and its implications in design methodology. This decision support framework assists students in their design process in studio and studio-like educational environments. The purpose of this decision support framework is to influence the students in using vegetated assemblies in their future design inquiry. After implementation, the purpose was to determine the worth of the framework as a mechanism for knowledge sharing. Both purposes were reviewed in developing the framework using immersive case studies, classes both in traditional studios and studio-like courses, website development and member feedback. The evidence of the resulting improvement of decision making or design work was found through the use of surveys, student reflective writing, and personal interpretation of student works and my own immersive design studies, classes, and development of the framework and its website. The surveys and reflective writing were collected from multiple years of involvement in traditional studio and studio-like classes to refine the framework and its use. The results of the study suggest that students do have a larger body of knowledge to make decisions about utilizing vegetated assemblies than before the use of the framework and go on the continue using vegetated assemblies in design work. The framework presents the various factors that impact decisions into vegetated assemblies and develop future designs. By influencing and improving knowledge of such factors on the design of vegetated assemblies early in a student's education, improves decision making in future designs and later professional work. Future work would be targeted at refining the framework and potential courses to include other topics of interest in relation to vegetated assemblies. Finally, the framework could be adapted into a more codified, interactive tool in the future. / Ph. D. / This study looks at how graphics and representation can improve the making of decisions on the basis of access to more information across different learning environments. This process of gathering and then sharing information with others can develop into knowledge sharing devices. These devices also known as decision support structures are a scaffold or framework for influencing decision makers: the students. The influence is on their developed design process, how students go about designing, and on their knowledge of vegetated assemblies, which are parts of buildings that incorporate plants such as green roofs and walls, and color theory, which is a method for using color in design. This decision support structures assists students in their design process in studio and studio-like educational environments. The purpose of this dissertation is to review how decision support structures can be used various learning environments to assist students in exploring lines of inquiry. These lines of inquiry are a deliberate process of exploring an idea or family of ideas. This use of the decision support structure was reviewed using immersive case studies, classes both in traditional studios and studio-like courses, and the development of a website. The results of the study suggest that students do have a larger body of knowledge to make decisions when using the developed decision support structure. This work presents the various factors that impact decisions into developing future designs based on vegetated assemblies and color theory as topics. This work also improves decision making in future designs and later professional work. Future work would be targeted at refining the developed decision support structure and potential courses to include other topics of interest in relation to vegetated assemblies. Finally, the framework could be adapted and expanded in the future.

Previous field demonstration projects in metro-Atlanta have shown that seep berms, which are elongated sedimentation basins at the outlet of a disturbed land area, can provide high suspended sediment trap efficiencies with respect to coarse sediments on construction sites having drainage areas greater than five acres. Previous literature has shown that vegetative filter strips are efficient traps for fine suspended sediment in stormwater runoff. A combination of a seep berm and vegetative filter in series was studied in this thesis as an erosion control measure with quantification of its flow resistance and sediment removal efficiency. First, a field demonstration project was implemented to evaluate seep berms as a viable erosion control measure through a side-by-side comparison with the more commonly-used silt fences on construction sites with drainage areas less than five acres in metro Atlanta. High suspended sediment trap efficiencies were recorded for the seep berm on two separate sites, and the seep berm was shown to be superior to silt fences with respect to sediment control in the site runoff. Then a vegetative filter was studied in the laboratory in a specially-built flume for that purpose. The relationship between vegetative drag coefficient and various parameters reflecting flow conditions and vegetation density in steady, uniform open channel flow was studied in the flume. Both rigid, emergent vegetation and submerged, flexible vegetation were studied at two different plant densities. The application of porous media flow concepts to open channel flow through vegetation resulted in a collapse of data for vegetative drag coefficient for the various vegetation types and densities into a single relationship when plotted against vegetative stem Reynolds number. Point velocity and turbulence intensity profiles at different locations in the vegetative filter were recorded with an acoustic Doppler velocimeter to observe the turbulence structure of the flow and its effects on vegetative drag and settling of sediment. A sediment slurry consisting of a suspension of fine sand was fed into the flume, and an automated sampler was used to measure suspended sediment concentrations along the vegetative filter length for a series of discharges from which sediment flux and trap efficiency could be determined. Experimental data for trap efficiency were plotted against a dimensionless settling efficiency for each type of vegetation and density. These relationships, along with the one developed for the coefficient of drag, were applied in a numerical design technique that allows designers to determine the flow depth, velocity and trap efficiency of a vegetative filter of known dimensions for a given flow rate, sediment grain size distribution, slope, and vegetation density. In a typical design example, the combined trap efficiency proved that a seep berm followed by a vegetative filter can be a very effective erosion control measure.

Highway runoff transport high concentrations of heavy metals. As climate change affect the environment with for example increased storm events, the treatment of road runoff becomes more important. This study aims to evaluate the treatment of highway runoff with constructed wetlands, stormwater ponds, vegetated filterstrips, vegetated swales and filter materials for highways in proximity to nature reserves. The treatment efficiency of constructed wetlands, stormwater ponds, vegetated filterstrips and vegetated swales was examined through a literature study and modelling of the different treatment methods using the StormTac modelling tool. Modelling was done both based on the design of a facility from the literature study and also adapted to a study area along the Södertörn Crosslink. The treatment efficiency of a sand filter as well as four reactive filter materials was determined from field studies on a pilot plant in Gröndal. The results from the study show that the guidelines for stormwater quality from Järfälla municipality can be reached with the treatment of stormwater using filter material. The treatment of heavy metals with constructed wetlands and stormwater ponds is below the guidelines for stormwater quality from Järfälla municipality for some of the studied heavy metals. However, the results from the modelling show a higher treatment efficiency than from the literature study for the majority of the studied metals. Moreover, construed wetlands and stormwater ponds also provide areas for recreation and promotion of biodiversity, which in a nature reserve area should be considered beneficial. A common issue for stormwater treatment with constructed wetlands, stormwater ponds and filter materials are that the required area for filter materials with pre-sedimentation basin, as well as the requested area for constructed wetlands and stormwater ponds, are bigger than the designated area for treatment in the case study. / Dagvatten från motorvägar för med sig höga halter tungmetaller. Effekterna av klimatförändringar påverkar miljön med till exempel fler och häftigare regn, vilket leder till att rening av vägdagvatten blir allt viktigare. Denna studie syftar till att utvärdera rening av dagvatten från motorvägar med konstruerade våtmarker, dagvattendammar, översilningsytor, svackdiken och filtermaterial för motorvägar i nära anslutning till naturreservat. Reningseffektiviteten för konstruerade våtmarker, dagvattendammar, översilningsytor och svackdiken undersöktes genom en litteraturstudie och modellering av de olika reningsmetoderna i modelleringsverktyget StormTac. Modellering gjordes både utifrån utformning av en anläggning från litteraturstudien, men även för en anläggning anpassad till ett studieområde längs Tvärförbindelse Södertörn. Reningseffektiviteten för ett sandfilter samt fyra reaktiva filtermaterial bestämdes från fältstudier på en pilotanläggning i Gröndal. Resultaten från studien visar att riktlinjerna för dagvattenkvalitet från Järfälla kommun kan nås med rening av dagvatten med filtermaterial. Reningen av tungmetaller med anlagda våtmarker och dagvattendammar ligger under riktlinjerna för dagvattenkvalitet från Järfälla kommun för några av de studerade tungmetallerna, dock visar resultaten från modelleringen en högre reningseffektivitet än från litteraturstudien för majoriteten av de studerade tungmetallerna. Konstruerade våtmarker och dagvattendammar skapar även områden för rekreation och främjande av biologisk mångfald, vilket i ett naturreservatsområde bör anses vara fördelaktigt. Ett gemensamt problem för dagvattenrening med anlagda våtmarker, dagvattendammar och filtermaterial är att det området som krävs för filtermaterial med försedimenteringsbassäng, samt det önskvärda området för anlagda våtmarker och dagvattendammar är större än det avsedda området för rening i fallstudien.

In 2011, the Deep River Portage-Burns Waterway Watershed was identified as a priority in the Northwest Indiana watershed management framework by the Northwester Indiana Regional Planning Committee. 319 grant cost-share programs were initiated in effort of maintaining and restoring the health of Deep River Portage-Burns Waterway Watershed. A watershed management plans have been developed for this watershed which proposed the implementation of vegetated filter strips (VFS) as an option. In this thesis work, the effectiveness of VFS as a best management practice (BMP) for the Deep River system was evaluated using a hydrological model scheme. <div><br></div><div>In this research, a Nonpoint Source Pollution and Erosion Comparison Tool (NSPECT) model and a Soil Water Assessment Tool (SWAT) model were constructed with required watershed characteristic data and climate data. The initial hydrologic and nutrient parameters of the SWAT model were further calibrated using SWAT Calibration and Uncertainty Programs (SWAT_CUP) with historical flow and nutrient data in a two-stage calibration process. The calibrated parameters were validated to accurately simulate the field condition and preserved in SWAT model for effectiveness analysis of BMP implementations. </div><div><br></div><div>To evaluate the effectiveness of VFS as a BMP, four different scenarios of VFS implementations along the Turkey Creek was simulated with the calibrated SWAT model. With the implementation of VFS in the tributary subbasin of Turkey Creek, the annual total phosphorus (TP) of the VFS implemented subbasin was reduced by 1.60% to 78.95% and the annual TP of downstream subbasins were reduced by 0.09% to 55.42%. Daily percentage of TP reductions ranged from 0% to 90.3% on the VFS implemented subbasin. Annual TP reductions of the four scenarios ranged from 28.11 kg to 465.01 kg.<br></div>

La préservation de la qualité de l’eau est un enjeu majeur du 21ème siècle notamment avec l’augmentation de la population humaine. Or les rejets de stations d’épuration représentent un risque de pollution du milieu récepteur, notamment en azote et phosphore, aux effets néfastes pour la santé et l’environnement. C’est pour limiter cette pollution que les zones tampon végétalisées (ZTV), systèmes d’infiltration ou d’écoulement des effluents, plantés d’espèces végétales, ont été développées. Cette étude a pour objectif principal de mieux comprendre les transferts de nutriments dans ce type de système. L’impact des différents compartiments –Sol, végétation, microflore- a été étudié dans deux ZTVs de type « noues » situées en aval de stations d’épuration végétalisées en activité et dans une zone expérimentale aux modalités contrôlées. Cette étude a démontré l’importance de l’hydraulique du site, de la texture du sol et de la surface de la zone dans l’efficacité de rétention des flux d’eau et nutriments. L’impact du compartiment microbien dépend en grande partie du temps de rétention hydraulique lié à la surface de la ZTV, et du taux d’oxygénation de l’effluent. La végétation permet une amélioration de l’activité microbienne mais son rôle dans la rétention et l’élimination des nutriments s’avère mineur au regard des quantités en nutriments apportés. Le sol est le compartiment majeur de rétention du phosphore, même si une saturation rapide du sol en phosphore pourrait limiter cette potentialité. Ces observations ont permis de mettre en évidence une variabilité de l’efficacité des ZTVs dans la rétention de l’eau et des nutriments. Cette variabilité peut d’ores et déjà être minimisée par des mesures d’aménagement et de gestion. L’étude des transferts de nutriments mérite d’être approfondie et étendue à tous les types de ZTV. / The conservation of water quality is a major issue in the 21th century in particular with the increase in the human population. Water-treatment plants rejections represent a risk of pollution of the receiving environment, in particular in nitrogen and phosphorus, with fatal effects for the health and the environment. It is to limit this pollution that the vegetated buffer zones (VBZs), systems of infiltration, where water and nutrients retention are expected, were developed. This study has for main objective to better understand the transfers of nutrients in this type of system. The impact of the various compartments - soil, vegetation, microflora- was studied in two VBZs ditches type, situated downstream to vegetated water-treatment plants in service and in an experimental zone with controlled modalities. This study demonstrated the importance of site hydraulic, soil texture and VBZ surface in effectiveness of water and nutrients retention. The impact of microbial compartment depends largely on the hydraulic retention time bonds to VBZ surface and oxygenation rate of the effluent. Vegetation allows microbial activity improvement but its role in nutrients retention and removal is minor because of high quantities brought by effluents. The soil is the major compartment in phosphorus retention, although a rapid saturation of soil phosphorus could limit this potential. These observations demonstrate variability in the effectiveness of VBZ in water and nutrients retention. This variability could be minimized by planning and management measures. The study of nutrients transfers deserve to be further study and extended to all types of VBZ.

Vegetated roof technologies are increasingly being adopted as treatment measures to mitigate the effects of urban stormwater. A mass balance approach was used to assess the wet weather performance of a vegetated roof on the top of city hall in Waterloo, Ontario. Vegetated and control roof sections were instrumented to measure precipitation inputs, storage and outflow for 18 storm events from June to October, 2006. Concentrations of suspended solids (SS), total phosphorus (TP), soluble reactive phosphorus (SRP), copper (Cu), zinc (Zn), chromium (Cr) and cadmium (Cd) in precipitation and roof (vegetated and control) runoff were measured. A total of 155.6 mm of rain fell during the study period. The vegetated roof retained 64.5 mm (41.5%) of the total rainfall while the control roof retained ~ 5.1 mm (3.3 %). For individual rain events, the vegetated roof retained an average of 3.5 mm (47.6 %) while the control roof retained ~ 0.3 mm (4.7 %). Water retention varied with storm size, season and was influenced by wetting history. The vegetated roof retained 80.6 % of precipitation for light storm events (≤ 3.5 mm) and 34.9 % for large storm events (> 3.5 mm). The control roof retained 7.6 % light storm events and 3.7 % for large storm events. Water quality from the vegetated roof did not show significant improvement as only Zn concentrations in runoff from the vegetated roof were significantly lower than that measured in runoff from the control roof. Concentrations of SS, Cu, Cr and Cd in vegetated roof runoff were relative to concentrations in rainfall and control roof runoff and TP and SRP concentrations were significantly higher than that in rainfall or control roof runoff. Results gained from this study may assist people in planning and stormwater management by providing insight into the monitoring, development and application of new stormwater controls.

Vegetated roof technologies are increasingly being adopted as treatment measures to mitigate the effects of urban stormwater. A mass balance approach was used to assess the wet weather performance of a vegetated roof on the top of city hall in Waterloo, Ontario. Vegetated and control roof sections were instrumented to measure precipitation inputs, storage and outflow for 18 storm events from June to October, 2006. Concentrations of suspended solids (SS), total phosphorus (TP), soluble reactive phosphorus (SRP), copper (Cu), zinc (Zn), chromium (Cr) and cadmium (Cd) in precipitation and roof (vegetated and control) runoff were measured. A total of 155.6 mm of rain fell during the study period. The vegetated roof retained 64.5 mm (41.5%) of the total rainfall while the control roof retained ~ 5.1 mm (3.3 %). For individual rain events, the vegetated roof retained an average of 3.5 mm (47.6 %) while the control roof retained ~ 0.3 mm (4.7 %). Water retention varied with storm size, season and was influenced by wetting history. The vegetated roof retained 80.6 % of precipitation for light storm events (≤ 3.5 mm) and 34.9 % for large storm events (> 3.5 mm). The control roof retained 7.6 % light storm events and 3.7 % for large storm events. Water quality from the vegetated roof did not show significant improvement as only Zn concentrations in runoff from the vegetated roof were significantly lower than that measured in runoff from the control roof. Concentrations of SS, Cu, Cr and Cd in vegetated roof runoff were relative to concentrations in rainfall and control roof runoff and TP and SRP concentrations were significantly higher than that in rainfall or control roof runoff. Results gained from this study may assist people in planning and stormwater management by providing insight into the monitoring, development and application of new stormwater controls.

<p> Reflection and heating coefficients were measured during the 3 month summer season at Simcoe, southern Ontario. Contrasting agricultural surfaces and atmospheric conditions were used to analyse their effect on the reflection and heating coefficients. The results confirm the postulate of Montieth (1959a) that <alpha> is close to 0.25 for many vegetated surfaces. <beta> values were positive and there was a tendency for <beta> to approximate 0.22 for many of the vegetated surfaces. Finally it was shown that the radiation balance equation for Simcoe can be generalized into a linear function of solar radiation using the same constants that are applicable to many areas in the world. </p> / Thesis / Master of Arts (MA)