Environmental Engineering Commons^™

Erosion Control Of Steep Open Channels Using Articulated Concrete Blocks, Mohammadomid Marandi

Electronic Thesis and Dissertation Repository

Overtopping flow can undermine the stability of hydraulic structures including embankments and spillways through the shear stress and the subsequent soil erosion. Increased flow velocity can cause scour, which can result in the failure of dams, bridges, and overall open channel hydraulic structures. Sediment transport is another crucial issue in open channels that can cause severe socioeconomic and environmental consequences. Two general approaches are commonly considered for scour prevention. The first approach involves flow modifications to minimize the corresponding effects on the structures. The second approach is associated with bed armoring and placing physical barriers on the natural bedding such …

Future Changes Of Hydroclimatic Extremes In Western North America Using A Large Ensemble: The Role Of Internal Variability, Mohammad Hasan Mahmoudi

Electronic Thesis and Dissertation Repository

Increases in the intensity and frequency of extreme events in Western North America (WNA) can cause significant socioeconomic problems and threaten existing infrastructure. In this study we analyze the impacts of climate change on hydroclimatic extremes and assess the role of internal variability over WNA, which collectively drain an area of about 1 million km². We used gridded observations and downscaled precipitation, maximum and minimum temperature from seven General Circulation Models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a large ensemble of CanESM2 model simulations (CanESM2-LE; 50 members) for this analysis. Spatial …

Modeling Of Suspended Sediment Concentration Using Conventional And Machine Learning Approaches, In Thames River, Canada, Issam Mohamed

Electronic Thesis and Dissertation Repository

Water resource management, planning, hydraulic design, environmental conservation, reservoir management and operation all require reliable information and data about Suspended Sediment Concentration (SSC). To predict such data, direct sampling and Sediment Rating Curves (SRC) are commonly utilized. Since direct sampling can be risky during extreme weather events and SRC cannot provide satisfactorily dependable results, engineers are trying to propose new precise fore-casting approaches. Various soft computing techniques have been applied to model different hydrological and environmental problems and have showed promising results in this regard. Although many studies have been performed to simulate the phenomena of SSC at numerous rivers …

Modelling Of Future Flood Risk Across Canada Under Climate Change, Ayushi Gaur

Electronic Thesis and Dissertation Repository

Climate change has induced changes in key climate variables and hydrological cycle in Canada. In this study, future runoff projections made by 21 GCMs following four Representative Concentration Pathways (RCPs) are used as inputs into a macro-scaled hydrodynamic model: CaMa-Flood to simulate 25 km resolution daily streamflow across Canada for historical (1961-2005) and future (2061-2100) time-periods. Future changes in flood-hazard as a consequence of changes in flooding frequencies of historical 100-year and 250-year return period flood events, and changes in the month of occurrence of extreme flows are analyzed. Changes in flood risk at Canada’s 100 most populous cities and …

Morphological Response Of Sand Bed Streams To Unsteady Flow Events: An Experimental Study, Etta Haley Gunsolus

Electronic Thesis and Dissertation Repository

Changes in riverine discharge, such as those due to reservoir flushing, seasonal variation or extreme precipitation events, can alter sediment transport rates and morphology of the stream bed. Experimental research investigated the effect of unsteady flow event hydrographs on stream bed morphological response. Laboratory experiments were conducted in a 5.0 m-long sediment transport flume with a bed comprised of a medium sand. Experimental hydrographs were composed of antecedent (base-flow), unsteady event (flood) and post- flood (return to base-flow) stages. Three distinct series of experimental laboratory runs were conducted to systematically investigate the effect of three characteristics of unsteady flow event …

Characterization Of The Green Roof Growth Media, Ginevra Alessandra Perelli

Electronic Thesis and Dissertation Repository

Green roofs are becoming a popular solution to manage the stormwater, to reduce the energy consumption in highly urbanized environment and provide many additional benefits. One of the key components that characterize the green roof system is the growth medium; the medium supports the plants, providing water and nutrient storage, and contributes to the roof insulation.

The object of this thesis is to investigate the hydraulic and the thermal properties of the green roof growth medium and to study the relationship among these properties through extensive laboratory analyses. In addition, the laboratory results are compared with direct measurements in the …

Study Of Vertical Dense Jet Dilution In A Marine Environment, Nadeem Ahmad

Electronic Thesis and Dissertation Repository

Brine is a byproduct of many industrial and mining processes, including desalination. Brine is commonly conveyed in long pipe lines and disposed in the bottom of the sea through multiport diffusers, forming dense jets, also known as fountains. An acceptable level of brine concentration is required to be achieved at the boundary of a regulatory mixing zone surrounding a point of discharge. Such mixing zones are allocated with the objective of limiting environmental deterioration within their boundaries. Mixing zones are, nevertheless, not allowed when discharging brine in sensitive areas and when brine is toxic.

The main contribution of this study …

Analytical And Experimental Study Of A Three Dimensional Internal Hydraulic Jump In A Shallow Channel Of Limited Width, Zoheb Nasir

Electronic Thesis and Dissertation Repository

The main objective of this thesis is to study the hydraulic behaviour of a surface heated discharge in a shallow channel, which is wider than the discharge of thermal waste, and connected to a colder water body. An internal hydraulic jump characterized by mixing (dilution) of hot and cold water was observed in the channel. Similar to the single-layer hydraulic jump, the internal hydraulic jump in a two-layer system is a rapid transition from supercritical to subcritical flow.

The study involved analytical and experimental analyses of the flow in the channel. The analytical analysis showed that the critical dilution initially …

Application Of A K-Nearest Neighbour Weather Generator For Simulation Of Historical And Future Climate Variables In The Upper Thames River Basin, Leanna M. King

Electronic Thesis and Dissertation Repository

Climate change has the potential to significantly alter the hydrologic cycle, changing the frequency and intensity of precipitation events in an area. It is necessary to quantify these effects to effectively manage water resources in the future. Atmosphere-Ocean coupled Global Circulation Models (AOGCMs), often used in climate change research, have spatial resolutions that are too large to capture the local climate characteristics of a watershed. As a result, several downscaling tools have been developed, including stochastic weather generators. A methodology for the simulation of historical and future climate data using a nonparametric K-Nearest Neighbour block resampling weather generator with perturbation …