Jorg Imberger

University of Miami | UM · Rosenstiel School of Marine and Atmospheric Science

Sustainable reservoir-river management requires balancing complex trade-offs and decision-making to support both human water demands and ecological function. Current numerical simulation and optimization algorithms can guide reservoir-river operations for optimal hydropower production, irrigation, nutrient management, and municipal consumption, yet...

This is a contribution to the special issue honoring the late John R. Blake of the University of Birmingham. All three authors had the pleasure of extensive technical interactions with John Blake during his career in the UK, USA and Australia and benefited both professionally and personally from his friendship. John’s work in developing fundamental...

All three authors had the pleasure of extensive technical interactions with John Blake during his career in the UK, USA and Australia and benefited both professionally and personally from his friendship. John’s work in developing fundamental mathematical solutions for Stokes’ flows and his application of those mathematical tools to analyses of micr...

Transport of dense fluid by an inclined gravity current can control the vertical density structure of the receiving basin in many natural and industrial settings. A case familiar to many is a lake fed by river water that is dense relative to the lake water. In laboratory experiments, we pulsed dye into the basin inflow to visualise the transport pa...

Many factors including depth, vegetation density, wind, and gyres may act to influence the littoral exchange in a water body but very few studies have investigated the interaction between more than two of these factors at any time. To investigate these controls on horizontal exchange in a large tropical reservoir, we conducted a 9-d intensive field...

A combination of field observations and 3D hydrodynamic simulations were used to identify the phytoplankton species and to estimate the various time scales of the dominant physical and biological processes in Lake Iseo, a deep subalpine lake located in northern Italy, during a stratified period (July 2010). By ordering the rate processes time scale...

Flows in the upper ocean mixed layer are responsible for the transport and dispersion of biogeochemical tracers, phytoplankton and buoyant pollutants, such as hydrocarbons from an oil spill. Material dispersion in mixed layer flows subject to diurnal buoyancy forcing and weak winds (|u10|=5ms-1) are investigated using a non-hydrostatic model. Both...

Lake Monger (Perth, Western Australia) is a highly eutrophic lake, characterised by very low species richness of macrophytes with the dominance of Potamogeton crispus. Mesocosm experiments were performed using water and plants collected from the lake to determine the effects of vegetation decay on the phosphorus (P) concentrations in the overlying...

Conductivity probe data from laboratory experiments on the evolution of the stratification within a triangular basin due to a turbulent entraining gravity current. See readme.txt and readme_meta_data.txt for detailed information. Please contact Charlie Hogg at chogg@cantab.net for further information or clarification.

In many important natural and industrial systems, gravity currents of dense fluid feed basins. Examples include lakes fed by dense rivers and auditoria supplied with cooled air by ventilation systems. As we will show, the entrainment into such buoyancy driven currents can be influenced by viscous forces. Little work, however, has examined this visc...

A three-dimensional coupled hydrodynamic and ecological model, ELCOM–CAEDYM, was extended to include buoyancy control dynamics for cyanobacteria, and validated in the stratified Daecheong Reservoir (Korea). Specifically, the model was used to explore the physical and biological processes that determined the temporal and spatial variability of Micro...

Three-dimensional hydrodynamic and ecological modelling was used to explore strategies to mitigate the impacts of high biomass algal blooms (Aulacoseira sp.) on the drinking water intakes of the city of Buenos Aires, in the Río de la Plata. An automated real-time and a four-day forecast warning system was implemented in 2010 in order to predict the...

In this chapter, we present a detailed analysis of the annual thermal regime of Lake Kinneret based on high-resolution thermistor chain and meteorological data collected by the Centre for Water Research at the University of Western Australia during the period April 2007–April 2008. Five seasonal regimes of the yearly cycle are defined to illustrate...

The spatial distribution of phytoplankton in the surface waters of a typical, deep subalpine lake was investigated by analysing water samples collected at 3 depth ranges (0-1, 9-13, and 15-19 m) at 7 sites (21 total samples) using a generalized linear model. The biovolume of different phytoplanktonic taxa significantly differed between depth ranges...

An ; ice-formation algorithm is implemented in the three-dimensional Estuary and Lake Computer Model, to allow simulation of hydrodynamics and the thermal structure beneath the ice during winter. The one-dimensional governing equation of heat conduction among the three layers of white ice, blue ice, and snow is solved for the formation of ice cover...

Coupled three-dimensional hydrodynamic and ecological numerical simulations were used to investigate the role of transport, stagnation zones and dispersion on inter-annual blooms of the diatom Aulacoseira sp. in the vicinity of the drinking water intakes of the Buenos Aires city (Argentina) in the upper Río de la Plata. Three different summer event...

The influence of different nutrient sources on the seasonal variation of nutrients and phytoplankton was assessed in the northern area of the Perth coastal margin, south–western Australia. This nearshore area is shallow, semi-enclosed by submerged reefs, oligotrophic, nitrogen-limited and receives sewage effluent via submerged outfalls. Analysis of...

The issue of the transport of dissolved nutrients and contaminants between the sediment in the bottom of a lake or reservoir and the body of water above it is an important one for many reasons. In particular the biological and chemical condition of the body of water is intricately linked to these mass transport processes. As the review by Boudreau...

We use field data and a high-resolution three-dimensional (3D) hydrodynamic numerical model to investigate the horizontal transport and dispersion characteristics in the upper reaches of the shallow Río de la Plata estuary, located between the Argentinean and Uruguayan coasts, with the objective of relating the mixing characteristics to the likelih...

Urban lakes are typically smaller, shallower, and more exposed to human activities than natural lakes. Although the effects of harmful algal blooms (HABs) associated with eutrophication in urban lakes has become a growing concern for water resources management and environmental protection, studies focussing on this topic in relation to urban lakes...

It is widely recognised that southwest Western Australia has experienced a decline in rainfall over the last 40 years. It is generally thought that this decline is due to natural periodic variations and changes induced by global warming, but recently evidence has emerged suggesting that a substantial part of the decline may be due to extensive logg...

The energy transfer from basin-scale internal waves to internal nonlinear waves was investigated in a large, deep subalpine lake through a combination of field data and three-dimensional hydrostatic and nonhydrostatic modeling. The response of the internal wave field induced by two storm events, with distinct characteristics, showed that, for the w...

The Australian state of Western Australia could follow a number of different paths to satisfy its future energy needs with each path meeting different criteria for sustainable development. A number of energy use scenarios were analysed, including the present case of high fossil fuel use, in terms of carbon dioxide emissions, water consumption, and...

Microstructure profiles of velocity and temperature were collected in Lake Kinneret during the summer months of 1997, 1998, 1999 and 2001 using the Portable Flux Profiler. The profiles were analysed to determine the turbulent properties within statistically homogeneous microstructure patches that were identified in each profile. The nature of the t...

River water flowing as an interflow was investigated using field data, collected in Lake Iseo (Italy), and theory. A theory for the lateral falling mechanism of plunging was developed for inflows when the initial densimetric Froude number (Fr-0) is slightly larger than unity. The ratio of the river width to the offshore extent of the plunge region...

1. In order to characterise phytoplankton patchiness at fine scales, a profiling multiwavelength fluorometer was cast at numerous locations throughout Winam Gulf in Lake Victoria to measure fluorescent excitation spectra, which are indicators of both phytoplankton diversity and coloured dissolved organic matter (CDOM). 2. Processing the spectral da...

This textbook is designed to introduce the principles of fluid dynamics to students of environmental and aquatic sciences. Introduces the principles of fluid dynamics, follows with simple applications, and builds to more complex applications experienced in the field. Offers a unique, authoritative, and accessible treatment of the subject. Includes...

Highlights ► A 1D Lagrangian model for Upper and Middle Tiete River Basin is developed. ► The numerical treatment of flow through dams and hydraulic jump is described. ► The model predicts spatial and seasonal variation of flow and temperature well. ► The model can be an ideal tool for river/water management decision making.

The Swan River estuary is an icon of the city of Perth, Western Australia, running through the city centre and dividing the northern from the southern part of the city. However, frequent phytoplankton blooms have been observed in the estuary as a result of eutrophication. The Index of Sustainable Functionality (ISF), a composite index able to indic...

Rapid in situ measurements of some components of fluorescent spectra are now possible with submersible multi-wavelength fluorometers, which implies that phytoplankton composition can be measured, at least implicitly, at a spatial resolution that allows many scales of patches to be resolved. We present a method for identifying the location of patche...

Field data, theoretical analyses, and numerical simulations were used to investigate the effects of lake basin bathymetry and spatial and temporal structures of the wind field on the basin-scale internal wave spectrum in Lake Iseo. This deep Italian basin is characterized by the presence of a large island, imparting attributes of an annulus to the...

This article shows how local knowledge may be valuably integrated into a scientific approach in the study of large and complex hydrological systems where data collection at high resolution is a challenge. This claim is supported through a study of the hydrodynamics of a large lake where qualitative data collected from professional fishers was combi...

The construction of a flood protection structure that obscured views of the lake in Como, northern Italy, led to unprecedented public protest in 2009–2010 and to the eventual dismantlement of the structure. This provided a focus to investigate the delicate interplay of technical and cultural matters in environmental policy—in this case, catchment m...

We measured spatial gradients of dissolved oxygen in a eutrophic reservoir from repeated transects over a 5-day period. The equation typically used to compute lake metabolism was extended to the full advection–diffusion–reaction equation, which includes transport terms. These transport terms were computed and found to be of similar magnitude to the...

Tone River is a shallow, tidal estuary with a controllable upstream freshwater discharge via a barrage. The mixing characteristics in the benthic and interfacial regions of the Tone River estuary were investigated during a time window of maximum freshwater discharge and high shear, using temperature and velocity microstructure measurements. Althoug...

The fate of river water entering a lake remains an uncertainty in many important limnological questions. These questions include how to improve standard water management practices and how lake ecosystems will change in future climate scenarios. This paper describes a field campaign carried out to understand the transport and mixing of a river inlet...

Like most harbors, the Port of Ensenada, Mexico, is vulnerable to the accumulation of pollutants. A wave-driven seawater pump (Sistema de Bombeo por Energía de Oleaje [SIBEO]) is proposed to inject clean and oxygen-rich water from outside the Port to promote flushing in its more stagnant areas. Three-dimensional, numerical simulations with the Estu...

During the past decade there has been growing interest in the hydro-ecology of Kuwait Bay. These concerns have been primarily associated with the expansion of desalination plants, rapid growth in waterfront developments and rising sewage discharges that have caused substantial nutrient increases in the region. Recently, this has lead to increase ec...

The interaction of multiple inflows entering a reservoir (Thomson Reservoir, Australia)is investigated with a field experiment andthree-dimensional numerical model simulations.The focus of the study is the mixing and transport patterns within the reservoir of the inflowing water.Data from the field experiment showed the existence of multiple inflow...

The assimilative capacities of estuaries and coastal seas for effluent discharges are predominantly determined by the rates at which pollutant-bearing effluents are first dispersed and then flushed from the coastal region into the open ocean. The dispersion coefficients and flushing, as measured by the water residence time in the Persian Gulf (Arab...

Lake Burragorang is the largest water supply source for the Sydney region, providing up to 80% of Sydney's water supply. The Index of Sustainable Functionality (ISF) was applied to the geographical domain of its catchment (Warragamba Catchment) for the 20 year period from 1989 to 2008 as a measure of its health and sustainability. The ISF values sh...

In large lakes, temporal variability is compounded by strong spatial variability associated with mesoscale physical processes such as upwelling and basin-scale circulation. Here we explore the ability of a three dimensional model (ELCOM–CAEDYM) to capture temporal and spatial variability of phytoplankton and nutrients in Lake Erie. We emphasized th...

This paper explores the phenomena associated with the emergence of gas bubbles from a submerged granular bed. While there are many natural and industrial applications, we focus on the particular circumstances and consequences associated with the emergence of methane bubbles from the beds of lakes and reservoirs since there are significant implicati...

The index of sustainable functionality (ISF) was applied to assess the impact of the Marina Bay development project on the sustainability of Singapore. The development project has three aims: water supply, flood control and lifestyle attraction; construction for the various stages began in 2005, with scheduled completion end of 2009. The period of...

The energy transfer in a large deep lake, from the largest wind-excited basin-scale waves down to solitary-type waves, was investigated through a combination of inviscid nonlinear modal analysis and numerical simulations on the basis of weakly nonhydrostatic equations for internal gravitational waves. Data from four thermistor chains deployed in La...

Field experiments were conducted to investigate the near-field dilution characteristics of a hypersaline brine discharge into coastal waters via an offshore diffuser from a desalination plant. The aim was to determine the dilution of the negatively buoyant plume as it exited the diffuser under three different discharge Froude number regimes (one-th...

The temporal and spatial variations of pCO2 in the ocean surface layer in response to the passage of Hurricane Frances (2004) were investigated with a coupled three-dimensional hydrodynamic and carbon model. The results showed that the sea surface temperature cooling was the dominant cause of the decrease of surface pCO2, while the entrainment of w...

Coastal waters have always been important for society because of their effective role in transportation and water supply, while being used as a means of disposal of treated or untreated wastewater. They also provide eco-system resources of immense significance to the challenges of climate change etc. During recent decades many scientists and engine...

Several large rivers enter Winam Gulf, a large shallow semi-enclosed embayment of Lake Victoria. Given the vast spatial scale of this embayment (1400 km(2)), horizontal transport of waterborne material plays a major role in determining its biochemical properties. To identify the dominant hydrodynamic characteristics of this horizontal transport, a...

The Index of Sustainable Functionality makes it possible to analyse the sustainability of multiple systems within a domain from various perspectives. To illustrate how changes to wealth distribution since 1980 can impact sustainability of the economy, environment and society, the resource rich state of Western Australia’s sustainable functionality...

A combined stream function is derived for investigating horizontal dispersion of pollutants in a moderate-sized circular rotating basin when internal wave and gyre flow field coexist in the upper mixing layer. The combined flow field is analogous to wave-current flow in which the steady part is the depthwise velocity profile of circumferential gyre...

In this study, a one-dimensional model called DYRESM was used to simulate the thermal structure and artificial destratification of 15-Khordad Reservoir over a period of one year. The simulation showed that the reservoir is warm monomictic and is stratified during 210 days of the simulation year. The model reproduced the temperature of the meta- and...

Lake Como receives inflows of vastly varying scales. The majority of the lake's water comes from the alpine inflows to the north, and much smaller inflows supply large amounts of pollutants in the south. We combined various data sets with a three-dimensional hydrodynamic model to investigate the processes affecting the fate of these inflows with po...

The effect of lake geometry on wind-induced upwelling, in a two-layer stratified lake with a variable bottom slope and generic planar shape is investigated. (1) The traditional linearized classification parameter for upwelling, the Wedderburn number, is extended to include finite amplitude effects in a rectangular basin; this extension is important...

The three-dimensional hydrodynamic Estuary, Lake and Coastal Ocean Model (ELCOM) was coupled to the ecological Computational Aquatic Ecosystem Dynamics Model (CAEDYM) and to an underflow model to simulate the fate of the constituents from three flood underflow events in Lake Burragorang, Australia, in order to verify the changes in the hydrodynamic...

The evolution of damped basin-scale internal waves was investigated using a modal analysis for layer-stratified rotating lakes. A simple model for homogeneous oscillatory boundary layers was incorporated into the modal analysis to predict damping rates of individual internal-wave modes, enabling the prediction of their evolution under wind forcing...

We describe the residual circulation induced in a two-layer system when internal waves, with a wave length equal to or longer than the slope length, propagate over a sloping bottom and either reflect or break. For the case of no wave breaking, scaling is used to derive Boussinesq-type equations, the solution of which leads to an expression for the...

Field data, collected in a shallow underflow into a medium-sized reservoir, show that the dimensionless entrainment, E, is non-negligible at high Richardson numbers. For such underflow, the field data demonstrate that E is mainly dependent on the stress generated at the bottom, directly determined by the relative bed roughness and the properties of...

Several field and numerical methods were applied to a stratified, freshwater reservoir to characterise the horizontal flow field and investigate the horizontal dispersion driven by the dominant circulation patterns. The horizontal motions observed in the surface layer included oscillatory motions associated with two basin-scale internal wave modes,...

Horizontal dispersion mechanisms must be well defined in order to determine the origin and fate of heterogeneous distributions of biogeochemical material. Here data from an intensive field campaign in Valle de Bravo Reservoir, Mexico, was used to run a three‐dimensional hydrodynamic model, and the simulated flow field was used to characterize the h...

Heat and turbulent kinetic energy budgets of the ocean surface layer during the passage of Hurricane Frances were examined using a three-dimensional hydrodynamic model. In situ data obtained with the Electromagnetic-Autonomous Profiling Explorer (EM-APEX) floats were used to set up the initial conditions of the model simulation and to compare to th...

1] The paper describes the effect of a stair-step representation of bottom topography, common in most numerical models, on the propagation of internal waves in a geophysical flow. An analytical solution was used to predict the effect of stair-step and piecewise linear representations of topography on the reflection and transmission of internal wave...

Many reservoirs and associated downstream ecosystems located in the Asian monsoon climate region are under increased pressure from the long-term negative effects of turbid flood runoff. Despite the ubiquitous use of turbidity (CT) as a barometer of water quality and environmental “health”, CT modelling studies have been rare due to lack of detailed...

Physical characteristics of a hypolimnetic oxygenator known as a Water Environmental Preservation System (WEP), were investigated through field tests carried out in Sanbe Reservoir, Japan. Field data showed that the oxygen‐rich intrusion traveled at nearly the same height as the outflow opening of the device. The thickness of the intrusion, travel...

A fully Lagrangian method is presented for the accurate simulation of advection-diffusion transport in both steady and unsteady open channel flows. Numerical results are presented for Gaussian tracer distributions, top hat tracer distributions, and steep tracer fronts (step function) profiles in a uniform flow and are compared against analytical so...

A Lagrangian, nonhydrostatic, Boussinesq model for weakly nonlinear and weakly dispersive flow is presented. The model is an extension of the hydrostatic model-dynamic river model. The model uses a second-order, staggered grid, predictor-corrector scheme with a fractional step method for the computation of the nonhydrostatic pressure. Numerical res...

Damping mechanisms, damping rates and the dissipative modal structure of internal waves in stratified rotating circular basins are investigated analytically. The damping is shown to be due to a combination of the internal-wave cancelling, where waves emitted by the oscillatory boundary layers destructively interact with the parent wave and drain en...

A new Lagrangian, dynamic river model is described. The model solves the coupled one-dimensional hydrostatic flow equations separately in a main river channel and in adjacent floodplains using a two-stage predictor-corrector scheme. The lateral interaction between the main channel and floodplains, due to both advective exchange arising from lateral...

The feasibility of using a vertically downward pointing impeller to remove polluted water from a coastal margin was investigated with a pilot experiment in Lake Como, Italy. The vertical jet induced by the impeller entrained surface water downward to depth, where upon reaching neutral buoyancy it intruded horizontally into the lake proper. A three-...

The relatively low biodiversity and simple hydrodynamics make solar salt ponds ideal sites for ecological studies. We have studied the ecological gradient of the primary ponds at the Shark Bay Resources solar salt ponds, Western Australia, using a coupled hydrodynamic ecological numerical model, DYRESM–CAEDYM. Seven ponds representative of the prim...

Hydrostatic and non-hydrostatic models were used to simulate the generation of internal surges and associated soliton-like trailing waves from the non-linear steepening of low-frequency basin-scale waves. Results confirmed that the process cannot be modelled using the hydrostatic approximation. A grid-switching strategy was developed to reduce the...

In the last decades, rapid improvement in processor speed has encouraged the development of large, distributed, process-based models, which are implemented in more and more complex computer codes. However, despite the increased computing power, the use of such models is far from being inexpensive: obtaining output trajectories over a time horizon o...

The Aquatic Real-time Management System (ARMS), which incorporates data acquisition, data visualization and, 3D hydrodynamic modelling was used to optimise field sampling and run scenario forecasting as part of a comprehensive limnological study of Thomson Reservoir, the largest storage in the Melbourne Water supply system (Victoria, Australia). Th...

Barbamarco Lagoon is a small lagoon adjoining the Northern Adriatic Sea and is the site of a commercially valuable clam (Tapes philippinarum) fishery. A three-dimensional (3D) coupled hydrodynamic–ecological model was applied to the lagoon with the objective of assessing impacts on clam food supply, commercial harvests and water quality of differen...

The interaction of two rivers flowing into Coeur d'Alene Lake (United States) was investigated with a field experiment and three-dimensional numerical simulations. The focus was on the influence of basin morphology, wind speed, and wind direction on the fate and transport of the inflowing water. Data from the field campaign showed that intrusions f...

Phytoplankton concentration in Lake Kinneret (Israel) has varied up to 10-fold in space and time, with horizontal patches ranging from a couple of kilometres to a basin scale. Previous studies have used a 1D model to reproduce the temporal evolution of physical and biogeochemical variables in this lake. The question that arises then is how appropri...

Changes in the spatial distribution of the dinoflagellate Ceratium hirundinella were observed in a stratified, medium-sized (16 km 2) Argentinean reservoir over several days. A fluorescence profiling technique was used to identify persistent patchiness in the distribution of the dinoflagellate. A three-dimensional numerical model was used to reconc...

Results are presented from a laboratory investigation of a continuous discharge gravity current moving down an inclined plane into a linearly stratified fluid; the density of the inflow decreasing linearly with time, initially larger and finally smaller than the bottom ambient density. The inflowing water was observed to follow both underflowing an...

The significance of the transport of nutrient-rich hypolimnetic water via the benthic boundary layer (BBL) to the productivity of Mono Lake was studied using a coupled hydrodynamic and ecological model validated against field data. The coupled model enabled us to differentiate between the role of biotic components and hydrodynamic forcing on the in...

Results from a three-dimensional hydrodynamic model of a stratified lake show that the computed structure of the pycnocline changed rapidly due to numerical diffusion, thus altering the vertical mixing dynamics and introducing a positive feedback that quickly drives model predictions off course. To negate the numerical diffusion a pycnocline filter...

A finite difference inverse method was applied to time-dependent two-dimensional tracer fields from a long narrow water supply reservoir to obtain time-averaged estimates of horizontal and vertical velocities and vertical eddy diffusivities. By comparison to direct measurements, the inverse method successfully resolved the complex flow field observ...

Energetics and damping of basin-scale internal waves and subsequent near-bottom transport processes in Lake Kinneret were investigated using the modal analysis in a layer-stratified irregular basin. The theory was extended to include small linear damping, and energy budgets and damping rates of five dominant internal waves were extracted by fitting...

The influence of inertia and drag on modelled drifter movement is investigated through comparisons of field-observed drifter paths within Marmion Marine Park, Western Australia and those simulated using the Estuary and Lake Computer Model (ELCOM). Simulated drifter paths were generated with existing Lagrangian and leeway modelling techniques, as we...