Marcelo García

Followers

Following

Co-authors

Public Views

Uploads

Papers by Marcelo García

Roughness function for alluvial rivers with dunes

Taylor & Francis eBooks, Aug 2, 2006

Alluvial Roughness in Streams with Dunes: A Boundary-Layer Approach

River, Coastal and Estuarine Morphodynamics, 2001

3 Alluvial Roughness in Streams with Dunes: A Boundary-Layer Approach Juan J. Fedele and Marcelo ... more

Development of Closed-Conduit Roughness

Hydraulic Measurements and Experimental Methods 2002, 2002

Alluvial Resistance and Sediment Transport for Flows over Dunes

Building Partnerships, 2000

The role of dunes in flow resistance in a large and a small river. The case of the Paraná and Tercero rivers, Argentina

Journal of Hydraulic Research, Jan 10, 2022

The dynamics of sandy rivers is a complex phenomenon linking the interactions between dunes, flow... more The dynamics of sandy rivers is a complex phenomenon linking the interactions between dunes, flow and sediment transport. Despite an existing large amount of research, few comparative studies exist for rivers with major hydro-sedimentological differences. This work uses detailed dune measurements from the Paraná and Tercero rivers, Argentina. Significant differences were found in the representative roughness height scale, dune steepness, lee angles, velocity profiles and flow recirculation. It is found that whereas the hydraulic resistance for the Tercero River scales with the size of large dunes, the Paraná River needs to develop an intermediate roughness scale (the small superimposed dunes) to accommodate the required balance between gravity and friction. Suspended bed sediment increase is inversely related to the dune steepness and lee side angles as advanced by previous findings. The suspension number seems to be a paramount metric that helps explain differences regarding dune geometry within a wide range of flow conditions.

Impact of diagenetic alteration on travertine crystalline shrubs, biofilm laminae and ripple marks in the anio novus aqueduct of Ancient Rome

Geological Society of America, Oct 1, 2021

Computational River, Coastal and Delta Hydrodynamics and Morphodynamics

Soil erosion and sedimentation is a continuing problem with far-reaching consequences. There is a... more Soil erosion and sedimentation is a continuing problem with far-reaching consequences. There is a clear need to develop better tools and resources for evaluating spatial and temporal discontinuities in runoff and sediment supply at a range of scales; this information is essential for evaluating land-based fluxes of water, sediment and carbon to the oceans. Given presentday computer capabilities for processing spatially explicit data sets on surface-water hydrology, topography and soils, river hydrodynamics and sediment transport, we are uniquely positioned to address the question of what factors affect regional patterns of erosion and sediment yield as well as how sedimentation affects deltas and coastal areas where millions of people leave around the world. This MS hopes to attract computational modeling papers addressing the following topics: Sediment transport mechanics Alluvial rivers, deltas, estuaries, bays Responses of river and estuaries to floods and storms The impact of ca...

Download

Illinois Conveyance Analysis Program (ICAP)

Understanding the conveyance of sewer networks is vital, especially in cases of great variability... more Understanding the conveyance of sewer networks is vital, especially in cases of great variability in flow rates, such as in combined sanitary and storm sewer systems. Conventional conveyance studies in sewer systems often have extended computation times due to complexity of the solution, or alternatively make assumptions that ignore the water-surface profile within a pipe. In previous research, the hydraulic performance graph (HPG) was successfully used for open-channel capacity determination. The HPG summarizes the results of many backwater calculations for a reach so that these calculations do not need to be repeated. The Illinois Conveyance Analysis Program uses the HPGs to describe the conveyance of a system, identify bottlenecks for varying conditions, conserve mass by tracking outflow and overflows under stepwise steady flow conditions.Ope

Depositional and Diagenetic History of Travertine Deposited Within the Anio Novus Aqueduct of Ancient Rome

Geological Society of America Abstracts with Programs, 2021

Evaluation of the potential for hysteresis in index-velocity ratings for the Chicago Sanitary and Ship Canal near Lemont, Illinois

Scientific Investigations Report, 2013

The U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago Sanitary and... more The U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago Sanitary and Ship Canal (CSSC) near Lemont, Illinois, as a part of the Lake Michigan Diversion Accounting overseen by the U.S. Army Corps of Engineers, Chicago District. Lake Michigan Diversion Accounting is mandated by a U.S. Supreme Court decree in order to monitor, and limit, the State of Illinois' annual diversion of Great Lakes water through the manmade CSSC. Every 5 years, a technical review committee consisting of practicing engineers and academics reviews USGS streamgaging practices in the CSSC near Lemont, Illinois. The sixth technical review committee expressed concern that the index-velocity rating-the method used to estimate mean cross-sectional velocity from a measured index velocity-may be subject to hysteresis at this site because of the unique, unsteady hydraulics of the canal. Hysteresis in index-velocity ratings can occur at sites where the flow distribution in the channel varies significantly between the rising and falling limbs of the hydrograph for the same discharge. Presently, hysteresis in index-velocity ratings has been documented only in tidally affected sites. This report investigates whether hysteresis can occur at this nontidal site, and the conditions under which it is likely to occur, by using both a theoretical approach and a three-dimensional hydrodynamic model. The theoretical analysis investigated the conditions required for hysteresis in the index-velocity rating, and the modeling analysis focused on the effect of the timing of the inflows from the CSSC and the Cal-Sag Channel on the potential for hysteresis and whether highly resolved simulations of actual high-flow events show any evidence of hysteresis. Based on both a theoretical analysis using observed historical data and an analysis using a three-dimensional hydrodynamic model, there is no conclusive evidence for the existence of hysteresis in the index-velocity rating at the USGS streamgage on the CSSC near Lemont, Illinois. Although the theoretical analysis indicated the possibility of hysteresis at this site, the hydrodynamic conditions required to generate hysteresis are not present at this site based on historical data. Ongoing streamgaging practices at this site will use the information in this report and include periodic assessment of the index-velocity rating for any signs of hysteresis that might result from future changes to the operation of this manmade canal.

Download

Curves, Confluences, and Cutoffs: Morphodynamic Insights from the Wabash River

Improved understanding of combined sewer systems using the Illinois Conveyance Analysis Program (ICAP)

Urban Water Journal, 2017

Download

Hydraulic Evaluation of the Design and Operation of Ancient Rome's Anio Novus Aqueduct

Archaeometry, 2017

This paper evaluates conveyance and flow characteristics for the Anio Novus, the aqueduct bringin... more This paper evaluates conveyance and flow characteristics for the Anio Novus, the aqueduct bringing water from the greatest distance to ancient Rome. Travertine accumulations, deposited from water on floor and walls, were used to reconstruct the flow rate and associated spatial and temporal variations. Hydraulic quantities (e.g., flow depth and velocity) markedly varied over the course of the aqueduct, implying that constraints such as topography and construction techniques were combined with hydraulic considerations to determine the aqueduct layout. Design practices differed along the aqueduct and channel size design was not based exclusively on anticipated carrying capacity, tending towards larger‐than‐necessary design based on experience.

Download

Illinois Transient Model: Simulating the Flow Dynamics in Combined Storm Sewer Systems

Journal of Water Management Modeling, 2011

This chapter describes the capabilities and features of the recently developed Illinois transient... more This chapter describes the capabilities and features of the recently developed Illinois transient model (ITM) for simulating the flow dynamics (transient and non-transient conditions) in combined storm sewer systems, ranging from dry bed flows, to gravity flows, to partly gravity-partly surcharged flows (mixed flows), to fully pressurized flows (water hammer flows). ITM, which was originally developed at the University of Illinois at Urbana-Champaign, is a finite volume (FV) model that can handle complex boundary conditions such as drop shafts, reservoirs, closing and opening of gates as a function of time, and junctions with any number of connecting pipes and any types of horizontal and vertical alignment. ITM is open source code that is in constant development and its releases are made available on a regular basis. In the current version of ITM (v. 1.3, September 2010), the free surface region is modeled using the one dimensional (1-D) Saint-Venant equations. The pressurized region is modeled using the 1-D compressible water hammer equations. Open channel-pressurized flow (mixed flow) interfaces are modeled by enforcing mass, momentum and energy relations across the interfaces together with Riemann solvers at the sides of mixed flow interfaces. This version of ITM is referred to as the two equation model. The current version of ITM is superior to other models of its kind because it is robust, can simulate mixed flows (simultaneous occurrence of free surface and pressurized flows) when using actual pressure wave celerities (~1 000 m/s), and because no Preissmann slot assumption is made to simulate pressurized flows (water hammer flows). ITM has been applied to

Download

Hydrologic-Hydraulic Model for Simulating Dual Drainage and Flooding in Urban Areas: Application to a Catchment in the Metropolitan Area of Chicago

Journal of Hydrologic Engineering, 2015

A 1D hydrologic-hydraulic model for simulating dual drainage in urban areas is presented. It cons... more A 1D hydrologic-hydraulic model for simulating dual drainage in urban areas is presented. It consists of four modules: (1) rainfall-runoff transformation, (2) one-dimensional (1-D) flow routing on a street network, (3) flow interception at street inlets and (4) flow interaction between surface water on the streets and the underground storm-water system by interfacing with the EPA-SWMM5 engine (Environmental Protection Agency-Storm Water Management Model). The hydrologic model (first module) transforms rainfall to runoff using the kinematic wave approximation and simulates the infiltration process with the Green-Ampt method. The street network model (second module) is based on a finite-volume shock-capturing scheme that solves the fully conservative Saint-Venant equations and can be used to model both subcritical and supercritical flows. The inlet model (third module) uses the HEC-22 relations to compute the amount of water intercepted by inlets. The formulation of boundary conditions at the street crossings is generalized and can be used for any number of streets, any combination of inflowing and outflowing streets, and flow regime (e.g., subcritical and supercritical flows). Flow interaction between surface water on the streets and underground storm-water system is achieved by interfacing the proposed model with EPA-SWMM5. This interaction allows flow to enter from streets to the underground storm-water system and vice versa. The proposed model has several potential applications such as the identification of critical zones for flooding (e.g., zones with high water depths and flow velocities) in urban developments and can be used to take appropriate measures for drainage control (e.g., to increase number and/or size of inlets), to determine the consequences of different degrees of inlet clogging, and to assess flooding hazards through the application of suitable hazard criteria. A summary of criteria used for storm-water hazard assessment is presented. To demonstrate the dual-drainage model's potential an application is performed in a catchment of the metropolitan area of Chicago, IL. The results obtained are promising and show that the model can be a useful tool for storm water management and flooding hazard assessment in urban areas.

Download

Laboratory Experiments on Pool-Riffle Sequences Designed to Restore Channelized Low-Gradient Streams

Protection and Restoration of Urban and Rural Streams, 2004

This paper presents laboratory experiments on pool-riffle sequences designed to provide 3D veloci... more This paper presents laboratory experiments on pool-riffle sequences designed to provide 3D velocity data of high-resolution -in space and time- for different flow conditions, in order to analyze the implications for the physical habitat in low-gradient streams. Two different configurations were studied. The first one has the pools located on the channel centerline, in an effort to minimize the possibility of scour near the banks. This design is suitable for restoring streams in heavily urbanized areas, where the channel planform alignment is constrained by the existing infrastructure and bank erosion is unacceptable. The second configuration is more representative of natural pool-riffle sequences, with alternated pools located close to the banks. Both configurations where compared with data on flat bed uniform flow.

Flow structure in submarine meandering channels, a continuous discussion on secondary flow

ABSTRACT The understanding of the flow structure in deep-sea turbidity currents is important for ... more ABSTRACT The understanding of the flow structure in deep-sea turbidity currents is important for the formation of submarine meandering channels. Similarly to the case of subaerial channels, several types of secondary flows include turbulence-, curvature- and bed morphodynamic-driven flow structures that modulate sediment transport and channel bed morphodynamics. This study focuses on [1] a review of long-time research effort (Abad et al., 2011) that tackles the description of the secondary flow associated with a subaqueous bottom current (saline) in a high-curvature meandering channel and [2] ongoing numerical simulations of similar settings as the experiments to describe the entire flow structure. In the case of subaerial channels, the classical Rozovskiian paradigm is often invoked which indicates that the near-bottom secondary flow in a bend is directed inward. It has recently been suggested based on experimental and theoretical considerations, however, that this pattern is reversed (near-bottom secondary flow is directed outward) in the case of submarine meandering channels. Experimental results presented here, on the other hand, indicate near-bottom secondary flows that have the same direction as observed in a river (normal secondary flow). The implication is an apparent contradiction between experimental results. This study combines theory, experiments, reconstructions of field flows and ongoing simulations to resolve this apparent contradiction based on the flow densimetric Froude number. Three ranges of densimetric Froude number are found, such that a) in an upper regime, secondary flow is reversed, b) in a middle regime, it is normal and c) in a lower regime, it is reversed. These results are applied to field scale channel-forming turbidity currents in the Amazon submarine canyon-fan system (Amazon Channel) and the Monterey canyon and a saline underflow in the Black Sea flowing from the Bosphorus. Our analysis indicates that secondary flow should be normal throughout most of the Amazon submarine fan reach, lower-regime reversed in the case of the Black Sea underflow, and upper-regime reversed in the case of the Monterey canyon. The analysis predicts both normal and reversed regimes in the Amazon submarine canyon reach. This research presents insights on the importance of flow structure not only to describe subaqueous bed morphodynamics, but also to understand evolution of submarine meandering channels, therefore its importance for developing accurate morphodynamic models. Reference: Abad, J. D., Sequeiros, O. E., Spinewine, B., Pirmez, C., Garcia, M. H., Parker, G. (2011). SECONDARY CURRENT OF SALINE UNDERFLOW IN A HIGHLY MEANDERING CHANNEL: EXPERIMENTS AND THEORY. In press, Journal of Sedimentary Research

Hydraulic model study of a canoe chute for low-head dams in Illinois

In recent decades, there has been an increase in recreation on Illinois rivers and streams. Canoe... more In recent decades, there has been an increase in recreation on Illinois rivers and streams. Canoeing and kayaking are two of the activities that have become more popular. On many Illinois rivers there are low-head dams that are a hazard to canoeists and kayakers. Structures such as canoe chutes are necessary at dams to provide safe passage for boaters. Although, many structures for kayak passage have been built at low-head dams in the western United States, few definite design guidelines for canoe chutes are present in the literature. Therefore, it has been necessary to do a physical model study for all or most of the existing structures. Physical modeling is expensive in both time and money. With the aim of eventually constructing canoe chutes at low-head dams in Illinois, the Illinois Department of Natural Resources asked the Department of Civil and Environmental Engineering at the University of Illinois to conduct a study of canoe chutes. The aims of the study were to understand more fully the three-dimensional flow in canoe chutes and to develop design guidelines for canoe chutes in Illinois. As with previous studies on canoe chutes, a physical model of a canoe chute was built. However, to save time and money, numerical tests using the program, Flow-3D, were done on several design possibilities. The numerical tests were compared to the results fiom the physical model. An analysis of the canoe chute using two-dimensional momentum equations was performed in order to gain a fuller understanding of the flow in canoe chutes. Additionally, an empirical method was developed for predicting hydraulic jump behavior in canoe chutes. This method is important for applying the design guideline that only wave-type hydraulic jumps are safe in canoe chutes.

Download

Three-dimensional hydrodynamic modeling of density currents in the Chicago River, Illinois

The potential development of density currents in the Chicago River has been analyzed with the hel... more The potential development of density currents in the Chicago River has been analyzed with the help of a three-dimensional hydrodynamic model. It was found that during the winter months, density currents can develop at the junction of the Chicago River with its North and South Branches. Such density underflows show a clear tendency to flow from the junction towards Lake Michigan. Through this subtle phenomenon, density currents are able to transport water of lesser quality along the bottom towards Lake Michigan. This phenomenon clearly explains the observations of bi-directional flow conditions made by the U.S. Geological Survey at Columbus Drive and other cross sections in the Chicago River. While this study shows that density current activity in the Chicago River is very likely, the frequency, duration, and flow discharges associated with this phenomenon have yet to be determined.

Download

A Robust and Fast Model for Simulating Street Flooding

World Environmental and Water Resources Congress 2009, 2009

Abstract This work is part of a long term project which aims to simulate (1) the hydrology,(2) st... more Abstract This work is part of a long term project which aims to simulate (1) the hydrology,(2) street flows,(3) flow interception at inlets and (4) storm-sewer flows in urban areas. The present work describes the application of the model using only the first two modules. The hydrologic model (first module) transforms rainfall to runoff using the kinematic wave approximation and simulating the infiltration process with the Green-Ampt method. The street model (second module) is based on a finite volume-shock capturing scheme that ...

Marcelo García

Uploads

Papers by Marcelo García

Log In