| John England Noah Friesen James Halgren Dohyuk Kang |
Youngho Shin Mark Velleux Chad Vensel Mark R Weinhold |
| John England Noah Friesen James Halgren Dohyuk Kang |
Youngho Shin Mark Velleux Chad Vensel Mark R Weinhold |
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Estimates
of extreme floods and
probabilities are needed for hydrologic engineering and dam safety risk
analysis. Physically-based, distributed watershed models are
used
as an avenue to estimate extreme floods, and as a basis to extrapolate
frequency curves. This research focuses on applied
hydrology
and
hydraulics of extreme floods on large
watersheds. The main
elements of this  research
include improving and
using a
two-dimensional, physically-based rainfall-runoff model (CASC2D) to
estimate extr
eme
floods and probabilities for
dam safety on a large (12,000 km2) watershed, the Arkansas River above
Pueblo, Colorado. New tools have been
developed, including a
channel mesh generator, so the model can be applied at this
scale. The main research goals are to: demonstrate that
CASC2D
can be used to simulate extreme floods on large watersheds; and add new
process components, including extreme storms and initial conditions, so
that CASC2D can be used to develop a flood frequency curve.
In
addition, we are conducting sensitivity studies to examine: the spatial
distribution of storm rainfall with area and elevation; storm duration;
initial soil saturation; and channel floodplains; and their effects on
the model flood frequency curve extrapolation, hydrograph shape,
timing, peak and volume.CASC2D is appropriate for simulating extreme floods and physically-based extrapolations of frequency relationships, combined with a derived distribution approach. CASC2D can be successfully used to model extreme floods based on observations of extreme rainfall (from both rain gage networks and weather radar) for large watersheds. Images show the Arkansas River Watershed DEM for CASC2D, and predicted water depths for the watershed. Ongoing research focuses on the storm transposition concept and linkages with radar. |
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| Noah Friesen is a
Masters student in the hydraulics and river mechanics program at CSU.
After getting a BS in Civil Engineering in 2005 from CSU, he returned
for graduate school in the spring of 2006. He spent the summer of 2006
in Las Vegas, Nevada working at the Desert Research Institute, which is
the research branch of the University of Nevada system. He worked with Dr. Jennifer Duan on a project funded by the Army Corps of Engineers. The Las Vegas valley is extensively urbanized, but has little natural drainage. 
Although the region is extremely dry, storms
that do occur can be very intense and of short duration. Also, the
close proximity of mountains creates alluvial fans that increase the
runoff from a storm even more. This results in high discharge,
high
velocity flows through the city. To help control this flow, a network
of concrete drainage channels has been built. These channels are either
rectangular or trapezoidal around 3-4 meters wide. The slopes range
from 1 to 4 percent. Thus during high flows the flow enters the
supercritical regime, with Froude numbers up to 4. The work that he has
done is based on a theoretical analysis of unsteady flow at
supercritical velocities. Noah is looking at
wave height and celerity for
different conditions to help draft design guidelines for the
construction of the drainage channels. Adding freeboard on top of
design flow depths can significantly increase the cost of a channel,
and so a more exact idea of how much freeboard is needed would be
helpful. |
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Un Ji is a PhD student of the hydraulic engineering program in Civil Engineering at Colorado State University (CSU) and she came from Korea. She graduated from Myoungji University in Korea with a BS and MS degrees in Civil and Environment Engineering. In Korea, she worked for several research projects, during the graduate course, such as the experimental and numerical studies and field works related to hydraulics, hydrology and water management. Also, she has been studying the sediment transport, river mechanics, river rehabilitation, fluvial geomorphology etc in the hydraulic engineering program at CSU.  The Nakdong River in South Korea has a basin area of 23,326 km2 and the estuary barrage is located at the end of the river to reduce salt-water 
intrusion in the estuary and prevent a large flood due to high tides.
The channel of Nakdong River was designed to convey a design flood of
18,300
cubic meters per second. The estuary barrage impacts the Lower Nakdong
River
in the following fields: hydraulics, hydrology, sedimentation,
water-quality and stream ecology. Especially, because of the
construction of the barrage, the Lower Nakdong River has experienced
sedimentation problems requiring
dredging operation annually. The primary purpose of the dredging
operations
is to maintain the conveyance capacity of the channel in the event of a
large
flood combined with high water levels during high tides. The recent
historical
record shows dredging volumes of about 400,000 cubic meters of dredged
material
per year. The material dredged is primarily non-cohesive very fine sand.Un Ji has been working for the computer modeling to evaluate the sediment depositions on the upstream of the estuary barrage and determine the flushing time and the possible lowering water level at the barrage to remove the sediment deposition without dredging operation. The computer model is a one-dimensional unsteady flow and sediment transport model. |
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 CASC2D framework has been developed since 1991 by Dr. Julien  and his
students. CASC2D is the
numerical integrated surface hydrology and sedimentation program.
Additionally, it
can provide the runoff and sediment transport movies with time series. Currently, the Ph.D student Mark Velleux is upgrading CASC2D to include chemical transport. My focus area is the snowmelt processes in watershed. So, I am developing the snowmelt algorithms based on energy and mass balance equations, and add it into CASC2D framework. I will show hourly, daily, and monthly snowmelt processes in California Gulch. California Gulch in Leadville, CO has been hard mining area. Furthermore, California Gulch has the significant runoff during snow melting season. The goal of my research and thesis will to represent snowmelt procedure in California Gulch, and compare the simulated hydrographs with the measured hydrograph. Master thesis will be done at the end of July about the watershed snowmelt modeling in CASC2D. |
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 Hyeon-sik Kim is a
graduate student
of the hydraulic engineering program in Civil Engineering at Colorado
State University (CSU). He is currently working on here masters. He
came from South Korea and graduated from Chonnam National University,
Kwangju in 1992 with a BS in Civil Engineering. He has been working for
Korea Water Resources Corporation (KOWACO), which is establishing an
integrated water management system focused on water utilization and
flood control. In KOWACO, He worked on various flood control,
multi-purpose dam management, Investigation project of river basin, and
hydrology and hydraulics research projects. He is a Licensed
Professional Engineer in South Korea. He is interested in stream
rehabilitation and sediment transport The Imha
Multi-purpose Dam,
constructed at 18 km upper point from the start of Banbyeon stream, which is the first
tributary stream of
the Nakdong River, is a rockfill type dam that is 73 m in height, 1,361
㎢ in catchment area and has a storage capacity of 595 million ㎥ with a
flood control capacity of 80 million ㎥. The construction of this Dam
began in December 1984 and was completed 7 years and 6 months later in
May 1992. Imha dam has some problem, which is the inflow of turbid
water in reservoir, since it’s construction. Especially,
Nephelometric Turbidity Units (NTU) in Imha reservoir increased
dramatically by the typhoons “RUSA” in 2002 and
“MAEMI” in 2003. The maximum NTU is recorded by
1221 in
2003.Hyeon Sik will take the analysis of the Soil Loss quantity in Imha watershed using the Revised Universal Soil Loss Equation (RUSLE). He will look at the causes and alternatives of the turbid water in this area. |
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 Debris flow in Youngchon, South Korea  Predicted water storage capacity of soils calculated using relationship between soil porosity and slope, organic content, and elevation. |
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| Amanda
is currently working toward her masters degree in hydraulics.
She is originally from Tea, SD and received her undergraduate degree
from the University of Nebraska-Lincoln in May of 2006. After
years of living on the plains, her favorite part about living in
Colorado is seeing the mountains every day. Hydraulic Modeling Analysis  Channelization and dams placed along the middle Rio Grande River have caused changes in the morphology of the river. An understanding of the historic and predicted future conditions on the river is important for continued maintenance of the river by the Bureau of Reclamation. The Bureau of Reclamation office in Albuquerque, NM has commissioned a number of studies along the middle Rio Grande River to aid in understanding and maintenance of the river. The study reach is 19-miles long and stretches from Esocondida, NM to San Antonio, NM. Changes is channel width, cross-sectional area, mean bed elevation, water surface elevation, sinuosity, width/depth ratio, planform geometry, discharge, suspended sediment, etc. will be evaluated using programs such as ArcGIS, HEC-RAS, GeoTool, as well as other programs. Equilibrium conditions for slope and width will also be predicted using a variety of methods. An analysis of the floodplain and bedforms present in the reach was added to this report. The location and degree of inundation of the floodplain will be evaluated using aerial photography and HEC-RAS. An inventory of historic bedforms will be compiled and compared with predictions based on channel and flow characteristics. |
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| Middle
Rio Grande Database The Rio Grande Database was compiled as part of the work of PhD. Student, Claudia Leon in her study of the Middle Rio Grande in 1998. The database consists of measurements of discharge data, channel characteristics, and sediment data for the bed and water. The data for this project was obtained through the USGS and USBR and was used in numerous Hydraulic Modeling reports written for the USBR by CSU graduate students. The reach under analysis stretched from Cochiti Dam to the San Acacia Diversion Dam. This area is still under study for biological, hydrological, and geological changes. 
The
purpose of this project was to update this database with the most
recent possible data, using sources such as the U.S. Bureau of
Reclamation office, U. S. Geological Survey, and the USBR reports. The
data, analyses for each reach studied in the Middle Rio Grande, and the
reports themselves were organized into an interactive database DVD that
can
be accessed like a webpage. Through this, it is possible to view
analyses from each reach of the Rio Grande, each report, and the theses
and dissertations written by the students who have worked on this
project for the past several years. Hydraulic
Modeling AnalysisThe middle Rio Grande River is one of the most historically studied rivers in the US. Changes to the river due to the installation of several dams and channelization has led the US Bureau of Reclamation in Albuquerque, NM to commission hydraulic summaries of several reaches in the river. The reach studied in this analysis is 10-miles long, stretching from Cochiti Dam to Santo Domingo, NM. The morphology of this reach is being studied for changes in the cross-section, width, mean bed elevation, water surface elevation, sinuosity, width/depth ratio, planform geometry, discharge, suspended sediment load and concentration, etc. GIS, HEC-RAS, Geo-Tool, and other programs are being utilized in this study. Expected results are similar to those discovered by the other reaches downstream of the dam. This reach should experience magnified changes, however, since it is immediately downstream of the dam. The bed will have degraded, armored into a gravel-bed river; the sediment concentration and load will be much smaller now since the dam is releasing nearly clear water. The width has narrowed and the width/depth ratio has decreased. Since the dam upstream is controlling the discharge, peak flows have probably been drastically reduced to control flooding. This analysis will be finished by the end of the summer with the thesis defense in the fall of 2005. |
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Seema
Shah is graduate student in Civil Engineering at Colorado State
University. She is currently working on here masters in
hydraulics. She graduated from California Polytechnic State
University, San Luis Obispo in 2001 with a BS in Environmental
Engineering. Prior to attending CSU she spent 3 years working
as
a Design Engineer for RBF Consulting in Storm Water
Management.
She worked on various flood control, hydrology and hydraulics
projects. She is a Licensed Professional Engineer for the
State
of California. She is interested in river mechanics and
sediment
transport.
 The
Bureau of
Reclamation Automated
Modified Einstein Procedure (BORAMEP) is a computer program that
utilizes the Modified Einstein Procedure to estimate the total load and
sand load at a given cross-section. Forest Jay,
a master’s student at CSU estimated the total load and sand
load
within the low flow conveyance channel (Diverted from the Middle Rio
Grade) from San Acacia Diversion Dam to Elephant Butte
Reservoir.
He was able to determine reasonable total sediment concentration when
compared to measured results. However, a few errors were
encountered during his analysis. When there was not enough
overlap bins between the suspended load and bed load and
when the “z-value” became negative the program
would not
run. As a
result he estimated the sediment load by taking the average sediment
concentration and multiplying it by the flow rate. Seema will take the analysis of the BORAMEP to the next level. She will look at each input parameter within the program and determine an appropriate procedure to reduce the errors previously encountered. By varying the minimum % used in determining the z-value and changing the bin sizes she will be able to create a sensitivity analysis to determine the programs range. |
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  Young-ho
Shin will take
the analysis effects on
downstream
river channel
using aerial photographs which taken before and after dam construction.
The study focuses on the aspect of water, sediment and vegetation
interaction in the sand bed channel where the river flow is regulated
by upstream dams, in order words, hydro-geomorphologic changes in a
sand bed channel and thus vegetation expansion on the sandbars in the
channel by changes in the flow regime. The study area is the Nakdong
River in Korea. This river
is the longest river in South
Korea with its river length of 506km. The basin area of the river is
23,394km2, the second largest after the Han River (32,200km2). It
locates in the south east of the Korean Peninsula and generally the
river flows from north to south. The
riverbed is composed mostly of
sands except in the far upstream in the mountain area where it is composed
of gravel
and cobble. In the river basin, dams have been built since
1970’s
starting from the Andong
Dam in 1976. Since then,
more major
dams including the Imha Dam
(completed in 1991) and Hapcheon Dam (completed in 1988) have been
built for flood control, water supply and hydroelectric power
generation. Also, estuary barrage which is located at the end of
Nakdong River have been built to reduce salt-water intrusion and
prevent a large flood due to high tides. |
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Unmanaged
release of contaminants from upland source areas, their transport
across the land surface, and delivery to stream networks can have
adverse water quality and ecological impacts. Examples include
watershed transport of acid mine drainage (AMD) and metals from mining
areas, metals and organic chemical transport from military training
ranges, total maximum daily load (TMDL) sites. Chemical releases cause
or contribute to elevated chemical concentrations in water and have
toxic effects on aquatic organisms. The U.S. Environmental Protection
Agency (USEPA), the U.S. Army Corps of Engineers (USACE), and others
need quantitative tools to evaluate watershed contaminant transport and
to provide a basis for developing effective management plans that
address contaminant impacts at the watershed scale.  To
meet this need,
a numerical model to simulate the transport and fate of chemicals
across watersheds is under development. The model development effort
focuses on surface water hydrology with an emphasis on the transport
and fate of particle-associated chemicals. A computer code that
integrates the most critical hydrologic, sediment transport, and
chemical transport and fate processes into a single framework was
developed (Figure 1). This new code is called the Two-dimensional
Runoff, Erosion, and eXport (TREX) model and is based on Colorado State
University’s CASC2D watershed model with chemical transport
and
fate processes from the USEPA WASP and IPX series of stream water
quality models.The ability of TREX to simulate chemical transport and fate at the watershed scale is demonstrated by an application to the California Gulch watershed. Located near Leadville, Colorado, the California Gulch watershed is contaminated with wastes from mining activities (Figure 2). Mine wastes are widely distributed across the site. Chemicals of concern include cadmium, copper, and zinc. Click on Figure 3 to see a sample animation showing etals transport from California Gulch to the Arkansas River. |
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Graduate
students at CSU have been
examining the Middle Rio Grande for several years. Changes to
the
river, induced by the installation of several dams and channelization,
have led the US
Bureau of Reclamation in Albuquerque, NM to commission hydraulic
summary
reports of several reaches in the river, including the 10-mile long Rio
Puerco and 6.15-mile long San Felipe Reaches. Both reaches are also
included
in the habitat designation for two federally listed endangered species,
the
Rio Grande silvery minnow and the southwestern willow flycatcher. In
order
to facilitate restoration efforts for these species, it has been
necessary
to determine the historic, current and potential future geomorphic
configuration
of the channel.  The morphology of both reaches were previously studied for changes in the cross-section, width, mean bed elevation, water surface elevation, sinuosity, width/depth ratio, planform geometry, discharge, suspended sediment load and concentration, etc. Computer programs, such as ArcGIS, HEC-RAS, and Geo-Tool, were utilized in this study. The Rio Puerco Reach has shown a recent (1972-1992) trend toward degradation, thereby decreasing the width-depth ratio and sinuosity, while increasing the velocity and slope. The San Felipe Reach has also shown a recent (1972-1992) trend toward degradation. The purpose of this particular project is to update the hydraulic summary reports for the Rio Puerco and San Felipe Reaches in order to determine if the recent trendstoward degradation are still evident. This will be completed utilizing the aforementioned computer programs and new data sets from the US Bureau of Reclamation. The project will be completed by the end of fall of 2005. |
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I am a
part-time
graduate student in hydraulic engineering at Colorado State University.
Both Oregon State University and CSU felt obliged to offer me a
bachelors and masters degree in civil engineering, respectively. In
between school and work I managed to become a licensed professional
engineer in Oregon and a registered professional hydrologist through
the American Institute of Hydrology. In order to insure that my
graduate studies progress at a glacial pace, I currently work as the
forest hydrologist on the White River National Forest in Glenwood
Springs. My current research centers on using some clever site-calibration techniques to expand the; scope of bedload transport formulae for gravel bed rivers to higher gradient, cobble dominated systems. As stream gradient and bed material size increases, bedload transport; transitions from relatively frequent mobilization of the surface layer to more fine-grained material moving over a relatively immobile bed. Consequently, bedload transport models appropriate for gravel bed streams, such as Parker and Klingeman, Meyer-Peter and Mueller, Wilcock and Crowe, etc., largely over; predict measured bedload transport rates as streambed armoring increases in cobble bed streams. To account for this transition I am reevaluating the role and magnitude of a shear partition in these systems and looking at ways to incorporate surface armoring and variable reference shear as predictor variables in both surface-based and subsurface-based bedload transport equations. |
This
quasi-unsteady,
one-dimensional model computes bed aggradation and degradation
processes driven by time-varying, discretized water discharge. The
model provides the changes in bed slope of sequential channel reaches
of different widths in response to the discharge varied at each time
step. Other time varying parameters include temperature, kinematic
viscosity of flow, and fall velocity of the sediments.
Expansion
and contraction losses are also accounted for but local acceleration is
neglected. Aggradation and degradation computations are made
in a
separate module
of the program. The code allows for a limit the maximum bed
degradation in order to account for the existence of man-made or
geologic controls in the channel bed. The amount of sediment
aggraded or degraded at each section of the reach is calculated with
consideration for this maximum degradation limit.
