Engineering, 2011, 3, 461-469
doi:10.4236/eng.2011.35053 Published Online May 2011 (http://www.SciRP.org/journal/eng)
Copyright © 2011 SciRes. ENG
Channel Response Prediction for Abandoned Channel
Restoration and Applicability Analysis
IL Hong, Joongu Kang*, Hongkoo Yeo, Yonguk Ryu
Department of Water Resources Research, Korea Institute of Construction Technology, Ilsan, Korea
E-mail: hongil93@kict.re.kr, jgkang02@kict.re.kr, yeo917@kict.re.kr, yuryu@kict.re.kr
Received February 9, 2011; revised March 22, 20 1 1; accepted March 31, 2011
Abstract
As channel evaluation for abandoned channel restoration design, this study sought to exam channel changes
from the past to the present and predict subsequently occurring river responses. For the methodology, chan-
nel geomorphology changes were evaluated through image analyses of annual aerial photographs to com-
plement the limited river data. Channel responses were predicted using an analytical stable channel model,
the SAM (Stable Channel Analytical Model) program, based on a stability theory as well as empirical equa-
tions for equilibrium channel. The results of the geomorphological channel changes showed that channels
became narrower and bed levels became lower, whereas vegetated bars expanded. The channel response pre-
diction results, narrower channels with deeper depths and mild slopes, were expected compared with the
current condition. The channel response, obtained by the field measurement data, image information, and
stability theory, are in relatively good agreements showing the reliability of the application suggested in this
study. Consequently, the comprehensive channel evaluation approach is expected to be applicable to aban-
doned channel restoration designs from the aspects of channel geomorphology and hydraulics.
Keywords: Abandoned Channel Restoration, Channel Evaluation, Aerial Photograph, Image Analysis
Method, Stable Channel Analytical Model, Regime Theory
1. Introduction
In the 1980s and 1990s, artificial river maintenance
through channel straightening has resulted in many
abandoned channels due to limiting natural rivers’ me-
andering. Such a geomorphological change has given
rise to many problems on river flows, drifting sands and
life forms. Abandoned channel restoration seeks to en-
sure stable flows and maintain ecological diversity by
securing flood plains that disappeared through channel
straightening. With the recent emphasis on the value of
river environments and the importance of flood plains
including abandoned channels, measures for restoring the
abandoned channels by integrating them into the river
basin are sought. Since a river changes incessantly,
however, the shape and physical features of a river are
likely to vary depending on new environmental condi-
tions when artificial disturbance occurs. Thus, for aban-
doned channel restoration, various reviews with regard to
the hydrologic and hydraulic process, river shape process,
chemical and biological features, and habitat evaluation
are required. Especially for the channel design of river
restoration, channel evaluation and channel response
prediction as to whether the current channel stays stable
or continuously changes are of importance due to the
river dynamics. Channel evaluation is very important in
selecting basic design factors such as channel shape, size,
slope, and discharge distribution. Although geomorpho-
logic, hydraulic, and hydrologic information of past and
current rivers is required for channel evaluation, obtain-
ing long-term past data of Korea’s rivers is very difficult.
Even though necessary data could exist, when river sites
for actual evaluation were segmented, collecting the data
would be almost impossible. However, Korea’s aerial
phonograph data have been accumulated since the latter
half part of the 1960s when the river maintenance pro-
jects and farmland arrangement projects did not start yet.
Therefore, the aerial photograph data can be very useful
for the evaluation of historical channel changes. More-
over, the GIS analysis technology enables the use of im-
age data to be relatively accurate and effective.
As a study applyin g an image analysis method, Kathe-
rine and Alan [1] evaluated channel shape changes for
many years including sandbar change and sinuosity
I. HONG ET AL
462
through analyses of longitudinal and cross sections. San-
dra [2] analyzed the relationship of channel shape
changes with flood frequency, flood size, rainfall, and
discharge data. Veerle et al. [3] analyzed the short-term
influence of artificial change on river changes based on
bed materials and land use. Duncan et al. presented a
direction for river management by assessing discharge
balance according to channel shape changes [4]. Al-
though there are many cases of applying image informa-
tion to the river analyses, the image method has been
rarely used for the purpose of channel design.
Methods of designing stable channels and equilibrium
channel features have been proposed by many research-
ers based on analytical or empirical equilibrium channel
theories. Copeland’s method is used most commonly for
stable channel evaluation and design in alluvial rivers
and is one of the analytical methods selected for the
SAM (Stable Channel Analytical Model) program de-
veloped by the US Army Corps of Engineers [5,6]. For
an empirical approach, various equilibrium theory
methods based on the downstream hydraulic geometry
have been introduced. Julien and Wargadalam [7], Sim-
mons and Albertson [8], Lacey (Wargadalam, re-cited)
[9], and Klaassen and Vermeer [10] suggested empirical
downstream hydraulic geometry equations. The river
hydraulic geometry can not only examine the geometric
characteristics of natural rivers but also be used for a
model of stable channel or artificial channel designs
from the river hydraulic aspect. Nowadays, it is also em-
ployed for a channel design of river restoration projects.
This study carried out channel evaluation on the res-
toration site of Cheongmi Stream’s abandoned channel
and examined the applicability of the channel evaluation
method. The applicability of the method was assessed by
comparing channel evaluation through an image analysis
method and an existing equilibrium method with the
measured data. For the channel evaluation through the
image analysis method, channel planform changes were
analyzed from 1969 to 2006 on the restoration site o f the
abandoned channel using the GIS analysis technique. For
the channel evaluation through the equilibrium theory
equations, equilibrium channel width and slope were
estimated using the analytical methods and the previ-
ously suggested empirical equations.
2. Study Area
Cheongmi Stream, the target river of this study, is the
primary tributary of South Han River; it has a length of
60.5 km and a basin area of 615.4 km2. Cheongmi
Stream is a typical alluvial stream and the artificial river
maintenance reaching a river’s repair rate of more than
97% has been carried out. In the process of channel
straightening of Cheongmi Stream, 20 abandoned chan-
nels were generated and mostly used as farmlands at
present. Among the abandoned channels, the planned
channel for the abandoned channel restoration, presented
in Figure 1, is from Section 15 + 800 to Section 16 +
800 and the restoration area is 154,000 m2. The site in-
cluding the restoration channel targeted for this study
measures about 4 km as shown in Figure 1.
In Korea, the development of river basins and the
dense land occupation cause limitations on channel res-
toration. In particular, the abandoned channel restoration
of Cheongmi Stream with the 1-way type has consider-
able difficulty in being conducted since the current
Figure 1. Study area and abandoned c hanne l r e stor ation site.
Copyright © 2011 SciRes. ENG
I. HONG ET AL
Copyright © 2011 SciRes. ENG
463
straightened channel is in stable state. Note that the
1-way type is the method which restores the current
channel into a naturally meandering condition. Hence,
the abandoned channel restoration project of Cheongmi
Stream has adopted the 2-way type that restores the
abandoned channel while maintaining the current chan-
nel. Thus, the channel design focuses on predicting the
hydraulic changes that may occur in the process that the
current one channel becomes two channels and applying
to the restoration.
3. Channel Evaluation Using an Image
Analysis Method
For the spatial analysis of the channel using images, aerial
photographs of 1969, 1974, 1981, 1992, 2000 and 2006
along with the 1918 geomorphology map were used.
Matching the image data to the coordinate system in the
GIS-based digital environment makes it possible to use
all the image information of the area of interest. In par-
ticular, the aerial photographs used in this study were
taken in April in the respective year, which possibly im-
plies relatively similar climate conditions.
This study examines the area where the river mainte-
nance mainly consisting of embankments and weir instal-
lations was carried out in 1983 and 1994. In general,
geomorphology in the alluvial channel continuously
changes by flood events and channel features such as a
channel slope and a material kind and consequently the
channel finally reaches equilibrium. However, planar
fixations due to river maintenances such as channel
straightening, channel width expansion and river struc-
tures cause the equilibrium channel to change. Figure 2
shows the chann el changes on the restoration site th rough
the yearly aerial photographs. In the figure, the weirs, a
river structure, were found to be installed at 2 upstream
places of the restoration site from the 2000 aerial photo-
graph. The 1992 aerial photograph also shows the em-
bankment installation in 1983. The river maintenances
carried out in the respective year are likely to result in the
rapid bar changes as well as flow changes shown in the
figure.
Figure 3 presents the yearly channel change trends ob-
tained from image analyses of the aerial photographs in
Figure 2 in term s of sand bar, vegetate d bar, vegetate d area,
farmland, water area, and parking zone. The channel state
of 1969, which was relatively close to the natural river,
shows a large difference from that of 2006 which was be-
ing stabilized after the completion of the river mainte-
nances. In case of the restoration sections of the abandoned
channel, alternate bars are located on both sides and the
growing vegetation is observed in some areas.
To identify such changes quantitatively, the respective
area and ratio of micro-landform state were calculated in
the channels from the digitized images (Table 1). From
the calculations of the channel characteristics, it is shown
that there was no significant change in the total channel
area between 1969 and 2006 while the vegetated bars,
sand bars, and water area vary. The vegetated bars in-
creased by about 33.4% (426,404 m2), whereas 12.8%
(160,350 m2) of the sand bars and 25.6% (322,145 m2) of
the water area decreased. In particular, the planform
change in water area may indicate that the channel was a
low-water channel including the thalweg along which the
flow lasts.
Table 2 presents the yearly width change of the
low-water channels, obtained by image-analyzing the
aerial photographs in Figure 2, at some main cross sec-
tions including the restoration sites of the abandoned
channels. The low-water channel width of each cross sec-
Figure 2. Aerial photographs of the study area from 1969, 1974, 1981, 1992, 2000, and 2006.
I. HONG ET AL
464
Figure 3. Example of a figure caption.
Table 1. Summary of 1969 and 2006 Micro-Landform characteristics in the study channel.
Classification Vegetated Bar (m2)Farmland (m2) Sand Bar (m2) Water Area (m2) Parking Zone (m2) Total C ha nne l Ar ea (m2)
1969 251,321
(19.9%) 36,588
(2.9%) 361,329
(28.5%) 616,854
(48.7%) - 1,266,093
(100%)
1974 353,568
(28.2%) 63,019
(5.1%) 222,133
(17.7%) 614,459
(49.0%) - 1,253,179
(100%)
1981 143,280
(11.4%) 130,391
(10.3%) 470,901
(37.4%) 515,119
(40.9%) - 1,259,691
(100%)
1992 752,569
(58.4%) - 298,071
(23.2%) 237,195
(18.4%) - 1,287,836
(100%)
2000 618,707
(47.3%) 26,210
(2.0%) 255,834
(19.5%) 408,285
(31.2%) - 1,309,036
(100%)
2006 677,725
(53.3%) 50,632
(4.0%) 200,979
(15.8%) 294,709
(23.1%) 47 795
(3.8%) 1,271,840
(100%)
tion appears to decrease gradually compared to the past.
The characteristics of channel planform changes pre-
sented in Figure 3. Table 1 and Table 2 show the chan-
nel became gradually narrower and the total bars in-
creased. As for the bar changes in detail, the sand bars
decreased while the vegetated bars increased. The ten-
dency of bar change shows the process of vegetation
gradually taking root with the fixation of the sand bars.
Consequently, the artificial river maintenances show that
natural change gradually decreases and only thalweg of
the low-water channel changes.
4. Prediction of Stable Channel Using
Equilibrium Methods
For the channel response prediction, this study employed
the previously suggested methods based on both analyti-
cal and empirical equilibrium bed theories. This study
evaluated the current channel’s stability by using Cope-
land’s method [5], one of the mostly used analytical
methods, as a basic module for the planned site of
Cheongmi Stream’s abandoned channel restoration.
Copeland’s method, one of the analytical methods used
for SAM of the US Army Corps of Engineers, is most
widely used for evaluation and design of stable channels
in alluvial rivers [6]. This method is similar to that of
Abou-Seida and Saleh [11]. Among 3 unknown variables
(channel width, slop e, and dep th of a stab le chann el), an y
two ones are calculated first. For the third unknown one,
the most suitable solution for design conditions and
geomorphological conditions is selected from several
solutions by a designer.
Copyright © 2011 SciRes. ENG
I. HONG ET AL 465
For the empirical method, the equations of Julien and
Wargadalam [7], Simmons and Albertson [8], Lacey
(Wargadalam, re-cited) [9], and Klaassen and Vermeer
[10] were used and compared. The equations of Julien
and Wargadalam, Simmons and Albertson, Lacey, and
Klaassen and Vermeer are typical empirical equilibrium
bed equations related to downstream hydraulic geometry.
4.1. Stable Channel Prediction Using Analytical
Methods
The stable channel slope in the restoration site of
Cheongmi Stream was calculated using SAM to which
Copeland’s method is applied. The input data for the
stable channel design used for SAM include the follow-
ing: bankfull discharge, Qb = 488 m3/s; specific gravity,
G = 2.65; valley slope, Sv = 0.00088; bank side slope,
2.3; bank roughness, 0.03; bed material gradation, d84 =
2.18 mm, d50 = 1.1 mm, d16 = 0.63 mm.
For the restoration site of Cheongmi Stream, the cal-
culated bottom widths using SAM and the corresponding
converted top widths are presented in Table 3. The cal-
culation for Cheongmi Stream gives 21 solutions of the
stable channel bottom widths ranging from 7.92 m to
160.02 m, the water depths for the bankfull discharge
ranging from 2.09 m to 7.61 m, and the energy slopes
ranging from 0.000912 to 0.000762. The relationships of
the slope with the width and the depth are presented in
Figure 4. The conditions for the widths, depths and
slopes plotted in Figure 4 mean a theoretically stable
state. The figure indicates that a river with a condition
falling under the region outside the relation curves could
get unstable. The unstable state is expected to be caused
by either erosion for the conditions over the relation
curves or sedimentation fo r the co nditions und er the rela-
tion curve. Figure 4 shows the calculated 21 solutions
for the stable channel includin g 1 solu tion with minimum
stream power.
Table 4 presents the surface curve data of Cheongmi
Stream in the current condition calculated using
HEC-RAS based on the geomorphological data meas-
ured in 2008. Note that the region from Section 15 + 8 to
Table 2. Changes in the low flow channel width along
Cheongmi Stream.
Cross section number
Year 15 + 523 16 + 40016 + 507 17 + 517
1969 99.8 108.6 132.8 87.5
1992 46.4 28.8 31.3 35.0
2000 39.4 18.0 53.2 66.3
2006 36.3 13.2 42.3 58.2
Table 3. Stable channel dimensions calculated using the
SAM program.
Bottom
Width
(m)
Depth
(m)
Top
Width
(m)
Energy
Slope
Hyd
Raidus
(m)
Velocity
(m/s) Froude
Number Bed
Regime
7.927.61 42.93 0.000 912 4.21 2.53 0.29Lower
16.156.90 47.89 0.000 688 4.35 2.21 0.27Lower
24.086.20 52.60 0.000 617 4.30 2.05 0.26Lower
32.005.58 57.67 0.000 589 4.16 1.95 0.26Lower
39.935.05 63.16 0.000 579 3.98 1.87 0.27Lower
43.704.8365.92 0.000 580 3.90 1.84 0.27 Lower
48.164.59 69.27 0.000 580 3.77 1.81 0.27Lower
56.084.22 75.49 0.000 587 3.59 1.76 0.27Lower
64.013.90 81.95 0.000 598 3.40 1.71 0.28Lower
71.933.63 88.63 0.000 609 3.23 1.67 0.28Lower
80.163.39 95.75 0.000 623 3.06 1.64 0.28Lower
88.093.18 102.72 0.000 637 2.91 1.61 0.29Lower
96.013.00 109.81 0.000 651 2.78 1.58 0.29Lower
103.942.85 117.050.000 665 2.66 1.55 0.29Lower
112.172.70 124.590.000 680 2.54 1.53 0.30Lower
120.092.57 131.910.000 694 2.43 1.5 0.30Lower
128.022.46 139.340.000 709 2.34 1.48 0.30Lower
135.942.36 146.800.000 723 2.25 1.46 0.30 Lower
144.172.26 154.570.000 737 2.17 1.45 0.31Lower
152.102.17 162.080.000 751 2.09 1.43 0.31Lower
160.022.09 169.630.000 762 2.02 1.41 0.31Lower
Section 16 + 8 is the planned area for the abandoned
channel restoration. The channel top widths by
HEC-RAS is calculated from 158 m to 236 m when a
bankfull discharge occurs, which are overestimated
compared with the stable channel top widths obtained by
the Copeland method. Moreover, in case the abandoned
channel restoration is carried out, the channel top widths
are expected to have a larger value rather than the stable
channel width since newly restored channel widths will
be added to the existing channel widths for the total
width estimation. Although the depths of the stable
channel obtained by SAM range from 2.09 m to 7.61 m,
the depths of the channel in current state by HEC-RAS
are estimated from 1.52 m to 2.09 m. The current chan-
nel slopes are slightly larger than those of the stable
channel and the differences are negligible. From the
comparisons, the stable channel estimated by SAM is
expected to have narrower width, deeper depth and
milder slope compared with the current channel condi-
tion and the HEC-RAS estimation. In particular, the re-
sult that the current channel width is wider than that of
the stable channel favorably accounts for why bars de-
velop in the current channel.
Copyright © 2011 SciRes. ENG
I. HONG ET AL
Copyright © 2011 SciRes. ENG
466
4.2. Channel Evaluation Using Empirical 12.2
1ln
s
h
md

(5)
Equilibrium Bed Equations
This study predicted the stable channel width, i.e. equi-
librium channel width, of the abandoned channel restora-
tion site of Cheongmi Stream using the equilibrium
equations, which are suggested by Julien and War-
gadalam, Simmons and Albertson, Lacey and Klaassen
and Vermeer.
where h (m) is the average flow depth, W (m) is the av-
erage width, V (m/s) is the average one-dimensional ve-
locity, Q (cfs) is the discharge, S is the channel sl ope, τ*
is the Shields parameter, ds (m) is the sediment size, and
m is the parameter determined from roughly estimated
flow depth.
Julien and Wargadalam used the concepts of resistance,
sediment transport, continuity, and secondary flow to
develop analytical hydraulic geometry equations as fol-
lows:
Simons and Albertson [8] used five sets of data from
canals in India and America to develop equations and
used the relationship graph of a wetted perimeter with a
discharge and a channel width to determine equilibrium
channel width.
 
2566 56156
0.2 mm mm
s
hQ dS

(1) 0.512
2.51PQ (6)

24 5645612 56
1.33 mmmm mm
s
WQd S

(2) where P (ft) is the wetted perimeter.
 
12 5625622 56
3.76 mmmm mm
s
VQd S
 
(3) Lacey (from Wargadalam) [9] developed a power re-
lationship for determining wetted perimeter based on
discharge.
 
2565564656
*0.121 mmm
s
Qd S
 
m
(4)
Table 4. Hydraulic characteri stics of the bankfull discharge condition for Cheongmi Stream.
Q (m3/s) River station Depth (m) Energy Slope Velocity (m/s) Top Width (m) Froude Number
16 + 800 1.52 0.000 980 1.38 232.98 0.36
16 + 600 1.65 0.001 258 1.64 179.59 0.41
16 + 507 2.09 0.000 669 1.40 166.97 0.31
16 + 400 2.08 0.000 747 1.48 158.60 0.33
16 + 200 1.79 0.000 898 1.46 186.31 0.35
16 + 000 1.81 0.000 850 1.43 188.78 0.34
488
15 + 800 1.57 0.000 873 1.32 236.08 0.34
Figure 4. Stable channel slope, depth and slope fr om SAM.
I. HONG ET AL 467
0.5
2.667PQ (7)
For wide and shallow channels, the wetted perimeter is
approximately equal to the width.
Klaassen and Vermeer [10] used data from Jamuna
River in Bangladesh to develop a width-discharge rela-
tionship for braided rivers.
0.53
16.1WQ (8)
The input data for the calculation of equilibrium
channel width using the empirical equilibrium equations
are: the bankfull discharge, Qb = 488 m3/s; the slope be-
tween Section 15 + 8 and Section 16 + 8, S = 0.00073;
the hydraulic depth of Section 16 + 4, 2.08 m; the bed
material size, d50 = 1.1 mm.
The equilibrium channel widths of the restoration site
of Cheongmi Stream obtained using the downstream
hydraulic geometric equation s and equilibriu m bed equa-
tions are compared with the current width for the bank-
full discharge estimated by HEC-RAS in Figure 5. Three
equations except the equation of Klaassen and Vermeer
[10] predict the equilibrium channel width to be between
100 m and 145 m, which are smaller than the HEC-RAS
channel width, 158.6 m. Note that the equation of Klaas-
sen and Vermeer over-predicting the channel width as
428.2 m has regional limitations considering a specific
region and considers only a braided channel. Although
Section 16 + 4 is the narrowest cross section within the
restoration site, the channel width by HEC-RAS is larger
than the stable channel width pred icted by the three eq ui-
librium equations.
5. Comparison and Discussion
The stable channel predictions for the abandoned res-
toration site of Cheongmi Stream carried out by both the
analytical and the empirical approaches of the equilib-
Figure 5. Equilibrium width using downstream hydraulic
geometry equations in Cheongmi Stream.
rium method are compared with the channel conditions
by HEC-RAS in Table 5. Among the methods for the
empirical estimation, Klaassen and Vermeer [10] is ex-
cluded because of its limitations in application and over-
estimation of the top width. Both the channel slope with
the min i mu m st re am p o we r est i mate d fr o m SA M an d th e
equilibrium slope from Julien and Wargadalam [7] are
larger than the current slope, which means the current
slope is in stable state. Since the change of Cheongmi
Stream into a natural meandering channel for a milder
slope is limited due to its current stable condition of
slope, it is expected that a weir and a drop structure
would supp lement the adju stment o f slope for abando ned
channel restoration designs. Moreover, Cheongmi
Stream’s current conditions calculated from HEC-RAS,
the wider width and shallower depth compared to the
predictions from both SAM and empirical equilibrium
equations, imply that a narrower channel can be more
effective in terms of hydraulics and geomorphologically
more stable.
The applicability of the comprehensive and comple-
mentary assessment using the analytical and empirical
equilibrium estimations of a stable channel to an aban-
doned channel restoration design was examined through
comparisons with the survey data measured in 1983,
1994, and 2004 and the image analysis of the aerial pho-
tographs. From the thalweg profiles shown in Figure 6,
the bed slope change from 1983 to 2004 was not signifi-
cant; the bed level was lowered gradually, however. The
average deepest bed level (El.) was 55.6 m in 1983, 54.6
m in 1994, and 54.0 m in 2004. Cross section shapes of
Sections 15 + 523, 16 + 507, 17 + 517, and 18 + 515
from 1983 to 2004 are compared in Figure 7. The aver-
age channel width of the four cross sections gets narrow
by about 30 m from 309.7 m in 1983 to 279.8 m in 2004.
From the comparisons of the bed level and the channel
width, the channel tends to keep the mild slope and get
deeper and wider, which is likely to be a change pattern
to a stable chann el. In addition, the wider current ch ann el
Table 5. Results of SAM, equilibrium methods, and
HEC-RAS for Section 16 + 400.
Bankfull
Discharge
(m3/s) Methods Slope
Width
(m) Depth
(m)
SAM 0.000 580 65.924.83
Julien and
Wargadalam 0.000 400 143.9-
Simons and
Albertson - 112.9-
Lacey (from
Wargadalam ) - 106.7-
488
HEC-RAS
(Present Condition) 0.000 747 158.62.08
Copyright © 2011 SciRes. ENG
I. HONG ET AL
468
width rather than the predicted stable channel width ex-
plains why the bars around the target channel have de-
veloped. The surveyed data as well as the information
about the area of the bars and waters from the aerial im-
age analysis show the pattern that the channel gets nar-
row and vegetation takes root on the subsequently de-
veloping bars. The historical channel change observed
from the measured data including the survey and aerial
photographs supports the channel response prediction by
the equilibrium methods.
6. Conclusions
This study suggested an assessment method for channel
response prediction using an aerial image analysis method
and the analytical and empirical equilibrium equations
Figure 6. Historical thalweg profiles of the study reach.
Figure 7. Cross section changes between 1983 and 2004 for the study reach.
Copyright © 2011 SciRes. ENG
I. HONG ET AL
Copyright © 2011 SciRes. ENG
469
for a stable channel condition. This approach in this
study can be a complementary way to estimate a channel
condition and subsequently suggest a plan for channel
designs or restoration projects since there has been a
need of an alternative channel estimation method due to
the lack of past measurement data in Korea. The current
channel’s state could be identified using the image analy-
sis method that shows macro phenomena on changes in
channel geomorphology such as channel width and bar
area. Although the image analysis results have a limita-
tion, i.e., providing only 2D information, the image
analysis method can be a very important method in
channel evaluation in a situation wherein sufficient data
have not been accumulated. For a stable channel state,
the analytical stable channel analysis and empirical equi-
librium bed equations provided quantitative values to
design the stable and equilibrium channel. Based on
findings of change pattern and values of stable channel
features, the method is expected to suggest a channel
plan from the channel’s geomorphological and hydraulic
aspects.
In this study, the channel response estimation method
was examined by applying it to the abandoned channel
restoration site of Cheongmi Stream. From the compari-
sons in the channel features between the existing meas-
ured data such as the survey data and aerial images and
the predictions of the study reach, the change pattern
predicted by the suggested method was found to be rela-
tively consistent with the measurements; thus confirming
the reliability of the applicability. The channel of the
restoration site is found to get narrower and deeper,
which is a progress into a stable channel. Based on the
findings from the comprehensive method, this study
proposes designing the abandoned channel to be restored
as a narrower one and supplying minimum discharge
favorable to the ecosystem since the abandoned channel
restoration in the target site plans to use a 2-way type. In
addition, since the current channel slope is higher than
the equilibrium channel slope, this study also suggested
installing slope-adju sting structures such as a drop struc-
ture to reach the equilibrium bed.
7. Acknowledgements
This study was partially supported by the 2006 Core
Construction Technology Development Project (06K SH S-
B01) through ECORIVER21 Research Center in KIC-
TEP of MLTM KOREA.
8. References
[1] F. L. Katherine and W. Alan, “River Channel Planform
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