calibration of unsteady hec-ras model for complex...
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Calibration of Unsteady HEC-RAS Model for
Complex Overflowing Channels – CVFED
Sacramento River Model near the Flood Relief
Structures
Flood Management Association 2014 Annual Conference
September 3, 2014
Presented by
Chakri Malakpet, PE
Mark Glidden, PE
Alan Turner, PE, CFM
CH2M HILL
Overview of the Presentation
DWR CVFED Program Objectives
Current Study Area Overview
Calibration Challenges
Methodology and Processes Used
Lessons learnt and tips for HEC-RAS Users
DWR Central Valley Floodplain Evaluation
and Delineation (CVFED) Program
Develop foundational datasets, models, and tools associated with
SPFC to support State’s flood management programs and projects
Improve quality and accuracy of flood hazard data to help local
communities comply with (recent) legislative mandates (SB 5, AB
156, SB 1278/AB 1965, etc.)
Develop new hydraulic models acceptable to the USACE and
FEMA and available for use for future studies.
Provide information to support future planning and project design
DWR Central Valley Floodplain Evaluation
and Delineation (CVFED) Program
CH2M HILL was tasked to develop an unsteady HEC-RAS
model for the Sacramento River System
Model extents are from Hamilton City to Fremont Weir
Consists of complex network of levees, weirs, inline structures,
flood relief structures and bypass channels
CH2M HILL Study Area
HEC-RAS and FLO-2D
Upper Sacramento River System
Mainstem
Colusa Drain
Knights Landing Ridge Cut
Sutter Bypass
Cherokee Canal
Butte Creek
Chico Areas Streams
Mud Creek
Sycamore Creek
HEC-RAS only
Deer Creek
Elder Creek
HEC-RAS System Model
Un-leveed main stem Sacramento River upstream of
RM 183.5 on Right Bank
RM 174 on Left Bank
Tributary channel inflows
Mud Creek
Big Chico Creek
Stony Creek
Butte Sink - Natural Bypass
Flood Relief Structures (FRS)
M&T
3B’s
Goose Lake
Meandering low-flow channels
3D Animation of the Terrain
Calibration Challenges
HEC-RAS Model was Calibrated to Observed Flow, Stage and High Watermark Data
Complex Natural 3D Hydraulic Functions represented as 1D System
Overflows from the River, through FRS enter into Butte Sink
Similar Water Surface in the River and Butte Sink create dynamic flow exchange between the channels
Complex 3D Natural Functions
M&T FRS
3B’s FRS
Calibration
Methodology
Calibrated to observed peak flow,
stage and high watermark data
Sacramento River at Hamilton City
Gage – DWR A02630
Sacramento River at Ord Ferry
Gage – DWR A02570
Sacramento River at Butte City
Gage – DWR A02500
Hamilton
City Gage
Ord Ferry Gage
Butte City Gage
Wide Cross Sections and
Storage Areas
Meandering channel
segments are modeled
using combination of
storage areas and cross
sections
Butte Sink is modeled as
a parallel channel with
wide cross sections
Storage
Area
Spatially varied Manning’s N
values
General guidance adopted
based on Land Use Type
0.035 Light Vegetation
0.04 Cultivated Crops
0.045 Light Brush and Grassy
0.055 Orchards
0.1 Wooded
Adjusted valued to 15% to 30%
to represent the complex
hydraulic functions
0 2000 4000 6000 800080
85
90
95
100
105
110
115
120
Station (ft)
Ele
vatio
n (
ft)
Legend
WS Max WS
Ground
Levee
Bank Sta
.045 .06 .04 .06
Lateral Weir
Coefficients
Weir coefficients for the
Lateral Structures
representing the FRS are
adjusted to minimize the
differences between
computed and observed
flow and stage values.
Weir Coefficient values
used range between 0.5
and 1.5
-1000 0 1000 2000 3000 4000 5000 6000 700080
90
100
110
120
130
140
Station (ft)
Ele
vatio
n (
ft)
Legend
Lat St ruct
Ground
Bank Sta
-2000 0 2000 4000 6000 800060
70
80
90
100
110
120
130
Station (ft)
Ele
vatio
n (
ft)
Legend
Lat St ruct
Ground
Bank Sta
M&T FRS
3B’s FRS
Levees & Ineffective
flow areas
Levees and ineffective flow
areas are used to manage
the flow movement in cross
sections at different
hydrologic conditions
Temporary and Permanent
ineffective flow areas are
used
0 1000 2000 3000 4000 5000 6000 700085
90
95
100
105
110
115
120
125
Station (ft)
Ele
vatio
n (
ft)
Legend
WS Max WS
Ground
Levee
Ineff
Bank Sta
.045 .04 .045
Peak WSE Profiles along Butte
Sink – Iterative Process
90
95
100
105
110
115
120
125
130
135
140
166 168 170 172 174 176 178 180 182 184 186 188 190 192
Wat
er S
urfa
ce E
leva
tion
(ft,
NA
VD
88)
Sacramento River Channel Distance in Miles
Butte Sink Initial Butte Sink Final SAC Initial SAC Final Observed Stage HWM
3B's Flood Relief Structure
Goose Lake Flood Relief Structure
Starting point of Left Bank Project Levees
M&T Flood Relief Structure
Dynamic Flow Exchange
Peak Q & WSE Profiles
80
90
100
110
120
130
140
150
160
201
200
200
199
198
196
195
194
193
192
190
189
188
186
185
184
183
182
180
179
178
177
175
174
172
171
169
168
167
166
165
164
162
161
Wat
er S
urfa
ce E
leva
tion
(ft, N
AVD8
8)
Calibration Band Initial Final Observed Stage
50,000
70,000
90,000
110,000
130,000
150,000
201
200
200
199
198
196
195
194
193
192
190
189
188
186
185
184
183
182
180
179
178
177
175
174
172
171
169
168
167
166
165
164
162
161
Flow
(cfs
)
Sacramento River Channel Distance in Miles
Calibration Band Initial Final Observed Flow
Ham
ilton
City
Gag
e
Ord
Fer
ry G
age
Butt
e Ci
ty G
age
Mud
Cre
ek In
flow
Big
Chic
o Cr
eek
Inflo
w
M&
T FR
S
Ston
y Cr
eek
Inflo
w
3B's
FRS
Goo
se L
ake
FRS
Peak Q – Calibration & Verification
13
5,0
00
11
0,0
00
11
6,0
00
13
4,9
83
10
9,4
44
11
7,5
64
-3,000
-2,000
-1,000
0
1,000
2,000
3,000
0
30,000
60,000
90,000
120,000
150,000
180,000
Sac R @ Hamilton City Sac R @ Ord Ferry Sac R @ Butte City
Dif
fere
nce
(cf
s)
Pea
k Fl
ow
(cf
s)
Observed Cablibration - 2006 Difference
15
50
00
12
00
00
13
32
61
15
5,0
00
12
1,8
35
13
7,2
44
-5,000
-3,750
-2,500
-1,250
0
1,250
2,500
3,750
5,000
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
200000
Sac R @ Hamilton City Sac R @ Ord Ferry Sac R @ Butte City
Dif
fere
nce
(cf
s)
Pea
k Fl
ow
(cf
s)
Observed Verification - 1997 Difference
Peak WSE – Calibration & Verification 1
48
.9
11
7.4
92
.4
14
9.1
11
7.1
92
.0
-1.00
-0.50
0.00
0.50
1.00
0
45
90
135
180
Sac R @ Hamilton City Sac R @ Ord Ferry Sac R @ Butte City
Dif
fere
nce
(ft
)
Pea
k W
SE (
ft, N
AV
D8
8)
Observed Cablibration - 2006 Difference
15
0.0
11
8.6
94
.3
15
0.2
11
8.3
93
.7
-1.00
-0.50
0.00
0.50
1.00
0
45
90
135
180
Sac R @ Hamilton City Sac R @ Ord Ferry Sac R @ Butte City
Dif
fere
nce
(ft
)
Pea
k W
SE (
ft, N
AV
D8
8)
Observed Verification - 1997 Difference
Hydrographs – Ord Ferry Gage
0
20,000
40,000
60,000
80,000
100,000
120,000
12/14/2005 12/19/2005 12/24/2005 12/29/2005 1/3/2006 1/8/2006 1/13/2006 1/18/2006 1/23/2006 1/28/2006
Flo
w (
CFS
)
Observed Initial Final
95
100
105
110
115
120
12/14/2005 12/19/2005 12/24/2005 12/29/2005 1/3/2006 1/8/2006 1/13/2006 1/18/2006 1/23/2006 1/28/2006
Ele
vati
on
(Fee
t, N
AV
D8
8)
Observed Initial Final
FLOW
STAGE
Lessons Learned & Tips
Comparison of Q & WSE profiles between parallel channels is
the key to understand the interaction
Roughness adjustment needs to be performed keeping in mind
the natural functions of the system
Levees and Ineffective flow areas help in calibration and
model stabilization
Use of storage areas in between the meandering sections is an
effective way to model the natural phenomena
Questions ?