Download Optimized Flood Control in the Columbia River Basin for a

Optimized Flood Control in the
Columbia River Basin
for a Global Warming Scenario
Se-Yeun Lee1,
Alan F. Hamlet 2,1
Carolyn J. Fitzgerald3
Stephen J. Burges1
Dennis P. Lettenmaier1, 2
1 Dept. of Civil and Env. Engineering, UW
2 CSES Climate Impacts Group, UW
3 U.S. Army Corps of Engineers, Seattle District
Motivation
Trends in April 1 Snowpack from 1950-1997
Red - Negative Trend
Blue – Positive Trend
Mote P.W.,Hamlet A.F., Clark M.P., Lettenmaier D.P., 2005, Declining mountain snowpack in western
North America, BAMS, 86 (1): 39-49
As the West warms,
spring flows rise
and summer flows
drop
Stewart IT, Cayan DR,
Dettinger MD, 2005:
Changes toward earlier
streamflow timing across
western North America, J.
Climate, 18 (8): 1136-1155
Red - Negative Trend
Blue – Positive Trend
Hydrologic Impacts of Global Warming
on Snowmelt Dominant Rivers
1200
20th Century
 Increased Winter Flows
 Earlier Melt
 Earlier Spring Peak Flow
Inflow (KAF)
 Reduced Spring Snowpack
Climate Change
800
400
 Decreased Summer Flow
0
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep
Month
8000
7000
6000
5000
4000
3000
2000
1000
0
Sep
20000
15000
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
Dec
Nov
10000
Oct
Jul
Full
25000
Storage
: Current Climate
Aug
Jun
Apr
May
Mar
Feb
Jan
Dec
Oct
30000
Nov
Reservoir Inflow
Flood Control vs. Refill
Flood Control vs. Refill
Streamflow timing shifts can reduce the reliability of reservoir refill
8000
+ 2.25 oC
6000
5000
4000
3000
30000
Full
2000
1000
25000
: Current Climate
Storage
Sep
Jul
Aug
Jun
Apr
May
Mar
Jan
Feb
Dec
Oct
0
Nov
20000
: + 2.25 oC No adaption
15000
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
Dec
Nov
10000
Oct
Reservoir Inflow
7000
Flood Control vs. Refill
Streamflow timing shifts can reduce the reliability of reservoir refill
8000
7000
+ 2.25 oC
5000
4000
30000
3000
Full
2000
1000
: Current Climate
Storage
Aug
25000
Sep
Jul
Jun
Apr
May
Mar
Jan
Feb
Dec
Oct
0
Nov
20000
: + 2.25 oC No adaption
15000
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
Dec
10000
Nov
: + 2.25 oC plus adaption
Oct
Reservoir Inflow
6000
Objective:
 Develop Systems Engineering
Procedures for Rebalancing Flood
Control and Reservoir Refill
Flood Control
Refill
Test Case: The Columbia River Basin
Multi-objective
Reservoir System






Flood Control
Hydropower
Instream Flow
Water Supply
Recreation
Navigation
Major U.S. Flood Control Checkpoints
Bonners Ferry
Columbia Falls
The Dalles
Methods
Optimization –Simulation Models
 Developing Optimized Flood Control Curves
 Testing and refining Proposed Rule Curves
HEC-PRM
(Hydrologic Engineering Center’s Prescriptive Model)
 Optimization model developed by the US
Army Corps of Engineers
 Penalty functions are used to constrain the
Columbia River basin system operation
 Flood control penalties
 Storage penalties
ColSim
(Columbia Simulation Model)






Flood control
Hydropower
Irrigation
Instream flow
Navigation
Recreation
Calibration Strategy
Select
Objective
Function
Parameters
Generate
Optimized
Flood
Rule
Curves
Adjust
AdjustParameters
Parameters
Evaluate
Flood and
Refill
Statistics
Using
Simulation
Calibration Results
Calibration Results (Refill)
Refill Probability (unit :%)
Dam
Arrow
20th Century Flow
Current FC
20th Century Flow
Optimized FC
8.1
18.6
Brownlee
36.0
36.0
Duncan
98.8
98.8
9.3
14.0
Grand Coulee
33.7
37.2
Hungry Horse
29.1
31.4
Libby
54.7
53.5
Mica
66.3
67.4
Dworshak
Calibration Results (Flood Control)
60
Bonners Ferry
50
Peak flow at Columbia Falls (kcfs)
Peak flow at Bonners Ferry (kcfs)
60
20th Cent_CurFC
20th Cent_HecFC
40
30
20
Columbia Falls
50
20th Cent_CurFC
20th Cent_HecFC
40
30
20
10
10
-2
-1
0
1
2
3
4
-2
5
-1
0
1
2
Y
Y
600
Red - Current FC
Blue - Optimized FC
Peak flow at The Dalles (kcfs)
The Dalles
500
20th Cent_CurFC
20th Cent_HecFC
400
300
200
100
-2
-1
0
1
2
Y
3
4
5
3
4
5
VIC Hydrologic Model
(Variable Infiltration Capacity Hydrologic Model)

Macroscale Hydrologic
Model developed by
University of Washington
Climate Change Scenario
 Remove historic monthly temperature trends
from the daily time step forcing data
 Increase the temperatures by 2 oC (annual
average) in a seasonal pattern derived from
several GCM simulations
 Observed precipitation
Monthly Simulated Reservoir Inflows
Dworshak
1200
20th Century
Inflow (KAF)
Climate Change Scenario
800
400
0
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Month
Libby
2,500
: Current Climate
: Climate Change Scenario
Inflow (KAF)
2,000
20th Century
Climate Change Scenario
1,500
1,000
500
0
Oct
Nov
Dec
Jan
Feb
Mar
Apr
Month
May
Jun
Jul
Aug
Sep
Creating
New Flood Control
Rule Curves
Current Flood Rule Curves
 Flood Control Rule Curves are selected by Apr-Jul Flow Volume
Dworshak Flood Control Curves
3700
Storage (KAF)
3300
2900
2500
2100
1700
1300
Nov
Dec
Jan
Feb
Mar
Month
Apr
May
Jun
New Flood Rule Curves
 Find Flow Volume Ranges for each category with an equal
number of events
Number
of samples
DW Apr-Jul
Flow Volume
FC 1
18
< 1.8 MAF
FC 2
17
< 2.6 MAF
FC 3
17
< 2.9 MAF
FC 4
17
< 3.2 MAF
FC 5
17
>=3.2 MAF
New Flood Rule Curves
 Find Flow Volume Ranges for each category with an equal
number of events
 Use 80th percentile values for each categories as a Flood
Rule Curve
DW Apr-Jul
Flow Volume
FC 1
18
< 1.8 MAF
FC 2
17
< 2.6 MAF
FC 3
17
< 2.9 MAF
FC 4
17
< 3.2 MAF
4,000
3,500
Storage (KAF)
Number
of samples
3,000
2,500
2,000
FC 4
1,500
1,000
Oct
FC 5
17
>=3.2 MAF
Nov Dec Jan Feb Mar
Apr May Jun
Jul
Months
: 17 ensemble traces
: 80th percentile of ensembles
Optimization Model Results
Current Climate vs Climate
Change Scenario
Dworshak storage
(Dworshak Apr-Jul flow volume >2.40 MAF)
a) 20th Century Climate
Mar
4,000
3,000
2,500
2,000
b) Climate Change Scenario
1,500
1,000
Oct Nov Dec Jan Feb
Mar Apr May Jun
Jul
4,000
Months
Feb
3,500
: Ensemble traces
: 80th percentile of ensembles
Storage (KAF)
Storage (KAF)
3,500
3,000
2,500
2,000
1,500
1,000
Oct Nov Dec Jan Feb Mar Apr May Jun
Months
Jul
Libby storage
(Libby Apr-Aug flow volume >5.5 MAF)
a) 20th Century Climate
Apr
6,000
Storage (KAF)
5,000
4,000
3,000
2,000
b) Climate Change Scenario
1,000
0
Oct Nov Dec Jan Feb Mar Apr May Jun
Mar
Jul
6,000
Months
: Ensemble traces
: 80th percentile of ensembles
Storage (KAF)
5,000
4,000
3,000
2,000
1,000
0
Oct
Nov Dec Jan Feb
Mar
Apr May Jun
Months
 The changes in flood control rule curves are different for different projects
Jul
Simulation Model Results:
Reservoir Storage Results
Refill Probability of Libby
(Libby Apr-Aug flow volume>5.5 MAF)
20th Century Flow CC Scenario Flow CC Scenario Flow
Current FC
Current FC
HEC-PRM FC
June
54
39
71
July
61
42
61
Full
Storage (KAF)
6000
5000
4000
3000
2000
1000
CC_Scen_CurFC
CC_Scen_HecFC
0
Oct Nov Dec Jan Feb Mar Apr May Jun Jul
Month
Refill Probability of Dworshak
(Dworshak Apr-Jul flow volume >2.40 MAF)
20th Century Flow CC Scenario Flow
Current FC
Current FC
CC Scenario Flow
HEC-PRM FC
May
0
0
25
June
49
19
44
July
14
0
0
Storage (KAF)
3500
3000
CC_Scen_CurFC
CC_Scen_HecFC
2500
2000
1500
Oct Nov Dec Jan Feb Mar Apr May Jun
Month
Jul
Changes in Reservoir Storage
Total System Wide July Storage (KAF)
CC_Scen _HecFC
55000
50000
45000
: The Dalles Apr-Aug < 68 MAF
: 68 <= The Dalles Apr-Aug <100 MAF
: The Dalles Apr-Aug >=100 MAF
40000
40000
45000
50000
55000
CC_Scen _CurFC
 Greatest Improvement occurs in Mid flow years (
)
Simulation Model Results:
Flood-Frequency Results
Flood-Frequency Curves for Bonners Ferry
Peak flow at Bonners Ferry (kcfs)
60
50
20th_Cent_CurFC
CC_Scen_CurFC
CC_Scen_HecFC
40
30
20
10
-2
-1
0
1
2
Y
3
4
5
Flood-Frequency Curves for Columbia Falls
Peak flow at Columbia Falls (kcfs)
50
40
20th_Cent_CurFC
CC_Scen_CurFC
CC_Scen_HecFC
30
20
10
0
-2
-1
0
1
2
Y
3
4
5
Flood-Frequency Curves for The Dalles
Peak flow at The Dalles (kcfs)
600
500
20th_Cent_CurFC
CC_Scen_CurFC
CC_Scen_HecFC
400
300
200
100
-2
-1
0
1
2
Y
3
4
5
Conclusions
 Optimization studies provide an objective
method for rebalancing flood control and
refill objectives in complex reservoir
systems in response to hydrologic changes.
 The changes in flood control rule curves are
different for different projects, corresponding
to different changes in flow volume and timing
associated with warming in each sub basin.
Conclusions
 Optimized flood control rule curves show
reduced flood evacuation and earlier refill timing;
up to one month earlier for a climate change
scenario, compared with 20th century climate.
 For the climate change scenario, optimized
flood rule curves increase reservoir refill as well
as the system storage in moderate and high flow
years, while providing comparable levels of local
and system-wide flood protection in comparison
to the current flood control rule curves.
Future Work
 Extension and refinement of our methods using
daily time step optimization and simulation
models is needed to evaluate the robustness of
these techniques in more detailed planning
studies.
Questions?