Rationalizing the 1962-2006 Drop in Water Levels of Lakes Michigan and Huron
-
Upload
moin-syed -
Category
Environment
-
view
18 -
download
0
Transcript of Rationalizing the 1962-2006 Drop in Water Levels of Lakes Michigan and Huron
Rationalizing the 1962-2006 Drop in Water Levels of Lakes Michigan and HuronSyed M. A. Moin, IJC Ottawa Anthony J. Eberhardt, USACE, VA
3rd International Conference on Current & Future State of Water Resources and Environment
Chennai, IndiaJanuary 7, 2010
Paper OutlineStudy area and objectivesDefining the issuesStudy organizationStudy approach & peer review processStudy strategyScientific and technical projectsScience questions & key findings
2010/01/07 2EWRI Conference - Chennai, India
Study Area
Lake Superior Outflow & Lakes Michigan -Huron
Inflow
Lake Huron Outflow & St. Clair River Inflow
Harbor Beach, Michigan
Cleveland, Ohio
2010/01/07 3EWRI Conference - Chennai, India
4
Study Objectives To investigate St. Clair River flow characteristics and
determine how the natural regime of the river has been changed by human activities.
Assess relative importance of St. Clair River conveyance, hydroclimatic and other factors in the decline in levels since 1997.
To investigate whether the current Lake Superior outflow management procedures could be improved considering evolving upper Great Lakes interests and climate change.
To make recommendation to the IJC on changes and actions that may be necessary.
To 2
009
To 2
012
2010/01/07 EWRI Conference - Chennai, India
2.2 m
2.4 m
2.6 m
2.8 m
21 ft
Dr
edgi
ng
25 ft
Dr
edgi
ng
27 ft
Dr
edgi
ng
Drou
ght
1999
The Issues: Explaining the State of Lake Levels & Head Decline
2010/01/07 5EWRI Conference - Chennai, India
6
Independent Peer Review
Precise Metrics & Proper
Methodology
Qualified & Experienced Personnel
CoreScience
QuestionsSediment
FactorsHydraulic &GIA Factors
HydroclimaticFactors
Histor
ical
Data A
nalys
isSupplem
entary
Field Measurem
ents
Modelling
Methodology / Strategies
Sub-products Synthesis Final Report
Multiple Thematic ApproachIndependent Peer Review
IUGLS Study Organization - Management Framework
Lake SuperiorRegulationTask Team
InternationalJoint
Commission
Public /Stakeholders
IJC StudyLiaison
Independent ReviewGroup
Communications Group
IUGLSStudyBoard
StudyManagers
PublicInterest Advisory
Group
InformationManagementPhysical Data &
Visualization
Continued withTask Framework
St. Clair RiverTask Team
Continued fromManagement Framework
Lake SuperiorRegulationTask TeamPlan
Evaluation
Coastal ZoneEcosystem
Water Uses
CommercialNavigation
Hydro
Recreation Boating & Tourism
DataVerification &Reconciliation
Surveys &Monitoring
Hydraulic Modelling
Sediment Studies
Mitigation Issues(if required)
Hydroclimatic
St. Clair RiverTask Team
IUGLS Study Organization - Task Framework
Setting the Studies
2010/01/07 8EWRI Conference - Chennai, India
Sediment Science Questions:Has the "Morphology" of the St. Clair River been altered since the 1962 dredging?
a) Is the St. Clair River bed stable or eroding?b) If the bed of the St Clair river is eroding, what initiated it, and when?
9
1. Bathymetry changed between 1971 and 2007 (an enlarged channel).
2. Since 2000 there has been no net change in the bathymetry.
3. There is a limited bed mobility (bed forms) but no net change.
4. Shear stresses along entire river are insufficient to erode the bed.
5. Shipping, ice jams can increase shear stress.
HydraulicScience Questions:What is causing the declining head difference between Lake Michigan-Huron and Lake Erie?
a) Has the conveyance capacity of the St. Clair River changed since 1962?b) If the conveyance capacity has changed what were the causes?
10
1. Increase in conveyance capacity accounts for 11 cm decrease in Lake Huron level between 1971 and 2000 and is now stable.
2. Conveyance capacity increased by about 270 m3/s (less than 5% of the mean flow) for a brief period in the mid 1980s.
3. About 88% of the change in conveyance has occurred in the lower river. The mouth of the river is not a control section.
4. Conveyance probably changed in mid 1980s due to ice jam (1984).
Hydroclimatic
11
1. Hydroclimatic models suggest that increased conveyance capacity (8-9 cm/3.5 in) and climatic factors (9-27 cm/3.5 to 10.5 in) account for a drop of Lake Michigan-Huron between 1986-2005.
2. From 1962 to 1986, climate and conveyance were major factors.
3. Climate was by far the major factor for 1996 to 2005 period.
• Science Question:How has climate affected the change in lake level relationship between Lake Michigan-Huron and Lake Erie?
12Mul
tiple
Them
atic R
esul
tsType of Analysis
Water Level Change
Flow Change
1-D Basic HEC-RAS Modelling 10 cm (3.9 in)290 m3/s
(10,233 ft3/s)
1-D Inverse HEC-RAS Modelling -320 m3/s
(11,292 ft3/s)
1-D Conveyance analysis* 2.5 to 3.2% 140 - 290 m3/s(4940 to 9350 ft3/s)
RMA2 2-D Modelling 12 cm (4.7 in)290 m3/s
(10,233 ft3/s)TELEMAC 2-D Modelling 13 cm (5.1 in) -
HydroSed 2-D Sediment Modelling 9 cm (3.6 in) -
Lake-to-lake water level analysis8 to 10 cm
(3.1 to 3.9 in) -
Gauge-to-gauge water level analysisUp to 14 cm
(5.5 cm) -
Flow generation with HPG**-
170 m3/s (6000 ft3/s)
HPG analysis 12 cm (4.7 in)290 m3/s
(10,233 ft3/s)Stage-Fall-Discharge equation analysis 8 cm (3.1 in) -
Mid-lakes Routing 13 cm (5.1 in) -Coordinated Routing - Component 8 cm (3.1 in) -Coordinated Routing - Residual 7 cm (2. 8 in)
Deterministic Mid-lakes Routing 7 cm (2. 8 in) -
Hydraulic Modelling
Data and Flow Analysis
Hydroclimate Modelling
* Change expressed as percent change in conveyance since 1971** Value reported from dynamic simulation of flows; average change reported.
Explaining the Decline
2010/01/07 13EWRI Conference - Chennai, India
Principal RecommendationsCompensation Measures
Remedial measures not be undertaken in the St. Clair River at this time.
Addressing Effects of Long-Term Climate Change
The need for mitigative measures in the St. Clair River be examined as part of the comprehensive assessment of the future effects of climate change on water supplies in the upper Great Lakes basin in Report 2 of the Study, on Lake Superior regulation.
2010/01/07 14EWRI Conference - Chennai, India
“Legacy” RecommendationsStrengthening Data Collection
Conduct bathymetric surveys every five yearsSupport the operation of the Study’s four new stream flow gauging stationsMaintain the operation of the two eddy co-variance (evaporation) gauges
Accountability Structure
2010/01/07 15EWRI Conference - Chennai, India