Transcript MnDOT*s Flood Vulnerability and Adaptation Assessment Pilot Project

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FHWA Climate Change Resilience Program
◦ Assessment Framework
◦ Transportation Vulnerability
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Flash Flood Vulnerability project
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Background
Objectives
Key project questions
System-wide vulnerability assessment
Facility-level risk analysis
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Program Goals:
 Advance transportation climate resilience activities
 Assist FHWA in building the Vulnerability Framework into
an Adaptation Framework
 http://www.fhwa.dot.gov/environment/climate_change
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Funded 5 pilot projects in 2010 to test an
assessment conceptual model
Funded 19 pilot projects, including Minnesota, in
2013 as part of an effort to test the Framework
A guide for transportation agencies
to assess vulnerability to climate
change and extreme weather events
3 key steps:
1. Define study assets and
climate variables
2. Assess vulnerability
3. Incorporate results into
decision making
*http://www.fhwa.dot.gov/environment/climate_change/adaptation/
resources_and_publications/vulnerability_assessment_framework/
“Climate change vulnerability in the transportation
context is a function of a transportation system’s
exposure to climate effects, sensitivity to climate
effects, and adaptive capacity.” (Vulnerability Framework)
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Exposure- whether the asset or system is located in an area
experiencing direct impacts of climate change
Sensitivity - how the asset or system fares when
exposed to an impact
Adaptive capacity - the systems’ ability to
adjust or cope with existing climate variability
or future climate impacts
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Minnesota GO Vision &
Statewide Multimodal
Transportation Plan identified
the risk of flash flooding as a
result of changing
precipitation patterns due to
climate change.
From 1958 to 2011, the
Midwest has seen 45%
increase in very heavy
precipitation (NOAA)
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Better understand the trunk highway network’s
risk from flash flooding
Identify cost-effect options to improve the
network’s resiliency
Support the development of Minnesota’s first
Transportation Asset Management Plan (TAMP)
Provide feedback to FHWA on the Draft
Framework
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General systems-level vulnerability assessment
of the trunk highway network in
District 1 and District 6
◦ Timeline: September 2013 – February/March 2014
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Focused facility-level adaptation assessment for
specific high-risk facilities identified in the
system-level assessment
 March 2014 – June/July 2014
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How is the climate projected to change in the
future?
What are acceptable methods for analyzing
potential risks caused by those changes?
What are risks identified for future conditions?
What adaptation measure can be put in place to
address risks?
How are decisions made on what is the most
appropriate course of action?
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Vulnerability = Structural strength of assets
(bridges, road segments, culverts) against
projected climate changes (precipitation)
Risk includes two components:
1. The likelihood an event (flash flooding) will
occur
2. The magnitude and
consequences of climate events
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High-level screen of trunk highway network
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Identify assets at risk from flash flooding
◦ Obtain information on asset condition and
features
◦ Gather information on climate projection changes
◦ Rank and prioritize assets based on resiliency and
projected climate changes (risk score)
 Risk scores will help determine where to prioritize facility
level adaptation assessments
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SimClim Version 2.5.9.10
A proprietary software
developed by Climsystems
Ltd., a private firm based in
New Zealand
Uses AR4 climate modeling done for the IPCC
Provides
◦ Downscaled maps of projected climate variables
◦ Future precipitation return periods (given a selected emissions
scenario)
Select weather stations in watersheds based
on available data in SimClim
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Present-day 100-year 24-hr storm precipitation depths for
each station
Year 2100 projected100-year 24-hr storm precipitation
depths for each station
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Assign weights to each watershed based
on the projected % change in the 100-year
24-hr storm
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Assets in watersheds where the percentage change
in precipitation is higher should be considered at
higher risk
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Obtain present-day 100-year 24-hr storm
precipitation depths for each station from SimClim
Presently 168.29
mm.
(6.63 in.) for
Rochester
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Obtain year 2100 projected 100-year 24-hr storm
precipitation depths for each station from SimClim
Projected 245.73
mm.
(9.67 in.) for
Rochester
(46% increase)
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Calculate a spatial average of
the % change for each
watershed
Use the spatial average of
the % change as a weight in
the risk score calculation
Assets in watersheds where
the percentage change in
precipitation is higher should
be considered at higher risk
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Assets will be mapped according to risk
scores for each District
◦ Maps will help identify which assets to include in
the facility-level assessment
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System-wide assessment will be an
example of method to screen for risks in
other parts of the state
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2 high-risk facilities (one per District)
◦ Determine whether (and which) adaptive actions are
economically justified for each at-risk asset
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Select 3 climate scenarios to test asset resilience
◦ Conduct hydrology/hydraulic analysis at facilities for each
climate scenario
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Assess for other potential risks (temperature, etc.)
Develop adaptation options (design alternatives)
Conduct analysis of cumulative benefit/cost values
from adaption options
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Projection out year: Based on remaining asset
design life
◦ Projections will be gathered for 20-year
increments
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Climate model: Same as system-wide
assessment
Specific climate variables
◦ Precipitation
 Duration TBD by hydrologic location
 Full range of return periods (2-500 years)
◦ Temperature (TBD if needed)
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Scenarios will be used to measure resiliency
of the assets
AR5 scenarios
◦ Three climate model scenarios
 High – 90th percentile of projections across all
emissions scenarios and models
 Medium – 50th percentile value
 Low – 10th percentile value
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Also include a scenario using 90% upper confidence
interval limit from NOAA Atlas 14
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Identify potential changes and make
recommendations to the FHWA framework
System-wide vulnerability assessment
◦ Maps will be used as examples of risk screening
◦ Methodology can be recreated in different parts of the
state
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Facility-level analysis:
◦ Mitigation or adaptation strategies and design details
will be listed as recommendations in the final report
◦ Cumulative benefit/cost values from adapting design
changes will be an example for future planning and
programming