Arizona Department of Transportation Extreme Weather Vulnerability Assessment

February 6, 2015

Presentation to PAG Environmental Planning Advisory

Council

Kris Gade, PhD

ADOT Environmental Planning Group

ADOT Extreme Weather Pilot Study

• Arizona and FHWA initiatives

• Pilot study focus on biotic communities

• Summary of results

• How ADOT will use the results

Extreme Weather Studies in AZ

2012: ADOT’s Preliminary

Study

FHWA Framework

December 2012 http://www.fhwa.dot.gov/environment/climate_

change/adaptation/resources_and_publications/vulnerability_assessment_framework/

19 FHWA Pilots for 2013-2014

Project Approach • Study corridor crosses several biomes

– Different transportation vulnerabilities

• Stressors

– Precipitation

– Temperatures

• Secondary impacts

– Wildfires

– Dust storms

– Runoff volumes (storms and post-fire)

– Heat sensitivity of infrastructure (pavement, etc)

Landscape Context • Biotic communities can

affect extreme weather risks to transportation

• Four groupings:

– Desert

– Grassland

– Chaparral

– Forest

Heat/cold sensitivity Heat/cold sensitivity Flooding/runoff Wildfire Dust storms Rockfall

Climate Stressors & Impacts

Temperature

Precipitation

Extreme Temperature Days above 100°F

Extreme Temperature Average Daily Maximum

Average Daily Maximum (F)

Past 2040 2080

1950-1999 2025-2055 2065-2095

Desert 84 88 92

Grassland 76 80 84

Chaparral 74 78 82

Forest 69 73 76

Extreme Precipitation Magnitude of 100-Year (1%) Rainfall

Potential Effects A Note on Symbology

• Negative effects: Likely to exacerbate risks

• Neutral, not relevant

• Uncertain effects

• Positive effects: Likely to reduce risks

All else being equal, projected changes in stressor frequency and/or severity are estimated to have:

Extreme Heat

• Pavement deformation, thermal expansion

• Construction schedules and seasons

• Worker safety

• Stranded motorists

Example Climate Indicators • Days exceeding 100°F • Average Daily Maximum Temperature

Potential Effects Increase in extremely hot days/maximum temperatures

Flagstaff

Phoenix

Tucson

Extreme Precipitation • Flooding/ Inundation

» Washouts

» Bridge scour

» Culvert damage

» Debris clogs drainage infrastructure (wildfires)

• Mudslides Example Climate Indicators • Magnitude of 100-year rainfall (24 hrs) • Magnitude of 50-year rainfall (24 hrs)

Potential Effects Change in magnitude of 100-year rainfall

Flagstaff

Phoenix

Tucson

• Incidence/severity of:

– Washouts/erosion

– Scour

Lower confidence than for temperature projections

– Mudslides

– Disruptions

Wildfire • Second order effects:

floods, mudflows, landslides, bridge scour

» Reduced vegetative cover (increased runoff)

» Increased debris (greater risk of clogging drainage, channels)

• Operational disruptions

• Deterioration, minor damage to guardrail, pavements

Example Climate Indicators • Average Daily Maximum Temp • Average Seasonal Precipitation

(May-June-July-Aug)

• Aggravate flooding/ drainage failures

• Operational disruptions Flagstaff

Phoenix

Tucson

Potential Effects Wildfire

How Will ADOT Use the Results? • Design standards

Justify use of larger design storm

• Transportation Asset Management Plan

Contribute to risk-based approach

• Strategic Highway Safety Plan

Weather-related incidents

Next Steps: Continued Partnering • Continue coordination with state, federal, and

university partners

• Increase coordination with local governments and MPOs (for detailed area assessments)

• Leverage existing tools with minimal development costs (e.g. USGS StreamStats)

Questions?

Contacts ADOT Project Manager

• Thor Anderson (tanderson@azdot.gov, 602.712.4574)

ADOT Technical Contacts

• Kris Gade (kgade@azdot.gov, 602.292.0301)

• Steve Olmsted (solmsted@azdot.gov, 602.712.6421)

• Charles Beck (cbeck@azdot.gov, 602.712.8628)

Consultant

• Josh DeFlorio (jdeflorio@camsys.com)

FHWA Website http://www.fhwa.dot.gov/environment/climate_change/

Reserve Slides

Biotic Communities in the Project Corridor

Goals of pilot study

Data – Transportation Infrastructure Assets (ADOT)

• Feature Inventory System

• Bridge Rating System/NBI

• Culvert capacity data

• Roadside vegetation, stabilization, habitat

– Stressor Data and Models • Projections of Temperature and Precipitation Extremes

• Land cover

• Hydrological modeling

• Dust storm models?

– Criticality • Economic importance

• Transportation alternatives

Scenarios: Transportation Parameters

• Sensitivity Thresholds

– Focus on extremes (e.g., 100-year rainfall)

– Exceedance Values (e.g., 3.5” of rainfall)

– Temporal Frames (e.g., 24 hours)

– Frequency/Recurrence (e.g., 1% chance)

• Analysis/horizon year(s)

– Long Range Planning (e.g., 2040)

– Asset lifespan (e.g., bridge, 50-75 years)