Extreme Weather and Climate Change Vulnerability Assessment of Central Texas Transportation Infrastructure

Transcription

1 Extreme Weather and Climate Change Vulnerability Assessment of Central Texas Transportation Infrastructure Federal Highway Administration (FHWA) Pilot Project TxDOT Transportation Planning Conference June 4, 2014 Capital Area Metropolitan Planning Organization City of Austin, Office of Sustainability Cambridge Systematics, Inc.

2 FHWA Pilot Project Two types: Vulnerability Assessment Pilot Adaptation Options and Integration Completion Date September 2014 Evaluate transportation assets CRITICALITY TO REGIONAL TRANSPORTATION VULNERABILITY TO EXTREME WEATHER EVENTS Use and share results Transferable methodology 2013 Vulnerability Assessment recipients: Alaska DOT Arizona DOT Capital Area MPO (CAMPO) Connecticut DOT (ConnDOT) Iowa DOT Maine DOT Michigan DOT Minnesota DOT (MNDOT) North Central Texas Council of Governments Tennessee DOT (TDOT)

3 Project Partners CAMPO City of Austin, Office of Sustainability Williamson, Travis, Hays, Bastrop, Burnet and Caldwell counties TxDOT, Capital Metro City Departments: Transportation Department, Public Works, Homeland Security and Emergency Management, Capital Planning Office Lead Consultant: Cambridge Systematics FHWA

4 Project Objectives Assess the vulnerability of the region s transportation system to the impacts of extreme weather Incorporate results into the 2040 planning process to increase extreme weather resiliency, now and in the future Nature of the results will determine how they are incorporated into the 2040 Plan Share results with partner jurisdictions, agencies and the public

5 Project Area PROJECT AREA POPULATION (April 1 st, 2013) CITY OF AUSTIN: 842,750 REGIONAL: 1,870,872 REGIONAL 2035: 3,250,000

6 Project Scope Regional transportation system (6 counties) Highways, bridges, rail, aviation, transit Existing and planned facilities through 2040 Extreme weather: Precipitation, temperatures, wildfire, drought

7 Physical Characteristics UNIQUE FEATURES TOPOGRAPHY & GEOLOGY WEST - ROCKY HILL COUNTRY EAST FLAT, SOFTER SOILS SOURCE: GEOLOGIC ATLAS OF TEXAS, TEXAS WATER DEVELOPMENT BOARD SOURCE: CAMPO, FEMA

8 Soil Plasticity Clay soils on the east side have high soil plasticity Causes pavement, road bed and utility problems when soil expands and shrinks with varying soil moisture

9 Impacts of Extreme Weather Sinkhole Buckling roads Aftermath of wildfire Drought: Disrupted Water High winds Wildfires Flooding: Tropical Storm Hermine Fallen tree

10 Project Approach Task I Select/Characterize Assets + Asset Criticality Task II Identify Climate Variables to Study Task III Assess Vulnerability + Integrate Vulnerability

11 Asset Criticality Assessment Guiding principles critical assets selected for evaluation should: Provide regionally-significant access and connections Reflect the region s multimodal system Take into account the region s extreme weather vulnerabilities Broadly represent similar assets Consider geographic and social diversity

12 Critical Assets for Further Evaluation

13 Critical Assets for Further Evaluation Potential Evacuation Recommended Asset for Evaluation County Vulnerabilities AADT Route? US 290E at Johnny Morris Road Travis F, D, H 38,000 MetroRail Red Line at Boggy Creek Travis F, D, H N/A SH 71E at SH 21 Bastrop F, D, W, H I-35 at Onion Creek Parkway (including Old San Antonio Road low water crossing) 27,000 (SH 71) 9,500 (SH 21) Travis F, H 186,000 US 290W/SH 71 Y at Oak Hill Travis F, D, W, H Loop 360/RM 2222 Travis F, D, W, H FM 1431 at Brushy Creek/Spanish Oak Creek US 281 and SH 29 Intersection Burnet F, H 38,000 (US 290W), 29,000 (SH 71) 40,000 (Loop 360) 44,000 (RM 2222) Williamson F, D, H 30,000 11,000 (US 281) 11,000 (SH 29) US 183 north of Lockhart Caldwell F, D, H 13,000 SH 80 (San Marcos Highway) at the Blanco River Hays F, H 9,500 Potential vulnerabilities: F: Flooding, D: Drought, H: Extreme Heat, W: Wildfires

14 Extreme Weather Sensitivities in Central Texas Asset Type Flooding Drought Extreme Heat Cold/Ice Wildfire Roads Major impact, especially on rural Cracking, failures on edge of pavement; soil Some cracking and degradation, Hazardous roadway Disruption; Low short-term impact on roads (disruption, destabilization if roadside especially on edge conditions; pavements; washout) vegetation affected of pavement cracking on longitudinal joints destruction of guardrail and sign posts Bridges Minimal impact, except where heavy debris and sediment loads Minimal impact Minimal impact Hazardous driving conditions, icing Rail Service interruptions Minimal impact Speed restrictions, delays during extreme heat; risk of thermal misalignment Transit (bus) Routes disrupted, but may have ability to detour Legend Damage to routes, but may have ability to detour A/C issues in high heat Damage to switches Risks to passenger health at stops Major Impact Moderate Impact Lesser or long-term impact Minimal or no impact Operational disruptions Major impact, if exposed Operational disruptions

15 Extreme Weather Sensitivity Thresholds in Central Texas Impact Flooding Pavement cracking or other deterioration Thermal misalignment Mode(s) Affected Highways, Rail, Transit Highways Threshold General flood risk increases when rainfall > 2 in less than 12 hours Rural roads: >3.44 in 24 hours Principal arterials: > 7.64 in 24 hours Major highways: > 10.2 in 24 hours Extended temperature > 100 F (empirical) Average 7-day maximum temperature > 108 F (design) Drought lasting longer than 14 days Alternating wet and dry weather patterns, cycling between a few days or weeks Extremely wet conditions for > 1 month Temperatures < 50 F Rail Risk increases when surface temperatures > F

16 Extreme Weather Sensitivity Thresholds in Central Texas (cont d) Impact Mode(s) Affected Threshold Air conditioning stress and failures Rail, Transit Temperature > 100 F Limited ability for maintenance and construction work Highways, Rail, Transit Temperature > 100 F Icy, unsafe road Highways Surface temperature 32 F and precipitation (any) conditions Damage to switches Rail Temperature 32 F and precipitation (> 3/16 of ice) Wildfire Highways, Rail, Transit KBDI 575 Relative humidity < 20% Winds > mph La Niña conditions favoring Southern Plains Wildfire Outbreaks

17 Obtain Climate Data (2040) Focus on extreme weather sensitivity thresholds Weather Research and Forecasting Model (WRF) Data at 30km resolution Dr. Kerry Cook, UT- Austin, leading climate data team Sample output: Observed annual mean temperature (C)

18 Accounting for Model Uncertainty Scenario 1: Values as predicted by the Regional Climate Model Scenario 2: Take values from the regional climate simulations, but for a location 200 (miles) to the north. Scenario 3: Take values from the regional climate simulations, but for a location 200 (miles) to the west Scenario 1 is the most likely scenario

19 Temperature Changes for Mid-Century Surface Temperature Differences ( F) Scenario 1: 2.9 F Scenario 2: 2.9 F Scenario 3: 2.7 F Austin: 30.3 N and 97.8 W Contour interval = 0.2 F

20 Summer and Winter Mean Surface Temperature Differences ( F) Winter Scenario 1: 2.2 F Scenario 2: 2.2 F Scenario 3: 2.2 F Summer Scenario 1: 3.6 F Scenario 2: 3.4 F Scenario 3: 2.9 F Contour interval is 0.5 F JJA = June, July, August mean DJF = December, January, February mean

21 Precipitation Changes for Mid-Century Annual Differences (%) Scenario 1: 7.5% reduction in annual rainfall (blue triangle = Austin) Scenario 2: 5% increase in annual rainfall (2 degrees of latitude north of Austin) Scenario 3: No change in annual rainfall (2 degrees of longitude west of Austin)

22 Winter Scenario 1: 5% reduction Scenario 2: 5% increase Scenario 3: no change Seasonal Precipitation Differences (%) Summer Scenario 1: 15% reduction Scenario 2: 10% increase Scenario 3: no change

23 Model Hydrological Impacts Leverage vflo (already used for CoA FEWS) Derive extent, depth, and flow of 100-year events Dr. Baxter Vieux, U of Oklahoma (emeritus), leading hydrologic modeling team

24 Some Factors Affecting Flooding Rainfall amount, intensity and duration Structure design and condition Amount of impervious cover Using 2040 Plan population and employment estimates as a surrogate for future impervious cover

25 Next Steps Complete climate and hydrological modeling Evaluate selected critical assets for potential Disruption Deterioration Damage Characterize risk for critical assets and asset types Share results with stakeholders Incorporate results in the 2040 Plan

26 THANK YOU