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Transportation Resilience: Adaptation to Climate Change (2016)

Chapter: APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures

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Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
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Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
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Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
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Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
×
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Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
×
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Page 82
Suggested Citation:"APPENDIX DScenario 3: Drought, Heat, andExtreme Temperatures." National Academies of Sciences, Engineering, and Medicine. 2016. Transportation Resilience: Adaptation to Climate Change. Washington, DC: The National Academies Press. doi: 10.17226/24648.
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77 APPENDIX D Scenario 3: Drought, Heat, and Extreme Temperatures In the past it was one big drought every 10 years, then it came to one drought every five years, and now the trends are showing that it will be one every three to five years. So we are in a crisis alright, that is true. . . . But it’s going to be the new norm. So our responses need to appreciate that . . . there is climate change, and it’s going to affect the people that we work with, the com- munities we serve. —Beatrice Mwangi, World Vision 1 introduCtion Weather and Climatic Phenomena Many areas of the world have experienced massive droughts that have had significant impacts on both the human condition and the stability of the economy and security. A drought is defined as a period of below-aver- age precipitation that results in prolonged shortages of atmospheric, surface, or ground water. Drought is often caused by extreme temperatures often lasting over long periods of time. The primary impacts of drought are on water quality degradation, declining surface and groundwater levels, and land subsidence. Secondary impacts reflect the effects on the economy (such as declining agricultural productivity), effects on natural resources (such as an increased number of wildfires), and the effects of subsequent weather events on environmental conditions (such as large-scale erosion due to the die-off of protective vegetation and increased flooding when it eventually rains again). Extreme temperatures contribute to, but do not neces- sarily lead to, a drought (they must be accompanied by a decrease in precipitation). In the United States, recent heat waves have set records for highest monthly aver- age temperatures, exceeding in some cases records set in the 1930s, including the highest monthly contiguous U.S. temperature on record and the hottest summers on record in several states. As noted in the U.S. National Climate Assessment, the number of extremely hot days is projected to continue to increase over much of the U.S., especially by late century. Summer temperatures are projected to continue rising, and a reduction of soil moisture, which exacerbates heat waves, is projected for much of the western and central U.S. in the summer. Climate models project that the same summertime temperatures that ranked among the hottest 5% in 1950–1979 will occur at least 70% of the time by 2035–2064 in the U.S. if global emissions of heat-trapping gases continue to grow. By the end of this century, what have previously been once-in-20-year extreme heat days (1-day events) are projected to occur every two or three years over most of the nation. (1) In Europe, the Regions 2020 report produced by the European Commission details how

78 t r a n s p o r t a t i o n r e s i l i e n c e modelling results show that annual mean tem- perature in Europe is likely to increase more than the global mean temperature. Until the end of this century the average annual temperature in Europe is projected to increase by 2.5–5.5°C for the A2 scenario, and 1–4°C for the B2 scenario. Southern Europe will be most affected, with con- sistent temperature increases between 3°C and more than 7°C, with warming even greater in the summer. As a result of this the risk of summer drought is likely to increase in central Europe and in the Mediterranean area. Longer periods of droughts and more restricted drinking water availabilities combined with a lower density of health infrastructure might lead to a situation of an increasing risk of mortality, particularly in urban centers and agglomeration zones. (2) Transport Impact Extreme temperatures and drought potentially have a wide range of impacts on the design and operations of the transport system. These impacts can be classified as follows. Design • Instability of materials exposed to high tempera- tures over longer periods of time can result in increased failures, such as pavement heave or track buckling. Pave- ments, in particular, are very sensitive to temperature. • Ground conditions and less water saturation (due to drought conditions) can alter the design factors for foundations and retaining walls, such as is occurring with the loss of permafrost in Alaska. • Encased equipment such as traffic control devices and signal control systems for rail service might fail due to higher temperatures inside the enclosure. Operations • Increased electricity usage and power outages dur- ing heat waves might affect the electrical power supply to rail operations and supporting ancillary assets (such as electronic signing) for highway operations. • Low water levels could significantly curtail barge operations along major river arteries as well as lock and dam operations. • Extended periods of high temperatures will affect safety conditions for employees who work long hours outdoors, such as those working on infrastructure recon- struction and maintenance activities. • Right-of-way landscaping and vegetation will have to be more drought resistant and able to survive longer periods of high temperatures. • Other water-use activities in a transportation agency might have to be curtailed, at least on a tempo- rary basis (e.g., washing of transit vehicles). • Extreme temperatures will create dangerous con- ditions for many users of the transportation system, placing greater emphasis on the use of air conditioning for transit vehicles and stations and on increased use of green design approaches. • Extreme temperatures could result in increased maintenance activities, such as replacing tracks that have buckled and pavement sections that have experienced heave, as well as removing landslides and erosion that occur with extreme precipitation events after drought or extreme temperatures have dried out the soil. • Drought-induced wildfires and/or dust storms can create dangerous blackout conditions for road users. • Airplane operations in high-temperature environ- ments might have to be reconsidered due to less lift avail- able in higher elevations to allow a plane to take off. (In Phoenix, Arizona, flights were cancelled due to extreme temperatures and officials’ concern that the runway was not long enough for the planes to take off.) • Extended periods of high temperatures will likely result in changes in rail operations, at a minimum requir- ing mandatory reduced speeds in areas where the track has been exposed to high temperatures over many days. • Similarly, extended periods of high temperatures will negatively affect bicycle use and the desire and pro- pensity of individuals to walk outdoors. Temporal Focus Unlike some other extreme weather events, extreme temperatures and drought can be predicted with some certainty and prepared for. Climate models, for exam- ple, are fairly consistent in their projections of where higher-than-historical temperatures are likely to occur in the world. Extreme temperature and drought conditions usually become serious when they persist over extended periods, and with the “blocking systems” meteorolo- gists talk about, these periods of extreme conditions are lengthening. The longer an event lasts, the more impact there will be on the economy, the human condition, and system operations. During an extended extreme weather event, transport officials should aggressively dissemi- nate information to transport employees and to the rid- ing public on the strategies they should use to minimize heat-related complications. The transport agency should monitor the conditions of key assets, such as track, road segments, locks and dams, and other key facilities, at a much more frequent schedule than usually occurs during

79A P P E N D I X D : s c E N A r I o 3 : D r o u g h t , h E A t , A N D E X t r E m E t E m P E r A t u r E s the normal asset management program. For example, rail transit agencies might have to monitor track condi- tion and the potential occurrence of rail buckling or train breakdowns (especially in tunnels) on a weekly or daily basis. 2 desCriPtion of the Case: CatastroPhiC heat wave hits metroPolis Background Metropolis is a major metropolitan area and economic center in the nation. It is a major port city with inland waterways (including locks) connecting to the hinter- land. Because of the economic significance of the port, three major national railways serve Metropolis along with a major international airport for both passengers and cargo. The most recent population census indicated that just over 8 million people live within the urban area, with a major portion of the population representing mid- to low-income households. The central city is well-served by a metro rail network and has good intercity rail con- nections to the rest of the nation. There are 1,500 buses in the bus fleet, with 58 metro stations. Metropolis is a growing region, thus experiencing significant demands on government agencies to provide the infrastructure and services needed to serve this growth. As is typical in many urban areas, inadequate investment has occurred in such services due to the limited amount of available funding. Being on the coast, Metropolis has experienced some significant storms that have inundated the coastal areas. Popular concern in the region for climate change has thus focused on sea level rise, storm surge, and flood- ing. Very little attention has been given to the implica- tions of other extreme weather events. However, the region has experienced five straight years of below- average rainfalls, so water levels are down everywhere. Metropolis University climate scientists have been warn- ing about the possibility of extreme temperature events, but to date not much policy or public attention has been given to such a possibility. Metropolis Transport (MT) is responsible for the transit system in the region. The Metropolis Highway Administration (MHA) is respon- sible for the major highway network, and 85 different transport agencies are responsible for local roads, side- walks, and paths. The Metropolis Airport Authority is responsible for the airport and its operations. MHA has placed intelligent transport systems technology through- out the region to provide the most up-to-date monitoring and user information systems. The Metropolis Planning Agency is responsible for regional planning, but it has no implementation authority over the regional or local gov- ernments. The most recent climate change–related topic in the regional transportation plan focused on sea level rise and extreme precipitation events. The Event The national weather service issued warnings at the beginning of the year (6 months ago) that the summer could be unusually hot. Two months ago the tempera- tures started to reach above 95°F (35°C) for the first time. The temperature has reached 100°F (38°C) for the past 30 consecutive days, with the weather service predicting that these extreme temperatures will likely last for pos- sibly another month or month and a half. The impact of these temperatures on Metropolis has been dramatic. There has been a major upswing in heat-related deaths, especially among older people. Shelters have been opened for individuals not having air conditioning in the home or who are homeless. Levels in the Metropolis reservoir have never been so low, and water rationing has been instituted for both business and residential uses. Power surges during the day have caused five brownouts dur- ing the last month, and the Metropolis Utility District (MUD) has warned that more will likely occur as long as the heat wave continues. The mayor has suggested that MUD negotiate to purchase power off of the grid, but MUD officials say the local grid network is unable to handle the increased demand. Two months ago, light- ning strikes caused the Metropolis National Forest, some 100 miles away, to erupt in wildfires, catalyzed by the extremely dry forests. Massive smoke plumes from these fires reached the city, and large amounts of land were left barren. There is great concern about erosion once heavy precipitation events return. Transport Impacts At first, the heat wave had little impact on Metropo- lis’s transport system. After 2 months, however, trans- port officials started getting indications that the heat wave was affecting operations. Several transit passen- gers collapsed at bus stops and in transit stations due to heat-related symptoms. The air conditioning in several underground transit stations stopped due to maintenance issues, resulting in very high temperatures in the station area. Twenty percent of the bus fleet began to experi- ence air conditioning problems as well, resulting in an avalanche of customer complaints about the bus condi- tions. Several transit construction projects were delayed due to the unbearable working conditions for the con- struction workers. Perhaps most surprising (especially to MT officials) was the buckling of rail track on two of the major metro lines due to excessive heat. Luckily, MT had stockpiles of replacement track, and the track was

80 t r a n s p o r t a t i o n r e s i l i e n c e reopened in one day, minimizing disruption. Electrical systems, which were a peripheral but critical part of the transportation systems, were tied to the region’s electric- ity grid and began to fail as the brownouts continued. The biggest public relations issue for MT related to the use of its facilities by the homeless and those without air conditioning as a means of coping with the extreme heat. Initially, MT enforced its rules of “no loitering” and “one ticket–one ride,” thus removing from its facili- ties and services those who had nowhere to go. Public outrage over “putting citizens at risk” quickly caused MT to temporarily suspend these rules for the duration of the crisis. MT officials quickly realized they were part of the human impact story and initiated efforts to take care of those seeking shelter from the heat wave, includ- ing providing free transport to other shelters that had been established in Metropolis to handle such demands. MHA had assumed the pavement design used for its major highways could withstand extended periods of high temperatures. In fact, this was true. However, the pavements on several minor highways experienced pave- ment heave, shutting down the roads for approximately 4 days. Given the nature of the highway network, the drivers on these roads were able to find alternative routes to their destinations. Some businesses in these highway corridors were disrupted due to interrupted freight deliv- eries, but they were able to find alternative locations for the deliveries to be made. The biggest impact on the highway network (again to the surprise of the agency responsible for it) was the breakdown of the intelli- gent transport system due to many of the assets being unprotected from extreme heat. Overhead signs, surveil- lance cameras, and many traffic signals were shut down because of equipment malfunction. The MHA minister was quoted on local television as saying that this level of disruption was unforeseen, but that MHA officials were replacing the equipment as fast as they could. Similar to MT, several MHA construction projects were curtailed during daytime hours due to unbearable heat for con- struction workers. MHA was also constrained by legal limits on the maximum temperatures at which people can be allowed to work, and the agency instituted con- tract negotiations to see if construction could occur at night. Several sectors of the Metropolis economy were beginning to be affected because of the potential dis- ruption to transportation services. Water levels on the major inland waterway were so low that major barge operators were warning that barge operations might be curtailed. This possibility was not a serious issue because some commodities could be transported by truck or rail (although freight rail operators were also concerned about rail buckling and had lowered their speeds on sec- tions of track that were considered most vulnerable). However, for bulk commodities, such as coal and agri- cultural products, the limitation on barge operation was potentially an economic disaster. The MHA did notice an appreciable increase in large trucks on the major high- ways in the region due to the shifting of freight modes, causing increased levels of congestion. Metropolis Air- port Authority announced that the airport was still oper- ating without delays, but that if the heat wave continued limitations on plane departures might have to be insti- tuted. This possibility was not considered to be a major disruption because flights could be rescheduled (if the airlines agreed) to hours when the heat would not affect operations. The Press Not surprisingly, the media and press focused on the human element of the heat wave story. How many heat- related deaths have there been? How are people coping? What is the government doing to help those in need? However, as disruptions to the transport system contin- ued to grow, reporters began to question why the trans- port agencies were so unprepared for the impacts of the heat wave on the transport system. Why did so many bus air-conditioning units fail? How could transport agen- cies design pavements and MT design track that could not withstand extended high temperatures? Given that national, metropolitan, and local transport agencies are responsible for similar types of infrastructure and ser- vices, why had there not been any coordinated planning and foresight on how transport agencies should prepare for and respond to heat waves? Most importantly, what are these agencies going to do to avoid these disruptions in the future? The Aftermath National, state, and Metropolis officials decided to draw important lessons from the drought experience. It was realized that transport officials could take steps to pre- pare for the likely impacts that higher temperatures and droughts could have on transport infrastructure and sys- tem operations. The steps taken included the following: • Establish a climate change task force that will be responsible for identifying vulnerable assets for all pos- sible climate change–related stressors facing the trans- portation system in Metropolis, based on the best science available. The task force is also mandated to develop a coordinated and collaborative institutional response strategy when a climate-related emergency is declared. • Engage the local university to examine carefully the behavior of materials under extreme temperatures to determine vulnerabilities. It is likely that in the short

81A P P E N D I X D : s c E N A r I o 3 : D r o u g h t , h E A t , A N D E X t r E m E t E m P E r A t u r E s term (i.e., 10 to 20 years), many of the design and mate- rials specifications for transport infrastructure will result in assets that can withstand higher temperatures over extended periods. However, it is not clear that the much greater exposure to extended higher temperatures expected in the latter part of the century will have a simi- lar experience. In addition to the university studies, all the infrastructure-related agencies will be jointly under- taking a comprehensive examination of their design standards to assess their relevance in a future that could be very different than the past. • Develop a strategy to comprehensively moni- tor asset performance to identify when stress levels are approaching dangerous levels (this approach most likely will use sensors and “smart” materials to provide advance warning of stresses caused by unusual envi- ronmental conditions). Prepare contingency plans to respond to heat-related asset stress emergencies (e.g., establish detour routes for potentially vulnerable critical network links). Assets and materials that might be most susceptible to heat extremes will be stockpiled to mini- mize the replacement time to restore service. • Reexamine operating and maintenance procedures to assess likely changes in light of recent experience with drought and high temperatures. For example, the MHA executive director wanted to know if more drought- resistant vegetation could be used in rights-of-way to avoid replacing any that succumbs to drought (and perhaps save funding by not requiring as much main- tenance). In addition, MHA was examining new design standards for drainage and erosion control in antici- pation of massive erosion near roads adjacent to the burned-out portions of the Metropolis National Forest. • Examine sensitive equipment with respect to high temperatures, and identify strategies for protection. • Examine how transport agencies could respond to the human element of system operations (e.g., increased shade and air conditioning in service areas, and more rests and water breaks for construction workers). This area of interest had been considered by very few officials. • Develop marketing and public information materi- als to educate system users on how to handle heat-related service disruptions. • Seek knowledge and experience from transport officials working in different climatic zones, especially in those areas already experiencing drought and high tem- peratures—there is no need to reinvent the wheel. 3 issues raised by the Case Level of Preparedness for the Event Public officials had focused on those climate change stressors that had been experienced via past storms and that had received the most public attention, giving lit- tle attention to extreme temperatures. Transport agen- cies had not anticipated or prepared for the challenges related to higher temperatures. An example of this lack of preparation was the transit system’s experience with air-conditioning breakdowns on transit vehicles. Interdependence with Other Critical Infrastructures The region’s rail transit system was dependent on the elec- trical grid and was thus affected by the much-higher-than- normal electrical demands. The constraint on barge traffic due to low water levels had a domino effect throughout the economy, as well as on the transport system. Severity of the Transport Impacts The severity of impacts on the transport system var- ied with the extent to which assets and infrastructure were sensitive to prolonged higher temperatures (such as rail track) and the degree to which network redun- dancies provided system resilience (such as the aviation network). Some impacts (such as nonworking air- conditioning units in transit vehicles) were minor nui- sances; others (such as the electrical shutdowns) caused major network breakdowns. Extreme temperatures may also increase absenteeism in the transport workforce. User Groups Affected From a transport perspective, the primary groups affected were users of the system, in particular those who were exposed to higher temperatures, such as transit users. Others were affected because services that transport systems provided were curtailed or inter- rupted (such as the impact on the economic sector due to more constrained barge transport). The big surprise to transport officials was the degree to which they became part of the “bigger story” of how people were surviving the extended heat wave, that is, how their facilities and vehicles became a refuge for those seeking relief from the heat. Management of the Event by Various Stakeholders There was little coordinated planning among the many transport agencies relating to extreme heat issues, even when the transport agencies were responsible for simi- lar assets (e.g., both the highway and transit agencies

82 t r a n s p o r t a t i o n r e s i l i e n c e were responsible for pavements and structures). Until the press highlighted the seemingly uncoordinated nature of transport agencies’ responses, agency officials had not discussed and certainly had not coordinated common response strategies. Observed Levels of Resilience The level of resilience of different transport networks varied by mode. The aviation network was able to respond quickly, and the transit agency (MT), which was equipped with prepositioned rail supplies when track buckling occurred, was also able to respond quickly. Others, such as barge transport, showed very little resil- ience because of the long-term nature of the disruption (low water levels) and the inability of alternative modes to economically and efficiently carry the types of com- modities most often transported by barges. Some of the obvious substitute capacity, such as rail, could experi- ence its own problems, especially as the extreme heat could also reduce this capacity (e.g., through lower speed limits and equipment breakdowns). Public Attention Because of the visibility and importance of the transport system to Metropolis citizens, it became the focus of media attention very early in the crisis. This attention caught transport officials by surprise; the agencies’ press information offices were unprepared to answer extreme heat–related questions from the press. The public infor- mation aspect of the crisis had been completely over- looked by the transport sector. 4 researCh Questions • What are the extreme heat–related stresses that are likely to affect normal transport system operations and ultimately affect other sectors? • What are the steps in an infrastructure vulnerabil- ity assessment related to extreme heat? • How does one identify the interdependencies among different sectors and infrastructures in order to pinpoint potential failures? • How can different modal transport agencies col- laborate and coordinate their responses to extreme heat– related events? • What advances in materials properties are neces- sary to create materials that can withstand long periods of extreme heat? • How can “smart” materials be used to monitor asset condition to identify potential failure due to heat? • What non-material-related strategies should be considered to protect critical assets from extreme tem- peratures? • From a crisis management perspective, how can transport agencies become involved with the “total pic- ture” in terms of societal response? referenCes 1. U.S. National Climate Assessment. http://nca2014.glo balchange.gov/report/our-changing-climate/extreme- weather. 2. European Commission. Regions 2020: The Climate Change Challenge for European Regions. Brussels, Belgium, 2009. http://ec.europa.eu/regional_policy/sources/docoffic/ working/regions2020/pdf/regions2020_climat.pdf.

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Transportation Resilience: Adaptation to Climate Change and Extreme Weather Events summarizes a symposium held June 16–17, 2016 in Brussels, Belgium. The fourth annual symposium promotes common understanding, efficiencies, and trans-Atlantic cooperation within the international transportation research community while accelerating transport-sector innovation in the European Union (EU) and the United States.

The two-day, invitation-only symposium brought together high-level experts to share their views on disruptions to the transportation system resulting from climate change and extreme weather events. With the goal of fostering trans-Atlantic collaboration in research and deployment, symposium participants discussed the technical, financial, and policy challenges to better plan, design, and operate the transportation network before, during, and after extreme and/or long-term climate events.

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