Climate Change Adaptation Planning: Risk Assessment for Airports (2015)

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P A R T I I I The User Guide

39 7.1 Role of the ACROS Tool in Inventory, Risk Assessment, and Prioritizing Adaptation Options The ACROS tool is designed to guide airport staff through a streamlined process to identify current and future climate risk and evaluate and prioritize potential adaptation options while bypassing the need to develop and examine climate models. To develop adaptation strategies without the tool, an airport would need to conduct its own literature review on adaptation strategies, search for available climate data, and analyze asset-relevant adaptation options. With the ACROS tool, much of this research is readily available, as the ACROS tool contains a sub- stantial amount of site-specific information for airport assets with climate change projections, and expert-recommended adaptation options for climate-related impacts. By making use of the ACROS tool, airport managers can significantly reduce the resources needed to initiate the climate change adaptation planning process. For more information about using existing airport planning processes to implement climate change adaptations, please see Chapter 8. 7.2 User Overview The ACROS tool guides a user through the risk screening process. • Step 1: Identify a facility from the national database. • Step 2: View climate hazards data for the airport of interest. • Step 3: Select facility characteristics: – Preselected list of assets and operations will be assumed as a default, but these can be refined by the user. – Airport-specific assets and operations identification are necessary to complete risk screening. • Step 4: Define the importance of asset/operation to the airport system (criticality). • Step 5: Estimate the likelihood of asset/operation failure upon exposure to impacts (vulnerability). • Step 6: Report and printout: – On-screen representation of risk as a factor of changing climate, criticality, and vulnerability. – Ability to print report, including climate hazards, asset risk screening, and potential adaptations. It is recommended that the lead tool user be prepared to consult with airport stakeholders, as needed, for any airport-specific customization. Most users will find that additional input is necessary to complete the criticality and severity sections of the tool, which will be described in more detail below. Key stakeholders might include managers, designers, planners, and other SMEs, such as those responsible for the operations and engineering departments at the airport. Including those stakeholders responsible for managing risks to these categories will be especially C H A P T E R 7 The ACROS Tool User Guide

40 Climate Change Adaptation Planning: Risk Assessment for Airports important. With stakeholder input gathered, the user will be asked to provide information spe- cific to that airport’s assets in Step 3. 7.3 System Requirements and Display Tips • Microsoft Windows 7 operating system and later (note: a Macintosh computer running Boot Camp is not compatible). • Microsoft Windows Office 2007 and later. • Microsoft .NET framework version 4.0 and later. • Suggested resolution for display: widescreen format of 1280 × 800 or higher. • For extended-screen desktops (with two monitors), using the tool on the left monitor is pre- ferred, otherwise pop-up user tips will not align with the ACROS screen. 7.4 Step-by-Step User’s Guide 7.4.1 Installation Click on the application in a network location and use the Setup Wizard to install the ACROS tool. Use the default settings in the wizard (Figure 7-1). Figure 7-1. ACROS installer. The tool will be installed on the computer’s desktop. Double-click to open the application. The shortcut icon is shown in Figure 7-2. Figure 7-2. Desktop shortcut icon.

The ACROS Tool User Guide 41 7.4.2 Welcome Screen The purpose of the first screen is to present introductory information about the tool (Fig- ure 7-3). Click “Ok” to continue to the Airport Selection. Figure 7-3. Welcome screen. 7.4.3 Airport Selection Screen The purpose of this section is to identify your location. Enter the airport’s three-letter FAA identifier into the Search Airport dialogue box (Figure 7-4). Click “Ok” to continue to the Climate Information. Figure 7-4. Search airport dialogue box.

42 Climate Change Adaptation Planning: Risk Assessment for Airports Note: This tool is designed to view one airport at a time. For those users responsible for mul- tiple airports, the tool must be used in separate sessions. To start a new session, please exit and re-open the tool. To save the session you are working on before closing, please see Section 7.5 Saving, Sharing, and Troubleshooting. 7.4.4 Climate Information Overview By using metrics that are relevant to airport asset management concerns, this section provides information about current and projected climate specific to your location. The first screen in this section is a primer on how the Climate Information portion of the tool organizes the climate data that will be displayed. Data sources, units, confidence, and model ranges are briefly dis- cussed. Click “Ok” to continue to the individual climate vectors. For more information on cli- mate vector selection and confidence, please see Appendix D. The explanatory screen is shown in Figure 7-5. Please note that even “low” confidence implies that the vector may still be useful for plan- ning purposes. This low/moderate/high ranking scheme is based on a combination of how well climate vectors matched observation, and how well the suite of models used match one another (model agreement). The high/moderate/low is a comparison between the vectors that were chosen for the study. Only vectors that were able to reliably reproduce observed climate were Figure 7-5. Climate information explanatory screen.

The ACROS Tool User Guide 43 selected for this project, so even a “low” value for a vector included in ACROS contrasts sharply with vectors that were excluded from this tool, like wind and fog. Wind and fog are critical to airport operations, but unlike even the “low” confidence level vectors, current models for these two climate stressors are not yet mature enough to be included in ACROS. For more in-depth guidance on this topic, please see Table 7-1. CLIMATE VECTOR DESCRIPTION CONFIDENCE IMPLICATION OF VECTOR CONFIDENCE FOR ENGINEERING, DESIGN, AND PLANNING Hot Days High temperature ≥ 90°F HIGH The direcon and magnitude of change in these vectors are similar among the models reviewed, and therefore confidence is high. Priorizing resources to manage potenal impacts for highly crical and vulnerable infrastructure and operaons should be incorporated into exisng planning and design documents. Very Hot Days High temperature ≥ 100°F HIGH Freezing Days High temperature ≤ 32°F HIGH Frost Days Low temperature ≤ 32°F HIGH Cooling Degree Days Departure of mean temperature ≥ 65°F HIGH Heang Degree Days Departure of mean temperature ≤ 65°F HIGH Hot Nights Low temperature ≥ 68°F HIGH Humid Days Mean dew point temperature ≥ 65°F HIGH Snow Days Snow accumulaon ≥ 2 in. MEDIUM Some uncertainty exists as to the likely magnitude of change to these climate vectors. Consider projected impacts to high-priority infrastructure associated with the range of potenal change in the future climate vectors presented in the tool when planning and evaluang future resource allocaon. Storm Days Thunderstorm rainfall ≥ 0.15 in. LOW Heavy Rain (1 day) Daily rainfall ≥ 0.8 in. LOW Heavy Rain (5 day) Total 5-day rainfall MEDIUM Dry Days Consecuve days of rainfall ≤ 0.03 in. MEDIUM Sea Level Rise Daily runway flooding (NFDC elevaon) HIGH Incorporate projected SLR into any planned or designed infrastructure or operaons project that is potenally affected by SLR flooding. Sea Level Rise – BFE Relavely infrequent but substanal flooding HIGH Incorporate projected storm surge into any planned or designed infrastructure or operaons project that is potenally affected by storm surge flooding. Wind* Prevailing wind direcon and speed NONE These climate vectors were not included in this project because the direcon and magnitude of the change was not consistent among the models reviewed. However, changes to these vectors could affect airport operaons or infrastructure. If the airport is currently experiencing impacts to crical and vulnerable infrastructure due to these climate vectors, these impacts should be considered in planning and resource allocaon. Fog* Visibility ≤ 0.25 miles NONE *Vector was invesgated, but not included in the ACROS tool due to lack of confidence in exisng models. Should these issues be of interest to an airport, potenal adaptaon opons and planning suggesons are available for reference in Appendix A. Table 7-1. Climate vectors and confidence implications for engineering, design, and planning.

44 Climate Change Adaptation Planning: Risk Assessment for Airports 7.4.5 Climate Projections (days/year) Use the menu along the left side of the Climate information section (shown in Figure 7-6) to view each climate vector. Airport and regional perspectives are presented, showing baseline (historical) conditions, 2030 projections, and 2060 projections for each vector. Note that there are two sections of climate vectors, “Climate Projections” (days/year) and “Additional Climate Projections.” The Climate Projections (days/year) are: • Dry Days • Freezing Days • Frost Days • Heavy Rain (1 day) • Hot Days • Hot Nights • Humid Days • Sea Level Rise • Snow Days • Storm Days • Very Hot Days • Cooling Days • Heating Days These vectors are all shown in the common unit of days per year and contribute to the risk score of related impacts. Because having a common point of comparison to understand changes to the climate vectors is advantageous, the unit for most vectors shown in the tool is days. 7.4.6 Additional Climate Vectors “Additional Climate Vectors” provide vectors in units pertinent to specific professional disci- plines, such as Cooling and Heating Degree Days, which are of interest to HVAC professionals. This second category of climate vectors was included because it is acknowledged that many disci- plines (e.g., building sciences and HVAC) may find it useful to review projected climate changes reported in terms commonly used in those fields. Thus, the following vectors are also reported: • Cooling Degree Days (cumulative degree days) • Heating Degree Days (cumulative degree days) • Heavy Rain (5 day) (inches) • Sea Level Rise–BFE (feet) Note: With the exception of Sea Level Rise and Sea Level Rise–BFE (coastal vectors), all climate vectors are reported for all locations in the U.S. Due to the wide range of climates in the U.S. (arctic, temperate, sub-tropical, and tropical) not all vectors may be relevant to certain climates, and the user may consequently choose to focus on the most relevant vectors. For example, the Snow Days vector has limited applicability to tropical climates, and Very Hot Days (days with temperatures exceeding 100°F) has limited applicability to northern climates (e.g., much of the Northeast and Alaska). 7.4.7 Coastal Vectors At coastal airports, the ACROS reports SLR hazard changes using one or both of the following vectors, which are defined below and depicted in Figure 7-7 and Figure 7-8. • Sea Level Rise: Increased nuisance flooding • Sea Level Rise–BFE: Projected changes to the base flood elevation in the Special Flood Hazard Area (the 1-percent-annual-change flood elevation, also known as the elevation of the 100-year event)

Figure 7-6. Airport-specific and regional climate projections.

46 Climate Change Adaptation Planning: Risk Assessment for Airports Figure 7-7. Airport campus is within the Special Flood Hazard Area and is also affected by nuisance tidal flooding and/or permanent inundation. For an airport in this type of location, the ACROS tool reports both the Sea Level Rise–BFE and Sea Level Rise vectors. Figure 7-8. Airport campus is within the Special Flood Hazard Area but is not affected by nuisance tidal flooding. For this situation, the ACROS tool reports only the Sea Level Rise–BFE vector. The Sea Level Rise vector will be grayed out.

The ACROS Tool User Guide 47 More coastal airports will have values for the Sea Level Rise–BFE vector than for the Sea Level Rise vector. Sea Level Rise–BFEs represent the 1% annual chance flood elevation— a relatively extreme and infrequent event as compared to nuisance flooding. BFEs are much higher than nuisance flooding levels and will impact much more land area of higher topographic eleva- tions. Due to this, more coastal airports will have values for the Sea Level Rise–BFE vector than for the Sea Level Rise vector. A small number of lower elevation coastal airports will have values reported for both Sea Level Rise–BFE and Sea Level Rise. For this project, airports at risk to SLR were defined based on runway elevation reported in the NFDC database. SLR information is therefore shown for some airports that may already have levees (e.g., OAK and MSY), but will not be shown for some airports that may still have concerns about SLR. 7.4.8 Asset and Operation Information This section records which assets and operations are present at a particular airport for later use in the climate impact risk screening. This section is a simple checklist interface, with some common assets and operations already checked. Here are a few display tips that may be helpful: • In this section, as well as the Criticality, Vulnerability, and Screening sections, it is possible to sort alphabetically by Service, Asset/Operations, or other categories by clicking on the heading. • Each screen is composed of several tiles, for example, the Information tile and the Assets/ Operations tile, where users inventory their assets and operations as depicted in Figure 7-9. To widen the tile that is being used, click the nested box icon in the upper right corner of the tile. • Column sizes may also be adjusted by clicking and dragging. For more information, please refer to the instructions in Figure 7-10. These instructions are also shown on the Assets screen in the tool. Figure 7-9. Screen tiles and expansion icon.

48 Climate Change Adaptation Planning: Risk Assessment for Airports 7.4.9 Defining Criticality The purpose of this section is to determine asset and operation criticality, which is defined in the instructions below. After completing the Assets section above, use the left side panel to navigate to the Criticality section (Figure 7-11). Figure 7-10. Asset and operation inventory instructions. Figure 7-11. Navigation menu—criticality. Figure 7-12. Criticality definition and instructions. (continued on next page) Only assets and operations selected in the previous Assets section are shown on this screen. Pre-assigned default values may be modified by the user. Airport user groups are encouraged to define criticality internally, although a sample definition is provided in Figure 7-12.

The ACROS Tool User Guide 49 Figure 7-12. (Continued). Figure 7-13. Navigation menu—vulnerability. 7.4.10 Understanding Possible Climate Impacts and Defining Impact Vulnerability The purpose of this section is to present impacts that are applicable to the selections in the Assets section based on the changes in climate vectors at the airport location. After completing the Criticality section, please use the left side panel to navigate to the Vulnerability section (Figure 7-13). This section is central to completing the risk screening. In the Vulnerability section of the tool, only climate-related impacts that satisfy both of the following conditions are shown: a) Change to the climate vector is significant (changes to this vector exceed 0.5 days per year), and b) The impacts related to this climate vector are applicable to the assets and operations selected in the previous Assets section. The initial screen, shown in Figure 7-14, emphasizes that this section is the keystone for the risk screening. After reading this opening screen, click “Ok” to continue to proceed to the vulnerability assessment. The definition of vulnerability, as well as instructions for choosing the vulnerability values of potential impacts, is shown in Figure 7-15. The user may modify the pre-assigned default values. 7.4.11 Risk Screening Page This section shows the risk to each asset (relative to all other assets at the airport) from chang- ing climate at 2030 and 2060. After completing the Vulnerability section, please use the left side panel to navigate to the Screening section (Figure 7-16).

Figure 7-14. Vulnerability information screen. Figure 7-15. Vulnerability definition and instructions.

The ACROS Tool User Guide 51 The right panel shows a key for the Screening information. Each asset or operation is scored using the three-color relative risk scheme shown in Figure 7-17. Icons associated with climate impacts are also defined. Figure 7-16. Navigation menu—screening report. Figure 7-17. Risk and climate vector key. Figure 7-18 shows a sample output. When an asset or operation is selected, the bottom right panel, as shown in Figure 7-19, provides adaptation information on individual assets or operations. Click on an asset or opera- tion on the left-hand side of the screen to see which climate vectors are responsible for which impacts, the risk level relative to other assets and operations at the airport, and possible adapta- tion options. The key indicates which climate vectors are responsible for each impact. The air- port planning processes for which further assessment and adaptation selection can be pursued are provided in the appendices. 7.4.12 Printing a Report This section provides instructions on creating a Word version (.docx) of the report. Please use the left side panel to navigate to the Reports section (Figure 7-20).

Figure 7-18. Risk screening overview—desktop view.

The ACROS Tool User Guide 53 The report sections will be displayed on screen. Simultaneously, the tool will generate a Word (.docx) version of the report containing the following elements (see Figure 7-21 for excerpt): • Climate change summary table, • Individual climate vectors, and • 2030 and 2060 risk, including assigned criticality and vulnerability. 7.5 Saving, Sharing, and Troubleshooting 7.5.1 Saving an ACROS Work Session Select File > Save and use the dialogue box to name the file in a directory the user can access (Fig- ure 7-22). To resume work on the saved file, open the ACROS tool first, and then navigate within the tool using File > Open to the file directory where the ACROS work session was saved. Figure 7-19. Vectors responsible for climate stressors, impacts and risks, and adaptation options. Figure 7-20. Navigation menu and status bar—report.

54 Climate Change Adaptation Planning: Risk Assessment for Airports RISK SERVICE: ASSET: Utilities Water Distribution Systems Risk Climate Vectors Impacts Adaptation Options Dry Days Failure of Underground Utilities From Expansive Soils • Modify Fill Material • Replace Duct Banks Utilities to Alleviate Expansion Dry Days Less Water Main Flushing • Continue Monitoring and Disinfection of Water Supply System Dry Days Reduced Water Availability Due to Drought • Utilize Water Conserving Fixtures and Landscaping Figure 7-21. Excerpt from risk report. Figure 7-22. Save dialogue. 7.5.2 Sharing an ACROS Work Session It is possible to share a copy of a saved ACROS work session. After saving, users may: • Attach the file in an email • Save a copy on a shared network site • Place a file on an ftp or cloud resource Files opened by the ACROS tool are locked, so files can be modified by only one user at a time. 7.6 Understanding ACROS Climate Results 7.6.1 Projected Changes As shown in Figures 7-23 and 7-24, climate vectors are presented in bar graph form. Users are encouraged to examine the median, upper, and lower boundary of the projections as shown in the bar graphs. It is useful to understand the following aspects of the information shown. • Trend: Does the projection call for an increase or decrease in the climate vector shown? • Timing: What changes are projected in 2030? 2060?

The ACROS Tool User Guide 55 • Rate of change: How large a difference between changes is projected in 2030 and 2060? Does the change appear to be linear (a straight-line increase from baseline) or accelerating? • Direction of change: Is the vector projected to increase or decrease? • Confidence: What is the reported confidence in the climate vector? (During an ACROS work session, the user will find this information reported in the “Confidence” icon for each vec- tor in the heading with the vector name and definition.) Remember that “low” confidence does not indicate unusable information, but rather that there is some disagreement in the models about the extent and direction of change. Therefore, decision makers should consider a wider range of possible future conditions than in vectors with higher reported confidence. Table 7-1 considers in greater detail the implications of confidence for planning, engineering, and design. • Regional perspective: How do the changes projected for the airport compare to changes throughout the region? Are there neighboring airports to consider? If so, it may be worthwhile to discuss impacts, experiences, and best practices with officials at those airports. 7.6.2 Interpreting Projected Changes • Compare changes to similar vectors. Example: Most locations will show changes in all tem- perature vectors; however, some changes may occur at different rates than others. It may be useful to graph changes, as shown in Figure 7-25. Figure 7-23. Climate vector bar graph showing baseline and projected values for 2030 and 2060. Bar chart indicates median GCM suite output and whiskers indicate the 25th and 75th percentile outputs, showing a range of model values. Figure 7-24. Site-specific changes in BFE at a U.S. airport reflecting current baseline and projections for 2030 and 2060. Bar chart indicates the intermediate-high SLR estimates and whiskers indicate the low and high estimates.

56 Climate Change Adaptation Planning: Risk Assessment for Airports • Note changes in vectors measuring opposite conditions. For example, nationally, many loca- tions will see increases in Dry Days as well as Heavy Rain 1-Day and Heavy Rain 5-Day events. To some degree, this reflects the less frequent, but more intense, precipitation events that many areas of the United States are already experiencing. • Be aware that change to a climate vector can be responsible for a range of different weather conditions. For example, warming temperatures in areas that experience significant winter precipitation may result in less icy conditions as a result of warmer temperatures, or icier conditions because of changes of precipitation type from snow to freezing rain and sleet. • The ACROS tool presents information directly relevant to airport operations (e.g., an increase in days with 90°F temperatures has implications for the health and safety of outdoor staff and customers). However, because of the complexity and regionally-specific information required, ACROS has limited ability to provide insight into changes in extreme events such as droughts, hurricane frequency, and nor’easters. Additional modeling is necessary to fully investigate events of this type. • Even small changes may be important. Below are two examples: – The rain vectors (Heavy Rain 1-Day and 5-Day) show changes of only 1 to 2 days (some- times less) by 2030 and 2060 at many locations nationwide; however, changes to the design storm may be significant. Depending on the importance of heavy rain events for the airport location, downscaling climate data and investigating possible changes to the design storm may be desirable. – For the Sea Level Rise–BFE vector, it is important to note that BFEs are by convention rounded to the whole foot. Therefore, small increases in sea level may not result in a change to the BFE. 0 10 20 30 40 50 60 70 80 90 B A S E L I N E 2 0 3 0 2 0 6 0 D A YS P ER Y EA R YEAR CHANGES IN TEMPERATURE VECTORS Very Hot Days Hot Days Freezing Days Frost Days Figure 7-25. Example graph of changes in temperature vectors.