H Haazzaarrdd V Vuullnneerraabbiilliittyy ttoo P Peeooppllee aanndd P Prrooppeerrttyy iinn tthhee Sims Bayou Watershed of Houston, Texas April 2015 by *Philip Berke, Professor, Director, Institute of Sustainable Coastal Communities *Chi Huang, Doctoral Student *Jaekyung Lee, Doctoral Student *Galen Newman, Assistant Professor 0 Acknowledgements: Produced by Resiliency and Climate Change Cooperative Project, Institute of Sustainable Coastal Communities, Texas A&M University. Table of Contents Why Study Physical Vulnerability? 2 Why Study Sims Bayou? 2 Study Objectives 3 Next Steps: Neighborhood Involvement 3 What is Hazard Vulnerability? 3 Appendix A: Methodology 5 Appendix B: Maps See attachment References 22 1 Hazard Vulnerability to People and Property in the Sims Bayou Watershed of Houston, Texas Why Study Social and Physical Vulnerability? Vulnerability of populations and built environments to hazards significantly influences the ability of communities to anticipate, respond, resist, and recover from hazard events. Vulnerability to hazards is not equal among different population groups. Communities with limited resources often sustain higher levels of loss and their households have limited ability to repair or replace damaged homes and other property. Households without reliable transportation face challenges evacuating to safer areas. Many are forced to seek shelter in facilities that are unsafe and ill-equipped. More vulnerable residents are forced to flee to distant locations and can face a difficult and prolonged recovery due to the dissolution of social networks, extended periods of unemployment, and a complicated federal aid process. Why Study Sims Bayou? The Sims Bayou watershed drains an area of 94 square miles that is highly vulnerable to hazards (see Figure 1). It contains many of the vulnerabilities associated with flooding in the Houston metropolitan area. The Sims Bayou channel serves as a major run-off drainage channel for Houston, one of several channels in the Houston area suffering from flooding and pollution problems as a result of the metropolitan area's unusually rapid growth during the 1970s. Despite flood control programs, the impact of flooding along the bayou is expected to increase as population and economic growth continue in an area characterized by clay soils and flat coastal terrain. Figure 1: Sims Bayou Watershed* *The Sims Bayou watershed covers about 94 square miles. Approximately 83 percent of the watershed is within Harris County and 17 percent is within Fort Bend County. The Harris County portion of the bayou lies within the southeastern part of Houston, Texas. 2 Objectives Study objectives for the Sims Bayou watershed: Identify key areas exposed to flood hazards and future sea level rise; Determine the level of social vulnerability of people and physical vulnerability of buildings in the watershed and compare vulnerability with the rest of the city; and Create maps that show differences in social vulnerability and physical vulnerability in the watershed to determine the variability in capacity to cope with hazards. Appendix A includes a detailed explanation of the methods used to: a) identify land in the Sims Bayou watershed exposed to current flood hazards areas and future sea level rise; and b) determine vulnerability of people and vulnerability of buildings in the Sims Bayou watershed. Appendix B includes a series of maps that visually show the current flood hazards and future areas exposed to sea level rise, and the vulnerability of people and property in the watershed. Next Steps: Neighborhood Involvement We anticipate that information generated by this assessment will represent an initial step in helping communities understand the social and physical context within which a disaster occurs. We expect this study will be used to supplement the preparation of neighborhood-based vulnerability assessments that involve local people affected by hazards in their neighborhoods. Incorporation of experiential knowledge of people who have lived through disasters and who understand how such hazards make them vulnerable can ensure that the assessment is relevant to those who are most vulnerable. Also, meaningful community involvement will help raise awareness of the risks and motivate community members and organizations to act. What is Hazard Vulnerability? Hazard vulnerability includes two core dimensions: Hazard exposure is the potential to coverage of the geographic extent and severity of a hazard in urban areas as illustrated on floodplain maps. Vulnerability comprises the social and physical susceptibility of a community to loss from hazards: o Social vulnerability considers the social and economic characteristics, such as poverty, race/ethnicity, age, and gender of households that will impact their ability to prepare for, anticipate, cope with, and recover from hazard events. For example, age affects vulnerability of an individual. There are many reasons why the elderly are more vulnerable to a disaster, including, …”physical limitations that influence their inability or unwillingness to comply with mandatory evacuation orders; post-disaster psychological stress that impairs recovery and increases the need for additional social services; declining cognitive abilities to process hazard information necessitating specially targeted risk communication or warning messages; and fewer economic resources to repair damaged 3 homes, especially by elderly residents on fixed incomes. Thus, the greater the proportion of elderly in a community, the more vulnerable it is and the longer it will take for the community to fully recover from the disaster’s aftermath” (Cutter and Finch 2008, p. 2301). o Physical vulnerability characteristics of the built environment are those local structures that are threatened by hazards. The type, number and improved value of structures that serve as community assets are indicators of vulnerability. As illustrated in Figures 1a, 1b, and 1c, vulnerability can be described as the extent to which social vulnerability and physical vulnerability overlap hazard exposure (areas A, B, and C). A reduction in vulnerability is represented by smaller overlaps that with the area exposed to hazards. The aim of local planning and actions should be to reduce the overlap as illustrated in Figure 1b. The framework to guide our study of vulnerability is based on the concept of community resiliency. Resilience is “the ability to prepare and plan for, absorb, recover from, and more successfully adapt to adverse events” (NRC 2012, p. 1). Resiliency emphasizes a proactive approach to managing coastal hazards, rather than the more dominant reactive approach. Figure 2: Community Hazard Vulnerability 4 Appendix A: Methodology Three major tasks were undertaken to achieve the study objectives: 1) delineate hazard zones; 2) estimate vulnerability based on geospatial indicators; and 3) mapping vulnerability scores. Task 1: Delineate Hazard Zones Initially, we focused on delineation of hazard zones based on the National Flood Insurance Program (NFIP) flood maps and sea level rise. While there are other coastal hazards (shoreline erosion, historical hurricane events, precipitation driven stormwater floods), we focused on NFIP flood zones given their salience in national policy and nationwide availability of data linked to these hazards. Delineation of NFIP flood hazard zones is based on the probability of experiencing a flood as defined by the Digital Flood Insurance Rate Map (DFIRM) 100-year (1% occurrence probability per year) floodplain boundaries. The 100-year floodplains are widely used in local hazard mitigation policy formulation to administer and enforce federal policy goals under the NFIP. Next, we delineated areas exposed to sea level rise. Recent advances in down-scaling the effects of global climate change on sea level rise have made it possible to make such delineations (Climate Central 2014). We use the widely applicable data derived from the U.S. Army Corps of Engineer’s (USACE) “Sea Level Rise Calculator” that provides alternative scenarios in 10-year increments up 2100 for relative local sea level rise along the U.S. coast (USACE 2014).1 The data from USACE provides five potential sea level rise scenarios recorded by the National Oceanic and Atmospheric Administration (NOAA) tide gauges: low, intermediate low, intermediate, intermediate high and high sea level change projections. The Sea Level Rise Calculator provides relative sea level change projections in ten year increment using the five different scenarios and was used to project possible scenarios. For this research, the intermediate high scenario (6-foot rise by in 2100, relative to 2014) projected by NOAA for the Galveston area is utilized. In order to delineate the temporal and spatial sea level changes on the map, we use the USGS digital elevation model (DEM) data (source: The Houston-Galveston Area Council), to forecast sea level rise contained within a 6-foot elevation change relative to existing sea level conditions. Task 2: Estimate Vulnerability Based on Geospatial Indicators The next task was to identify geospatial indicators of physical and social vulnerability. Building tax values for 2010 are used as a straightforward measure of physical Sea level rise experienced by an observer on land is referred to as "relative" sea level rise. “Relative” sea level rise is a function of changes in eustatic sea level as well as shifts in the elevation of the land. Eustatic sea level rise is the increase in the volume of the oceans that results primarily from the thermal expansion of sea water as heat is transferred from the atmosphere and from the melting of glaciers, ice caps, and the Greenland and West Antarctic ice sheets. Relative sea level rise is eustatic sea level adjusted for the local rate of vertical land movement. 1 5 vulnerability and can be readily converted to a standardized measure (e.g., U.S.$/square foot).2 Social vulnerability was measured using variables from the Social Vulnerability for Disaster Management project developed by the U.S. Centers for Disease Control (CDC) using data from the 2010 U.S. Census at the census tract and block group level (Flanagan et al. 2011). The project involved organizing social vulnerability into four domains – socioeconomic status, household composition, minority status, and housing/transportation – represented by 15 demographic variables selected based on evidence derived from a comprehensive review of the hazards vulnerability literature. However, 12 indicators were used since the 2010 Census did not include data for three indicators (see Table A1). Table A1: US Census 2010 Variable Definitions* Domain Socioeconomic Status Household Composition Minority Status Variable 2010 Census Table Variable(s) Censu s Level Description Percent individuals below poverty T117 Block Group Individuals below poverty=”under .50” +“.50 to .74” + “.75 to .99.” Percent of persons below federally defined poverty line, a threshold that varies by the size and age composition of the household. Denominator is total population where poverty status is checked. Per capita income in 2010 T83 Block Group Mean income computed for every person in census block group. (In <DollarYear> inflation adjusted dollars) Percent persons with less than high school diploma T25 Block Group Percent of persons 25 years of age and older, with less than a 12th grade education (including individuals with 12 grades but no diploma). Percent persons 65 years of age or older T7 Block Group Percent persons 17 years of age or younger T7 Block Group B09002 Block Group “Other family: male householder, no wife present, with own children under 18 years” + “Other family: female householder, no husband present, with own children under 18 years Block Group Total of the following: “black or African American alone” + “American Indian and Alaska Native alone” + “Asian alone” + “Native Hawaiian and other Pacific Islander alone” + “some other race alone” + “two or more races” + “Hispanic or Latino white alone.” Percent male or female householder, no spouse present, with children under 18 Percent Minority T13 2 Data Source: Harris County Appraisal District (HCAD) Real & Personal Property Database: http://pdata.hcad.org/download/ 6 Percent persons 5 years of age or older who speak English less than “well” Housing / Transportation B16004 Block Group For all age groups and all languages - the total of persons who speak English “not well” or “not at all.” Percent multi-unit structure T97 Block Group Percent housing units with 10 or more units in structure. Percent mobile homes T97 Block Group Percent housing units that are mobile homes. Crowding B25014 Block Group At household level, more people than rooms. Percent total occupied housing units (i.e., households) with more than one person per room. No vehicle available B25044 Block Group Percent households with no vehicle Available. * The Flanagan et al. (2011) model used 15 variables. However, 3 variables were excluded (percent persons more than 5 years old with a disability, percent persons in group quarters, percent unemployed) because the 2010 Census did not include this data. Source: ACS 2006-2010 (5 Year Estimates) Each social indicator, except for per capita income, was ranked from highest to lowest across all census block groups in Houston (N = 1,451). Per capita income was ranked from lowest to highest since, unlike the other indicators, a higher value means lesser vulnerability. A percentile rank was then calculated for each block group for each of the indicators.3 To identify the most vulnerable population for each indicator we identified block groups with percentile ranks of 25 or higher. These block groups were then identified and illustrated on a set of maps (see Appendix B). Task 3: Mapping Vulnerability The next stage of the process involves mapping the distribution of the physical vulnerability (i.e., building tax value scores) and most socially vulnerable populations in hazard zones of land policy districts. Both sets of indicators were originally represented in a GIS as vector polygons. Such polygons contain large uncertainty in how the percentile rank values of social vulnerability and physical vulnerability (i.e., building tax values) are distributed inside each individual census block (population) or parcel (building tax). Vector representation is problematic when only a portion of a polygons intersect a boundary of a hazard zone within each land policy district, because it is not possible to discern the physical vulnerability and percentile rank values that are located inside the hazard areas of land policy districts. 3 A percentile rank is defined at the proportion of scores in a distribution that a specific score is greater than or equal to. Percentile ranks were calculated by using the formula: Percentile Rank = (Rank-1) / (N-1) Where N = the total number of data points, and all sequences of ties are assigned the smallest of the corresponding ranks. 7 This spatial distribution problem was addressed for each type of vulnerability. For social vulnerability, LandScan data was used to distribute the percentile rank vulnerability values at a finer resolution than the Census block groups. LandScan is a national population distribution model developed at Oak Ridge National Laboratory (ORNL 2013) that that estimates the number of people within 90-meter cells for both residential and daytime populations to a higher degree of accuracy compared to other population distribution models (Patterson and Doyle 2010, Sabesan et al. 2007).4 Using LandScan data, each block group polygon was divided into 90-meter cells (see Figure 3). The percentile rank value for a given block group was then assigned to each cell. If a cell had zero population count, it was assigned a percentile rank value of zero. Figure 3: Application of LandScan Application of LandScan LandScan"(90"m"x"90m)" Census"block"group" Example:" There"18"people"in"the"2"cells" of"LandScan"data"(about" 0.006844"sq"mile)."Based"on" areal"weighted"method,"there" are"about"9.56"people"in"it." Source: U.S. Census (2010) and ORNL (2010). In order to calculate physical vulnerability, improvement values of structures for 2010 are used. The Harris County Appraisal District (HCAD) provides not only 2010 real estate and personal property value data, but also physical parcel boundary data. After sorting and organizing the data for the Sims Bayou watershed, we standardized the values by each census block group (e.g., U.S.$/square foot). Additionally, the hazard zones (100year floodplain and 2100 sea level rise boundaries) in Sims Bayou watershed are overlaid on each parcel and the standardized improved parcel value of each block group in the hazard zones are calculated. Based on the standardized value for each block group, we classify the values into three categories with an equal number of units in each category (e.g., low, medium and high standardized values) and map the scores. 4 For this study nighttime population estimates were used since this data represents the distribution of the residential population. 8 Table of Contents: Appendix B Appendix B includes three sets of findings derived from the social vulnerability analysis. 1. Tables B1, B2, and B3 include summary statistics for each of 12 social vulnerability indicators. The statistics compare the percent and number of people who are social vulnerable at different geographic scales. Table B1 displays the percent and number of people that live in the 100year floodplain by indicator in Sims Bayou and compares these findings to the entire Sims Bayou watershed and the City of Houston. Table B2 displays the percent and number of people by indicator who live in the area projected to be exposed to sea level rise in 2100 and compares these findings to the entire Sims Bayou watershed and the City of Houston. Table B3 compares the percent and number of people that live in the 100-year floodplain with the percent and number of people exposed to the potential sea level rise in 2100 by indicator. 2. Figures B1-B12 displays mapped findings of the most socially vulnerable populations within Sims Bayou for each of the 12 social vulnerability indicators listed in Tables B1-B3. As discussed in Appendix A, the most vulnerable are considered to be in the top 25 percent of census blocks among over 1,451 census blocks in Houston. We identified these areas and displayed them on maps in the Sims Bayou watershed. 3. Table B-4 and Figure B13 illustrate physical vulnerability based on the improved value of structures within the Sims Bayou watershed. 9 List of Tables and Figures: Appendix B Summary Statistics for Social Vulnerability Table B1. Social Indicators within 100-year floodplain, Sims Bayou Watershed & Houston Table B2. Social Indicators within 2100 sea level rise, Sims Bayou Watershed & Houston Table B3. Social Indicators within 100-year floodplain, 2100 sea level rise & Remainder of the watershed Maps of Social Vulnerability Figure B1. Social Indicator Poverty inside the 100-year Floodplain and Remainder of the Watershed Figure B2. Social Indicator Per capita Income inside the 100-year Floodplain and Remainder of the Watershed Figure B3. Social Indicator Less than High School inside the 100-year Floodplain and Remainder of the Watershed Figure B4. Social Indicator Older than 65 inside the 100-year Floodplain and Remainder of the Watershed Figure B5. Social Indicator Younger than 17 inside the 100-year Floodplain and Remainder of the Watershed Figure B6. Social Indicator Single Parent Household inside the 100-year Floodplain and Remainder of the Watershed Figure B7. Social Indicator Minority inside the 100-year Floodplain and Remainder of the Watershed Figure B8. Social Indicator English Fluency inside the 100-year Floodplain and Remainder of the Watershed Figure B9. Social Indicator Multi-unit Structures inside the 100-year Floodplain and Remainder of the Watershed Figure B10. Social Indicator Mobile Homes Inside the 100-year Floodplain and Remainder of the Watershed Figure B11. Social Indicator Crowding inside the 100-year Floodplain and Remainder of the Watershed Figure B12. Social Indicator No Vehicle inside the 100-year Floodplain and Remainder of the Watershed Summary Statistics and Map of Physical Vulnerability Table B4. Physical Indicators within the Hazard Zones and the Watershed Figure B13. Standardized Improved Parcel Value within Sims Bayou Watershed (US$/square foot) Figure B14. Standardized Improved Parcel Value within 100-year floodplain (US$/square foot) Figure B15. Standardized Improved Parcel Value within 2100 sea level rise (US$/square foot) 10 Table B1: Social Indicators within 100-year floodplain, Sims Bayou Watershed & Houston Socioeconomic Status Social Indicator Data Level Below Poverty Population Per Capita Income ($) 100-year Floodplain (number) Sims Bayou Watershed (number) Houston (number) 8.5% (2,227) 8.9% (27,161) 8.5% (169,863) $ 14,207 $ 15,007 $ 26,102 Less than High School Population 23.1% (6,054) 21.7% (66,058) 16.5% (330,900) Older than 65 Population 8.6% (2,241) 8.5% (25,962) 9.1% (181,085) Younger than 17 Population 31.7% (8,311) 30.6% (93,002) 26.1% (522,082) Family with One Spouse Households with Children 34.6% (2,435) 38.9% (29,570) 36.8% (165,279) Minority Population 46.3% (12,131) 58.0% (176,485) 44.6% (891,025) English Less than Well Population 19.3% (5,054) 18.1% (55,147) 14.3% (286,563) Multi-Unit Housing Housing Units 17.9% (1,593) 20.6% (22,224) 34.6% (298,190) Mobile Homes Housing Units 1.9% (173) 2.8% (3,019) 1.4% (12,457) Crowding (people/room) Housing Units 10.0% (896) 8.8% (9,523) 6.3% (54,582) No Vehicle Available Housing Units 9.6% (857) 9.3% (10,028) 8.7% (75,341) Total Population 26,180 304,062 1,999,431 Area (sq. mi) 7.1 (8.4%) 84.9 (100%) 587.8 Overall Population Density (per sq. mi) 3,687 3,581 3,402 Household Composition Minority Status Housing / Transportation 11 Table B2. Social Indicators within 2100 sea level rise, Sims Bayou Watershed & Houston Socioeconomic Status Social Indicator Data Level Below Poverty Population Per Capita Income ($) 2100 Sea Level Rise* (number) Sims Bayou Watershed (number) Houston (number) 4.9% (3,341) 8.9% (27,161) 8.5% (169,863) $ 14,529 $ 15,007 $ 26,102 Less than High School Population 11.9% (8,162) 21.7% (66,058) 16.5% (330,900) Older than 65 Population 4.2% (2,861) 8.5% (25,962) 9.1% (181,085) Younger than 17 Population 16.3% (11,130) 30.6% (93,002) 26.1% (522,082) Family with One Spouse Households with Children 31.0% (3,048) 38.9% (29,570) 36.8% (165,279) Minority Population 23.2% (15,845) 58.0% (176,485) 44.6% (891,025) English Less than Well Population 11.2% (7,646) 18.1% (55,147) 14.3% (286,563) Multi-Unit Housing Housing Units 9.3% (2,365) 20.6% (22,224) 34.6% (298,190) Mobile Homes Housing Units 1.3% (319) 2.8% (3,019) 1.4% (12,457) Crowding (people/room) Housing Units 5.6% (1,422) 8.8% (9,523) 6.3% (54,582) No Vehicle Available Housing Units 4.2% (1,077) 9.3% (10,028) 8.7% (75,341) Total Population 26,180 304,062 1,999,431 Area (sq. mi) 7.1 (8.4%) 84.9 (100%) 587.8 Overall Population Density (per sq. mi) 3,687 3,581 3,402 Household Composition Minority Status Housing / Transportation * Excludes 100-year floodplain 12 Table B3. Social Indicators within 100-year floodplain, 2100 sea level rise & Remainder of the Watershed Socioeconomic Status Social Indicator Data Level Below Poverty Population Per Capita Income ($) 100-year Floodplain (number) 2100 Sea Level Rise* (number) Remainder (number) 8.5% (2,227) 4.9% (3,341) 8.9% (21,593) $ 14,207 $ 14,529 $ 15,267 Less than High School Population 23.1% (6,054) 11.9% (8,162) 21.4% (51,843) Older than 65 Population 8.6% (2,241) 4.2% (2,861) 8.6% (20,860) Younger than 17 Population 31.7% (8,311) 16.3% (11,130) 30.3% (73,560) Family with One Spouse Households with Children 34.6% (2,435) 31.0% (3,048) 9.9% (24,087) Minority Population 46.3% (12,131) 23.2% (15,845) 61.2% (148,509) English Less than Well Population 19.3% (5,054) 11.2% (7,646) 17.5% (42,447) Multi-Unit Housing Housing Units 17.9% (1,593) 9.3% (2,365) 7.5% (18,266) Mobile Homes Housing Units 1.9% (173) 1.3% (319) 1.0% (2,527) Crowding (people/room) Housing Units 10.0% (896) 5.6% (1,422) 3.0% (7,205) No Vehicle Available Housing Units 9.6% (857) 4.2% (1,077) 3.3% (8,094) Total Population 26,180 26,180 242,528 Area (sq. mi) 7.1 (8.4%) 7.1 (8.4%) 70.1 (82.5%) Overall Population Density (per sq. mi) 3,687 3,687 3,460 Household Composition Minority Status Housing / Transportation * Excludes 100-year floodplain 13 Maps of Social Vulnerability Figure B1. Social Indicator Poverty inside the 100-year Floodplain and Remainder of the Watershed Figure B2. Social Indicator Per capita Income inside the 100-year Floodplain and Remainder of the Watershed 14 Figure B3. Social Indicator Less than High School inside the 100-year Floodplain and Remainder of the Watershed Figure B4. Social Indicator Older than 65 inside the 100-year Floodplain and Remainder of the Watershed 15 Figure B5. Social Indicator Younger than 17 inside the 100-year Floodplain and Remainder of the Watershed Figure B6. Social Indicator Single Parent Household inside the 100-year Floodplain and Remainder of the Watershed 16 Figure B7. Social Indicator Minority inside the 100-year Floodplain and Remainder of the Watershed Figure B8. Social Indicator English Fluency inside the 100-year Floodplain and Remainder of the Watershed 17 Figure B9. Social Indicator Multi-unit Structures inside the 100-year Floodplain and Remainder of the Watershed Figure B10. Social Indicator Mobile Homes Inside the 100-year Floodplain and Remainder of the Watershed 18 Figure B11. Social Indicator Crowding inside the 100-year Floodplain and Remainder of the Watershed Figure B12. Social Indicator No Vehicle inside the 100-year Floodplain and Remainder of the Watershed 19 Summary Statistics and Map of Physical Vulnerability Table B4. Physical Indicators within the Hazard Zones and the Watershed Physical Indicator Total Improved Value Standardized Improved Value (by sq. ft) 100-year Floodplain (%) $ 749 Million (12.5%) $4.6 2100 SLR: 6-foot* (%) $ 266 Million (4.4%) $1.4 Remainder of the Watershed** (%) $ 4.99 Billion (83.1%) $2.9 * Excludes 100-year floodplain ** Excludes 100-year floodplain and 2100 sea level rise Figure B13. Standardized Improved Parcel Value within Sims Bayou Watershed By Census Tract (US$/square foot) 20 Figure B14. Standardized Improved Parcel Value within 100-year floodplain (US$/square foot) Figure B15. Standardized Improved Parcel Value within 2100 sea level rise* (US$/square foot) * Excludes 100-year floodplain 21 References Climate Central. 2014. North Carolina and the Surging Sea: A Vulnerability Assessment with Projections for Sea Level Rise and Coastal Flood Risk. Princeton, NJ. [www.climatecentral.org] Cutter, Susan and Christina Finch. 2008. Temporal and Spatial Changes in Social Vulnerability to Natural Hazards. Proceedings of the National Academy of Sciences 105(7): 2301-2306. Flanagan, B., E. Gregory, E. Hallisey, J. Heitgerd, and B. Lewis. 2011. A Social Vulnerability Index for Disaster Management. Journal of Homeland Security and Emergency Management 8(1): 1-22. Harris County Appraisal District (HCAD). 2015. 2010 Certified Values Retrieved from http://pdata.hcad.org/download/2010.html. Oak Ridge National Laboratory (ORNL). 2013, ORNL LandScan, (accessed 2/14, http://web.ornl.gov/sci/landscan/index.shtml Patterson, L., Doyle, M. 2009. Assessing Effectiveness of National Flood Policy Through Spatiotemporal Monitoring of Socioeconomic Exposure. Journal of the American Water Resource Association 45: 237–252. Sabesan, A., K. Abercrombie, A.R. Ganguly, B. Bhaduri, E. Bright, and P. Coleman, 2007. Metrics for the Comparative Analysis of Geospatial Datasets With Applications to High-Resolution Grid-Based Population Data. Geo Journal 69: 81-91. US Army Corps of Engineers (USACE). 2014a. Application of Flood Risk Reduction Standard for Sandy Rebuilding Projects: Sea-Level Change Curve Calculator Using the Flood Risk Reduction Standard for Sandy Rebuilding Projects [http://www.corpsclimate.us/ccaceslcurvesECB.html] U.S. Census Bureau. 2006-2010 American Community Survey 5-year estimates. Using American FactFinder. Retrieved from http://factfinder2.census.gov. 22