Ronald R. Hagelman

Visualizing Demographic Trajectories with Self-Organizing Maps

In recent years, the proliferation of multi-temporal census data products and the increased capabilities of geospatial analysis and visualization techniques have encouraged longitudinal analyses of socioeconomic census data. Traditional cartographic methods for illustrating socioeconomic change tend to rely either on comparison of multiple temporal snapshots or on explicit representation of the magnitude of change occurring between different time periods. This paper proposes to add another perspective to the visualization of temporal change, by linking multi-temporal observations to a geometric configuration that is not based on geographic space, but on a spatialized representation of n-dimensional attribute space. The presented methodology aims at providing a cognitively plausible representation of changes occurring inside census areas by representing their attribute space trajectories as line features traversing a two-dimensional display space. First, the self-organizing map (SOM) method is used to transform n-dimensional data such that the resulting two-dimensional configuration can be represented with standard GIS data structures. Then, individual census observations are mapped onto the neural network and linked as temporal vertices to represent attribute space trajectories as directed graphs. This method is demonstrated for a data set containing 254 counties and 32 demographic variables. Various transformations and visual results are presented and discussed in the paper, from the visualization of individual component planes and trajectory clusters to the mapping of different attributes onto temporal trajectories.

ENVIRONMENTAL EQUITY IN URBAN TEXAS: RACE, INCOME, AND PATTERNS OF ACUTE AND CHRONIC TOXIC AIR RELEASES IN METROPOLITAN COUNTIES

The distribution of toxic air releases in urban Texas counties is compared to socioeconomic patterns to identify inequitable risk burdens. Chronic and acute toxic airborne release patterns from 1987 to 1990 are compared to demographics for Metropolitan Area (MA) counties. Spearman rank correlation tests indicate that counties with higher percentages of Blacks and other minority groups are more likely to have higher numbers of acute and chronic toxic releases. Mann-Whitney U-tests were used to compare the race and per capita income ranks of the top and bottom 10 counties, which indicated that Blacks and other minority groups were more likely to be associated with airborne toxics. Further analyses explored these relationships at the census-tract level for three sample counties representing distinctly different proportions of Black population. Only one of the sample counties provides supportive evidence that Blacks and other non-Hispanic minorities are inequitably burdened by airborne toxic risk from toxic f...

Attribute space visualization of demographic change

This paper introduces an approach for closer integration of self-organizing maps into the visualization of spatio-temporal phenomena in GIS. It is proposed to provide a more explicit representation of changes occurring inside socio-economic units by representing their attribute space trajectories as line features traversing a two-dimensional display space. A self-organizing map consisting of several thousand neurons is first used to create a high-resolution representation of attribute space in two dimensions. Then, multi-year observations are mapped onto the neural network and linked to form trajectories. This method is implemented for a data set containing 254 counties and 34 demographic variables. Various visual results are presented and discussed in the paper, from the visualizations of individual component planes to the mapping of voting behavior onto temporal trajectories.

Disaster reconstruction and business geography following the 2007 Greensburg, Kansas Tornado

In May 2007, a tornado (classified as EF-5 on the Enhanced Fujita scale) touched down in the small Midwestern town of Greensburg, Kansas. Eleven people lost their lives, 95 per cent of the urbanized landscape was destroyed and hundreds of residents were left temporarily homeless. The towns decision to rebuild as a ‘green city’, and the many implications of that approach, has been well documented in the popular media. However, geographic change, derivative of the overall reconstruction process, has not received the same attention in ether popular or scholarly literature. Previous research on disaster reconstruction in developed cities indicates two tendencies: an areal expansion of urbanized landscapes related to structural rebuilding and an acceleration of pre-disaster development patterns, particularly within the urbanized area. Previous research has also focused on recovery among businesses in disaster reconstruction scenarios as a surrogate measure of a communitys overall return to pre-disaster conditions. Following on this line of inquiry, the purpose of this research is to analyse changes occurring in urban morphology, business locations and business types within Greensburg, KS during the first three years of reconstruction. Analysis of satellite imagery illuminates the changes in the urban morphology of the town. Analysis of economic data, captured the day of the tornado event and three years after the tornado event, illustrate the operational and locational resiliency of Greensburg businesses. Overall, there has been an expansion of Greenburgs urban footprint, a high percentage of resilient businesses choosing new locations, a slight reduction in the number of businesses overall, and changes in the type of businesses during this period of reconstruction.

People's risk perception of glacial lake outburst flooding: a case of Tsho Rolpa Lake, Nepal

Previous research indicates that peoples perception of risk from a particular hazard positively influences their adoption of effective mitigation strategies and responses. This research investigates the risk perceptions of people living downstream from Tsho Rolpa Glacial Lake of Nepal. Field surveys revealed that people living beneath the Tsho Rolpa glacial lake possess a low risk perception despite the probability of a glacial lake outburst at their location. Further investigation reveals that many individuals have made no adjustments in response to the potential disaster. The low risk perception on the part of the riverine population is chiefly attributed to the cry-wolf effect of the 1997 evacuation that followed an inaccurate prediction of a Tsho Rolpa outburst. Previous remediation structures were kept in place, but appear to have created a false sense of security among those at risk. This overconfidence in the rudimentary efforts employed thus far is illustrated by the fact that many residents have moved their infrastructure even closer to the river channel in recent years. Partial mitigation efforts have muted peoples perceptions of the environmental risk and have therefore increased the vulnerability of the communities to a probable outburst flood.

Assessing Neolocalism in Microbreweries

ABSTRACT Neolocalism can be defined as a conscious effort by businesses to foster a sense of place based on attributes of their community. Substantial research exists defining neolocalism and how businesses engage with it. Microbreweries are important actors in this movement and provide an ideal test case to develop an assessment tool. This project developed an assessment tool, using three key indicators of neolocalism, and tested its efficacy using data from microbreweries in Colorado, Oregon, and Texas. To develop the tool, three primary indicators of neolocal business practice were identified from existing literature: (1) use of local names and images in labeling and marketing; (2) environmental sustainability; and (3) social and community engagement. These indicators are important both to consumers and businesses in efforts to create a sense of place and engage with their community. Using these three indicators, more specific factors were developed to further define the index. The data are based on Internet research of microbreweries in Colorado, Oregon, and Texas using data available from the Brewers Association. Although many Web sites did not provide information related to the rubric, there were sufficient data to test the efficacy of the tool to measure neolocalism as practiced by microbreweries in these states.

Hurricane Katrina as a Lens for Assessing Socio-Spatial Change in New Orleans

Disasters are acute events that affect populated landscapes at discrete points in their history. In many locations, these discrete events occur repeatedly over time. This chronology has chorological implications in that one generations disaster reconstruction zone could be the next generations disaster site. This build-disaster-rebuild approach also occurs within the context of changing social and environmental conditions, the interactions of which have direct implications to the outcome of a specific disaster event. This research focuses on the changing social geography of a large urban disaster site (New Orleans, Louisiana) by employing the U.S. Census, digital inundation data, and a GIS to conduct a spatial analysis of flood patterns during Hurricane Katrina. Following the initial analysis, we replicate our methodology across the three decennial census periods prior to 2000. While the initial analysis discerns the statistical relationship among race, income, and Katrinas deluge, the subsequent temporal analysis illuminates the changing social patterns that preceded the Katrina-era landscape. In this manner, we use hurricane inundation as a lens to view 35 years of socio-spatial change in New Orleans.

Estimating Residential Carbon Footprints for an American City

The proliferation of online emission calculators and the growing popularity of carbon footprint assessments recently underscores an emerging interest among Americans in understanding their personal environmental impacts, especially in relation to greenhouse gas emissions. While studies have quantified carbon footprints at a variety of geographic scales using economic data, or a combination of economic and census data, few have produced results that were immediately useful for local-scale emission reduction efforts. The authors explore the feasibility of utilizing block group level census data to estimate the residential carbon footprint of an American city. A census-based emission model was adapted from the United States Environmental Protection Agencys Individual Emission Calculator. Block group census data were used as surrogates for household energy consumption and transportation related carbon emissions. Although lacking some of the finer nuances of individual behavior assessments, this approach enables analysis of a continuous urban landscape with a relatively high degree of data resolution using Geographic Information Systems GIS and standard desktop-software. The model output, paired with choropleth and dasymetric visualizations, illustrate that census data can be successfully adapted to estimate the residential carbon footprint for Austin, Texas, and by extension, any other American city with equivalent census data coverage.

Spatial and Temporal Patterns Associated with Permitted Tree Removal in Austin, Texas, 2002–2011

A wide-ranging set of physical, urban, demographic, socioeconomic, and policy characteristics determines the spatial distribution of urban forests. Information on the characteristics surrounding tree removals on both public and private properties has received less attention in the literature. The purpose of this research was to analyze the spatiotemporal trends and geographic patterns of tree removals in Austin, Texas, between 2002 and 2011 in an effort to understand how site-specific characteristics influence urban tree removal and affect the overall distribution of Austins urban forest. We examined permitted tree removals using a geographic information system (GIS) as well as spatial and statistical analyses. Specifically, we evaluated the degree to which variables related to various physical, urban, and socioeconomic conditions predicted tree removals. The results indicate that permitted tree removals and their associated characteristics in Austin have varied over the ten-year study period. Permitted tree removals increased over the study period and took place in the urban core and along the urban periphery. Permitted tree removals were more likely to be undertaken by college graduates and owner-occupants and to occur in more densely populated areas, closer to major streets, and on properties with older structures. The results of this research provide urban forest professionals with information on the location and intensity of permitted tree removals and the significant characteristics driving urban tree loss.

Resilient Landscapes: The Reconstruction of Southeastern Connecticut Following the 1938 Hurricane

Following the 1938 hurricane that damaged much of the New England coast, New London, Connecticut, responded like most communities by leveraging federal and state funds to rebuild and augment engineered mitigation structures. Eighty years of subsequent storm experience, however, illustrates that a small number of nonstructural mitigation projects, especially private property acquisitions, have had significant long-term effects on New Londons coastal resiliency, especially in the Ocean Beach neighborhood. Archival research identifies that these nonstructural mitigation projects were not initially intended to reduce hurricane or flooding risk but were aimed at removing structures determined to be public nuisances and reducing fire hazard. Therefore, New Londons post-1938 mitigation experience underscores how community-scale mitigation planning following one disaster can greatly affect the outcome of future disasters. Analytically, New Londons experience offers a compelling case study to critically compare two competing environmental mitigation approaches following the same disaster and to offer insight into the environmental legacies of both.