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Results for “Annals of the Association of American Geographers”

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13 recordsLinked to original sources
USGS2013

The participatory vulnerability scoping diagram - deliberative risk ranking for community water systems

Natural hazards and climate change present growing challenges to community water system (CWS) managers, who are increasingly turning to vulnerability assessments to identify, prioritize, and adapt to risks. Effectively assessing CWS vulnerability requires information and participation from various sources, one of which is stakeholders. In this article, we present a deliberative risk-ranking methodology, the participatory vulnerability scoping diagram (P-VSD), which allows rapid assessment and integration of multiple stakeholder perspectives of vulnerability. This technique is based on methods of deliberative risk evaluation and the vulnerability scoping diagram. The goal of the methodology is to engage CWS managers and stakeholders collectively to provide qualitative contextual risk rankings as a first step in a vulnerability assessment. We conduct an initial assessment using a case study of CWS in two U.S. counties, sites with broadly similar exposures but differences in population, land use, and other social sensitivity factors. Results demonstrate that CWS managers and stakeholders in the two case study communities all share the belief that their CWS are vulnerable to hazards but differ in how this vulnerability manifests itself in terms of the exposure, sensitivity, and adaptive capacity of the system.

Annals of the Association of American Geographers↗
USGS2016

Loamy, two-storied soils on the outwash plains of southwestern lower Michigan: Pedoturbation of loess with the underlying sand

Soils on many of the outwash plains in southwestern Michigan have loamy upper profiles, despite being underlain by sand-textured outwash. The origin of this upper, loamy material has long been unknown. The purpose of this study is to analyze the spatio-textural characteristics of these loamy-textured sediments to ascertain their origin(s). The textural curves of this material have distinct bimodality, with clear silt and sand peaks. Because the sand peaks align with those in the outwash below, we conclude that the upper material is a mixture of an initially silty material with the sand from below, forming loamy textures. By applying a textural filtering operation to the data, we determined its original characteristics; nearly all of the soils originally had silt loam upper profiles, typical for loess. Field data showed that the loamy material is thickest east of a broad, north–south trending valley (the Niles-Thornapple Spillway) that once carried glacial meltwater. The material becomes thinner, generally better sorted, and finer in texture eastward, away from this channel. We conclude that the loamy mantle on many of the adjacent outwash plains is silt-rich loess, derived from the Niles-Thornapple Spillway and its tributary channels and transported on mainly westerly winds. The spillway was active between ca. 17.3 and 16.8 k cal. years ago. At this time, a large network of tunnel channels existed beneath the stagnant Saginaw lobe ice. Meltwater from the lobe funneled silt-rich sediment into the spillway, rendering it a prodigious silt source.

Michigan↗
USGS2016

Relations of alpine plant communities across environmental gradients: Multilevel versus multiscale analyses

Alpine plant communities vary, and their environmental covariates could influence their response to climate change. A single multilevel model of how alpine plant community composition is determined by hierarchical relations is compared to a separate examination of those relations at different scales. Nonmetric multidimensional scaling of species cover for plots in four regions across the Rocky Mountains created dependent variables. Climate variables are derived for the four regions from interpolated data. Plot environmental variables are measured directly and the presence of thirty-seven site characteristics is recorded and used to create additional independent variables. Multilevel and best subsets regressions are used to determine the strength of the hypothesized relations. The ordinations indicate structure in the assembly of plant communities. The multilevel analyses, although revealing significant relations, provide little explanation; of the site variables, those related to site microclimate are most important. In multiscale analyses (whole and separate regions), different variables are better explanations within the different regions. This result indicates weak environmental niche control of community composition. The weak relations of the structure in the patterns of species association to the environment indicates that either alpine vegetation represents a case of the neutral theory of biogeography being a valid explanation or that it represents disequilibrium conditions. The implications of neutral theory and disequilibrium explanations are similar: Response to climate change will be difficult to quantify above equilibrium background turnover.

Annals of the Association of American Geographers↗
USGS2018

Anthropocene landscape change and the legacy of nineteenth- and twentieth-century mining in the Fourmile Catchment, Colorado Front Range

Human impacts on earth surface processes and materials are fundamental to understanding the proposed Anthropocene epoch. This study examines the magnitude, distribution, and long-term context of nineteenth- and twentieth-century mining in the Fourmile Creek catchment, Colorado, coupling airborne LiDAR topographic analysis with historical documents and field studies of river banks exposed by 2013 flooding. Mining impacts represent the dominant Anthropocene landscape change for this basin. Mining activity, particularly placer operations, controls floodplain stratigraphy and waste rock piles related to mining cover >5% of hillslopes in the catchment. Total rates of surface disturbance on slopes from mining activities (prospecting, mining, and road building) exceed pre-nineteenth-century rates by at least fifty times. Recent flooding and the overprint of human impacts obscure the record of Holocene floodplain evolution. Stratigraphic relations indicate that the Fourmile valley floor was as much as two meters higher in the past 2,000 years and that placer reworking, lateral erosion, or minor downcutting dominated from the late Holocene to present. Concentrations of As and Au in the fine fraction of hillslope soil, mining-related deposits, and fluvial deposits serve as a geochemical marker of mining activity in the catchment; reducing As and Au values in floodplain sediment will take hundreds of years to millennia. Overall, the Fourmile Creek catchment provides a valuable example of Anthropocene landscape change for mountainous regions of the Western United States, where hillslope and floodplain markers of human activity vary, high rates of geomorphic processes affect mixing and preservation of marker deposits, and long-term impact varies by landscape location.

Colorado↗
USGS2023

Critical stakeholder engagement: The road to actionable science Is paved with scientists’ good intentions

To help stakeholders such as planners, resource managers, policymakers, and decision makers address environmental challenges in the Anthropocene, scientists are increasingly creating actionable science—science that is useful, usable, and used. Critical physical geography encourages the engagement of stakeholders in the creation of scientific knowledge to conduct actionable science and produce outputs that are directly relevant to stakeholder plans, decisions, or actions. Many scientists, however, lack formal training in how to partner with stakeholders using effective and ethical practices. In this article, we use the core principles for ethical research of respect for persons, beneficence, and justice from the Belmont Report (1979) as a suggested framework to examine the perspectives of stakeholders engaged in climate adaptation science projects. We argue that this framework aligns with the principles of critical physical geography and provides guidance for scientists to make their research more actionable while placing necessary emphasis on ethical considerations. We also challenge scientists to consider the broader ethical implications of engaging with these partners.

Annals of the American Association of Geographers↗
USGS2025

The influence of scale in modeling social vulnerability and disaster assistance

Understanding how social vulnerability relates to disaster impacts is critical for addressing social equity, yet the role of spatial scale in this relationship is often overlooked. Most studies use aggregated data, risking ecological fallacy—misinterpreting individual outcomes from group-level data. This study examines how spatial scale influences the relationship between social vulnerability and federal disaster assistance after Hurricane Harvey. Using spatial econometric models at both household and census tract levels, we assessed the strength of key vulnerability indicators in explaining disaster assistance. Results show that disability, housing tenure, household size, and income predict assistance at the household level, but their influence shifts across scales. Income and disability remain strong predictors at the tract level, whereas housing factors weaken or reverse. These findings suggest that using aggregated data to model household-level relationships between social vulnerability and disaster assistance can distort understanding of vulnerability processes, potentially leading to misinformed disaster policies and inequitable outcomes. Our findings have implications for disaster management, but the primary contribution of this study is methodological, in providing a critical evaluation of how spatial scale and data aggregation shape the statistical interpretation of social vulnerability and aid distribution.

Texas↗
USGS2026

A new inventory and conservation assessment of United States islands

To support conservation-focused research and management we developed a new 30-m resolution polygon data layer of the nonlacustrine and nonriverine islands of the United States, with associated attributes describing key physical and conservation geography characteristics. Islands were grouped into a three-tiered hierarchy of island regions (twelve), island provinces (twenty-eight), and individual islands (19,023). Islands were classified as either continental or oceanic based on their physiographic position relative to the North America continental shelf, and estuarine versus nonestuarine depending on their location within or external to estuaries. For each island we assessed the diversity of terrestrial and coastal ecosystems, the number of threatened and endangered (T&E) species listed under the Endangered Species Act, the number of T&E species critical habitats, the number of migratory bird species listed under the Migratory Bird Treaty Act, the number of Key Biodiversity Areas, and the number of and management responsibility for protected areas. We conclude that the conservation importance of islands is disproportionate to their total area as, for example, islands contain 52 percent of the T&E species yet their total area is only 2 percent of the area of the continental mainland. Similarly, of the global total of 431 World Terrestrial Ecosystems, 201 (47 percent) occur on U.S. islands compared with 286 (66 percent) that occur on the U.S. continental mainland.

Annals of the American Association of Geographers↗
USGS2010

Comment in reply

No abstract available.

Annals of the Association of American Geographers↗
USGS2010

Natural hazards in mountain Colorado

Interdisciplinary field studies and remote sensing techniques were used to delineate mountain areas in Colorado subject to such natural hazards as snow avalanches, mudflows, rockfalls, and landslides. The old mining townsite of Ophir in the northwestern San Juan Mountains was used as a case study. Its serious snow avalanche hazard has been made even more critical with prospects of new housing developments. Techniques in remote sensing and geoecology have been applied to the solution of practical land management problems at the county and township levels of local government. The rapidly increasing hazard to human life and property results directly from accelerated growth of the winter recreation industry and construction of mountain homes. Many of the world's temperate zone high mountains urgently need development and application of new land management policies.

Colorado↗
USGS2010

The transverse and oblique cylindrical equal-area projection of the ellipsoid.

The formulas for the ellipsoidal projection are derived for both forward and inverse computations and consist of modifying the formulas obtained by using the authalic sphere so that the scale along the central line of the projection is constant. Fourier series are used to eliminate recurring numerical integration and other lengthy trigonometric computations of co-ordinates.-from Author

Annals of the Association of American Geographers↗