Geography Commons^™

Field Measurements Of Influence Of Sand Transport Rate On Structure Of Wind-Sand Flow Over Coastal Transverse Ridge, Yuxiang Dong, S. L. Namikas, P. A. Hesp, Jun Ma

Faculty Publications

The structure of wind-sand flow under different total sand transport rates was measured with field vertical anemometer and sand trap on the crest of typical coastal transverse ridge in Changli Gold Coast of Hebei Province, which is one of the most typical coastal aeolian distribution regions in China and famous for the tall and typical coastal transverse ridges. The measurement results show that, on the conditions of approximate wind velocities and same surface materials and environments, some changes happen to the structure of wind-sand flow with the increase of total sand transport rate on the crest of coastal transverse ridge. …

Significance Of Altitude And Posting Density On Lidar-Derived Elevation Accuracy On Hazardous Waste Sites, María J. García-Quijano, John R. Jensen, Michael E. Hodgson, Brian C. Hadley, John B. Gladden, Lewis A. Lapine

Faculty Publications

This research evaluated the vertical accuracy of two lidar-derived elevation datasets acquired from two different altitudes over a clay-capped hazardous waste site located on the Savannah River Site (SRS), South Carolina, using the same Optech ALTM 2050 lidar sensor and Cessna 337 platform. Both missions provided adequate elevation estimates (low-altitude RMSEz ≈ 6 cm; high-altitude RMSEz ≈ 14 cm.) A quantitative comparison was performed to determine how decreasing platform altitude and increasing lidar posting density affected the vertical elevation accuracy. Higher posting densities did not significantly improve the vertical accuracy of lidar-derived elevation data. Conversely, acquiring the lidar-derived elevation data …

Gis Aided Archaeological Research Of El Camino Real De Los Tejas With Focus On The Landscape And River Crossings Along El Camino Carretera., Jeffrey M. Williams

Faculty Publications

Many generations of indigenous pathways through the forests of eastern Texas have their origins obscured in antiquity. Utilized by early European explorers, these pathways became modified through heavy use and the expansions and improvements needed to accommodate easy passage of European horses and carts and finally the heavy wagons of Anglo-American settlers. The first road through Texas, El Camino Real de Los Tejas, utilized portions of these early trails.

El Camino Carretera (known as the cart road) is an early segment of El Camino Real de los Tejas that crossed the Sabine River at the boundary between Texas and Louisiana. …

A Potential Pollen Proxy For Enso Derived From The Sajama Ice Core, Kam-Biu Liu, Carl A. Reese, Lonnie G. Thompson

Faculty Publications

An annually resolved pollen record spanning a 39-year period ( 1958 - 1996) from the Sajama Ice Cap, located on the western Bolivian Altiplano, reveals significant interannual variations in both pollen concentration and composition. The pollen assemblages within the annual layers are dominated by typical Altiplano taxa, especially Poaceae and Asteraceae. On an annual basis the pollen concentrations are strongly negatively correlated (Pearson's r = - 0.716) with the Southern Oscillation Index (SOI). Studies from Sajama and other tropical ice caps have shown that during El Nino years, the weather on the Altiplano is decidedly warmer and drier, which enhances …

Merging Gps Data With High Spatial Resolution Multispectral Imagery: An Urban Recreation Case Study, Daniel Unger, David Kulhavy, Jerome E. Benson Ii

Faculty Publications

In 1992 a disc golf course was created by Alpha Phi Omega, Nu Sigma Chapter of Stephen F. Austin State University within Pecan Park in the c ity of Nacogdoches, Texas. Using constructs from Landscape Ecology, in cluding structure, function and change within a land mosaic provided the basis for establishment of the course. The addition of the disc golf cour se modified the use of the park promoting cultural cohesion among the disc golf enthusiasts. To aid the recreational enjoyment of golf participants, vector m aps of each fairway were created when the disc course was developed and loca …

Landscapes Of Power And Identity: Comparative Histories In The Sonoran Desert And The Forests Of Amazonia From Colony To Republic, Andrew Sluyter

Faculty Publications

No abstract provided.

Visual Representations Of The Spatial Relationship Between Bermuda High Strengths And Hurricane Tracks, Jason T. Knowles, Michael Leitner

Faculty Publications

The 2004 and 2005 hurricane seasons dramatically demonstrated the magnitude of the societal significance of hurricanes, negatively impacting on all scales from the personal to the national. Although definitive identification of the forcing mechanisms controlling hurricane tracks and landfall patterns remains elusive, increasing evidence supports the hypothesis that the increase in hurricane activity along the Gulf Coast is due to a southwestward shift in the position of the Bermuda High. This research uses multiple visualization techniques to explore the spatial correlation between Bermuda High strengths - as interpreted from the North Atlantic Oscillation (NAO) index - and hurricane tracks. Using …

Use Of The Global Positioning System In The Field Recovery Of Scattered Human Remains, Ginesse A. Listi, Mary H. Manhein, Michael Leitner

Faculty Publications

This study examines the Global Positioning System (GPS) as a tool for field mapping of scattered human remains or other materials in forensic investigations. Two aspects of the GPS are considered: (1) the level of accuracy that can be obtained using a mid-priced GPS unit, and (2) the effectiveness of using the GPS to map scattered materials. The positional accuracy of the GPS receiver was tested using a National Geodetic Survey (NGS) point located in Baton Rouge, LA. The utility of the GPS for mapping was investigated by setting up a mock field recovery and mapping the remains using both …

Impact Of Lidar Nominal Post-Spacing On Dem Accuracy And Flood Zone Delineation, George T. Raber, John R. Jensen, Michael E. Hodgson, Jason A. Tullis, Bruce A. Davis, Judith Berglund

Faculty Publications

Lidar data have become a major source of digital terrain information for use in many applications including hydraulic modeling and flood plane mapping. Based on established relationships between sampling intensity and error, nominal post-spacing likely contributes significantly to the error budget. Post-spacing is also a major cost factor during lidar data collection. This research presents methods for establishing a relationship between nominal post-spacing and its effects on hydraulic modeling for flood zone delineation. Lidar data collected at a low post-spacing (approximately 1 to 2 m) over a piedmont study area in North Carolina was systematically decimated to simulate datasets with …

Spatial Confidentiality And Gis: Re-Engineering Mortality Locations From Published Maps About Hurricane Katrina, Andrew J. Curtis, Jacqueline W. Mills, Michael Leitner

Faculty Publications

Background: Geographic Information System (GIS) can provide valuable insight into patterns of human activity. Online spatial display applications, such as Google Earth, can democratise this information by disseminating it to the general public. Although this is a generally positive advance for society, there is a legitimate concern involving the disclosure of confidential information through spatial display. Although guidelines exist for aggregated data, little has been written concerning the display of point level information. The concern is that a map containing points representing cases of cancer or an infectious disease, could be re-engineered back to identify an actual residence. This is …

Keeping An Eye On Privacy Issues With Geospatial Data [4], Andrew Curtis, Jacqueline W. Mills, Michael Leitner

Faculty Publications

No abstract provided.

Accuracy Assessment Of Land Cover Maps Derived From Multiple Data Sources, Daniel Unger, Hillary Tribby, Hans Michael Williams, I-Kuai Hung

Faculty Publications

Maximum Likelihood (ML) and Artificial Neural Network (ANN) supervised classification methods were used to demarcate land cover types within IKONOS and Landsat ETM+ imagery. Three additional data sources were integrated into the classification process: Canopy Height Model (CHM), Digital Terrain Model (DTM) and Thermal data. Both the CHM and DTM were derived from multiple return small footprint LIDAR. Forty maps were created and assessed for overall map accuracy, user's accuracy, producer's accuracy, kappa statistic and Z statistic using classification schemes from U.S.G.S. 1976 levels 1 and 2 and T.G.l.C. 1999 levels 2 and 4. Results for overall accuracy of land …

Spatial Analysis Of Historic Cemeteries: Using High Spatial Resolution Imagery As A Visual Aid, Richard E. Brooks, Daniel Unger, I-Kuai Hung

Faculty Publications

Oak Grove Cemetery, located within the City of Nacogdoches in Nacogdoches County Texas, is one of the earliest cemeteries in the county dating to the early 1800’s. Several historic Texans are interred within this cemetery including Thomas J. Rusk and Charles S. Taylor who was the great-great-grandfather of current United States Senator Kay Bailey Hutchison. Due to a fire circa 1910 many of the records for the original section of the cemetery were lost. In the summer of 2006, the GPS coordinates of each grave marker within the cemetery were plotted on a backdrop of 6 inch spatial resolution multispectral …

Humboldt In The Americas, Andrew Sluyter, Kent Mathewson

Faculty Publications

No abstract provided.

Traveling/Writing The Unworld With Alexander Von Humboldt., Andrew Sluyter

Faculty Publications

No abstract provided.

Coherent Structures And Aeolian Saltation, Jean Taylor Ellis

Faculty Publications

Aeolian sand transport models, widely employed by coastal scientists and managers, assume temporal and spatial homogeneity within the saltation field. This research questions that assumption by demonstrating that the saltation field is event-driven, therefore indicating that the saltation field is not temporally steady. The findings from this research may explain a portion of the conclusions from previous studies that indicated inequalities between model-estimated and field-measured aeolian sand transport. The relationship between unsteadiness in a turbulent wind field and pulses in a sand transport field was investigated on a beach near Shoalhaven Heads, New South Wales, Australia. Microphone-based saltation sensors, “miniphones,” …

Topographies Of Home And Citizenship: Arab American Activists, Lynn A. Staeheli, Caroline R. Nagel

Faculty Publications

Home and citizenship carry contradictory and ambiguous meanings for immigrants as they negotiate lives ‘here’ and ‘there’. We use the concept of topography to analyze the ways in which activists in the Arab-American community draw connections between homes in the United States and in the Middle East. In intensive interviews, we ask activists about how their understanding of home influences their activism and positioning as citizens within the United States. Activists often bring to their work conceptualizations of home and citizenship that are open, and that connect home to broader forces operating at various scales and in more than one …

Remotely Sensed Data To Map Forest Age Class By Cover Type In East Texas, Daniel Unger, I-Kuai Hung, Jeffrey M. Williams, James Kroll, Dean W. Coble, Jason Grogan

Faculty Publications

• Remote sensing in conjunction with ground truthing, can accurately quantify forest composition and age distributions in East Texas.
• Method uses standardized and readily available data available to the general public.
• Method was shown to be effective in terms of time and cost.

Big-Bodied Males Help Us Recognize That Females Have Big Pelves, Robert G. Tague

Faculty Publications

Schultz ([1949] Am. J. Phys. Anthropol. 7:401-424) presented a conundrum: among primates, sexual dimorphism of the pelvis is a developmental adjunct to dimorphism in other aspects of the body, albeit in the converse direction. Among species in which males are larger than females in body size, females are larger than males in some pelvic dimensions; species with little sexual dimorphism in nonpelvic size show little pelvic dimorphism. Obstetrical difficulty does not explain this relationship. The present study addresses this issue, evaluating the relationship between pelvic and femoral sexual dimorphism in 12 anthropoid species. The hypothesis is that species in which …

Recentism In Environmental History On Latin America, Andrew Sluyter

Faculty Publications

No abstract provided.

Is Geography Destiny?: Lessons From Latin America. And Troubled Harvest: Agronomy And Revolution In Mexico, 1880–2002, Andrew Sluyter

Faculty Publications

No abstract provided.

‘We’Re Just Like The Irish’: Narratives Of Assimilation, Belonging, And Citizenship Among Arab American Activists, Caroline R. Nagel, Lynn A. Staeheli

Faculty Publications

This paper examines narratives of assimilation and belonging as activists attempt to position Arab-Americans as citizens and full members of the American polity. In interviews with activists, the experience of the Irish as immigrants and citizens was often invoked as the paradigmatic example of how immigrants are incorporated as citizens—an example that activists promoted as one that Arabs would follow. By invoking the Irish experience, activists hope to remind Americans that immigration history is not one of effortless assimilation, but is rather characterized by systematic exclusion and marginalization. In so doing, they articulate narratives of assimilation and belonging that draw …

An Evaluation Of Lidar-Derived Elevation And Terrain Slope In Leaf-Off Conditions, Michael E. Hodgson, John Jensen, George Raber, Jason Tullis, Bruce A. Davis, Gary Thompson, Karen Schuckman

Faculty Publications

The effects of land cover and surface slope on lidar-derived elevation data were examined for a watershed in the piedmont of North Carolina. Lidar data were collected over the study area in a winter (leaf-off) overflight. Survey-grade elevation points (1,225) for six different land cover classes were used as reference points. Root mean squared error (RMSE) for land cover classes ranged from 14.5 cm to 36.1 cm. Land cover with taller canopy vegetation exhibited the largest errors. The largest mean error (36.1 cm RMSE) was in the scrub-shrub cover class. Over the small slope range (0° to 10°) in this …

Digital Facsimiles Of The Paper Issues Of The Cultural Ecology Newsletter, Andrew Sluyter

Faculty Publications

No abstract provided.

Special Issue: Native Food Production Knowledge Systems And Practices: Alternative Values And Outcomes-From The Guest Editors, Andrew Sluyter, Alfred H. Siemens

Faculty Publications

No abstract provided.

Los Orígenes Ecológicos Y Las Consecuencias De La Ganadería En La Nueva España Durante El Siglo Xvi, Andrew Sluyter

Faculty Publications

No abstract provided.

Citizenship, Identity, And Transnational Migration: Arab Immigrants To The Us, Caroline R. Nagel, Lynn A. Staeheli

Faculty Publications

The aim of this paper is to evaluate the changing relationships between identities, citizenship and the state in the context of globalisation. We first examine the ways in which scholars discuss changes in the ways in which citizenship and political identity are expressed in the context of international migration. We argue that much of the discussion of transnationalism and diaspora cling to an assumption that citizenship remains an important—though not defining—element of identity. Our position, by contrast, is that migration is one of a number of processes that transform the relationship between citizenship and identity. More specifically, we argue that …

Review Of Geography Militant: Cultures Of Exploration And Empire, By Felix Driver, Andrew Sluyter

Faculty Publications

No abstract provided.

Accuracy Of Airborne Lidar-Derived Elevation: Empirical Assessment And Error Budget, Michael E. Hodgson, Patrick Bresnahan

Faculty Publications

As part of a countywide large-scale mapping effort for Richland County, South Carolina, an accuracy assessment of a recently acquired lidar-derived data set was conducted. Airborne lidar (2-m nominal posting) was collected at a flying height of 1207 meters above ground level (AGL) using an Optech ALTM (Airborne Laser Terrain Mapper) 1210 system. Unique to this study are the reference point elevations. Rather than using an interpolation approach for gathering observed elevations at reference points, the x-y coordinates of lidar points were located in the field and these elevations were surveyed. Using both total-station-based and rapid-static GPS techniques, observed vertical …

A Parameterization Model For Transportation Feature Extraction, Michael E. Hodgson, Xingong Li, Yang Cheng

Faculty Publications

This article presents one solution to the parameterization problem for automated road feature extraction models. Using a line-length buffer approach, a measure of agreement between extracted road features and reference road features is defined. An automated approach for deriving this agreement index is presented and implemented as a parameterization model. Coupling the implemented parameterization model with an existing transportation feature extraction model is demonstrated. Although the solution was designed for a road feature extraction model (FEM), the conceptual design could be applied to other linear FEMs, such as models for streams, fault lines, and isolines.