Scholarly Works, Geography

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Spatial Trends in the Texture, Moisture Content, and pH of a Virginia Coastal Plain Soil
Zacharias, Sebastian; Cheryl B. Heatwole; Campbell, James B. Jr. (American Society of Agricultural and Biological Engineers, 1997)
Soil texture, moisture content, and pH data from an agricultural field area of 48 _ 32 m in a Suffolk sandy loam soil in the Virginia Coastal Plain was examined for spatial trends. Trend surface analysis of sand, silt, and clay content data (n = 35) found that 68%, 74%, and 31% of the total variability in sand, silt, and clay content, respectively, was explained by second-order trend surfaces. Soil moisture content and pH also exhibited spatial trends, which resulted in statistically significant differences between subsurface moisture content and pH in two 18 _ 27 m subplots within the study area. Both moisture content and pH trends had some similarity to the trend for clay content. The spatial trends in these soil properties, however, did not translate directly into spatial trends in depth to center of bromide mass, indicating the influence of other factors in the variability of chemical distribution in the soil.
Pollen Evidence of the Prehistoric Presence of Cattail (Typha: Typhaceae) in Palo Verde National Park, Costa Rica
Horn, Sally P.; Kennedy, Lisa M. (Museo Nacional De Costa Rica, 2006)
Epistemological Pluralism: Reorganizing Interdisciplinary Research
Miller, Thaddeus R.; Baird, Timothy D.; Littlefield, Caitlin M.; Kofinas, Gary; Chapin, F. Stuart III; Redman, Charles L. (The Resilience Alliance, 2008)
Despite progress in interdisciplinary research, difficulties remain. In this paper, we argue that scholars, educators, and practitioners need to critically rethink the ways in which interdisciplinary research and training are conducted. We present epistemological pluralism as an approach for conducting innovative, collaborative research and study. Epistemological pluralism recognizes that, in any given research context, there may be several valuable ways of knowing, and that accommodating this plurality can lead to more successful integrated study. This approach is particularly useful in the study and management of social–ecological systems. Through resilience theory's adaptive cycle, we demonstrate how a focus on epistemological pluralism can facilitate the reorganization of interdisciplinary research and avoid the build-up of significant, but insufficiently integrative, disciplinary-dominated research. Finally, using two case studies—urban ecology and social–ecological research in Alaska—we highlight how interdisciplinary work is impeded when divergent epistemologies are not recognized and valued, and that by incorporating a pluralistic framework, these issues can be better explored, resulting in more integrated understanding.
Introduction to SANREM Cross Cutting Research Activities
Moore, Keith M.; Motavalli, Peter P.; Christie, Maria Elisa; Garrett, Karen A.; Heatwole, Conrad D.; Mwangi, Esther (Office of International Research, Education and Development, Virginia Tech, 2009)
The role of age, ethnicity and environmental factors in modulating malaria risk in Rajasthali, Bangladesh
Haque, Ubydul; Soares Magalhães, Ricardo J.; Mitra, Dipak; Kolivras, Korine N.; Schmidt, Wolf-Peter; Haque, Rashidul; Glass, Gregory E. (2011-12-15)
Background Malaria is endemic in the Rajasthali region of the Chittagong Hill Tracts in Bangladesh and the Rajasthali region is the most endemic area of Bangladesh. Quantifying the role of environmental and socio-economic factors in the local spatial patterns of malaria endemicity can contribute to successful malaria control and elimination. This study aimed to investigate the role of environmental factors on malaria risk in Rajasthali and to quantify the geographical clustering in malaria risk unaccounted by these factors. Method A total of 4,200 (78.9%; N = 5,322) households were targeted in Rajasthali in July, 2009, and 1,400 individuals were screened using a rapid diagnostic test (Falci-vax). These data were linked to environmental and socio-economic data in a geographical information system. To describe the association between environmental factors and malaria risk, a generalized linear mixed model approach was utilized. The study investigated the role of environmental factors on malaria risk by calculating their population-attributable fractions (PAF), and used residual semivariograms to quantify the geographical clustering in malaria risk unaccounted by these factors. Results Overall malaria prevalence was 11.7%. Out of 5,322 households, 44.12% households were living in areas with malaria prevalence of ≥ 10%. The results from statistical analysis showed that age, ethnicity, proximity to forest, household density, and elevation were significantly and positively correlated with the malaria risk and PAF estimation. The highest PAF of malaria prevalence was 47.7% for third tertile (n = 467) of forest cover, 17.6% for second tertile (n = 467) of forest cover and 19.9% for household density >1,000. Conclusion Targeting of malaria health interventions at small spatial scales in Bangladesh should consider the social and socio-economic risk factors identified as well as alternative methods for improving equity of access to interventions across whole communities.
War and Agriculture: Three Decades of Agricultural Land Use and Land Cover Change in Iraq Dataset
Gibson, Glen R. (2012-05-09)
War and geopolitical forces are important drivers of land use and land cover change, and agricultural regions are the most susceptible to those types of changes. Iraq has suffered more than three decades of near-continuous war and instability, including the Iran-Iraq War (1980 to 1988), the Gulf War (1990 to 1991), comprehensive economic sanctions (1990 to 2003), and Operation Iraqi Freedom (OIF) (2003 to 2011). During these conflicts, Iraq’s landscapes were observed by civil satellite remote sensing systems. However, I found little published research applying remote sensing to assess the long-term effects of war on Iraq’s agricultural land cover. The main objective of this dissertation is to assess whether cultivated area in Iraq, as estimated using satellite remote sensing, changed during and as a result of war and sanctions, and to determine where and when changes occurred. The dissertation is composed of three studies. The first study uses MODIS NDVI data during the OIF and the end of UN sanctions to study changes in cultivated area for Iraq as a whole and to identify spatial patterns and temporal differences related to crop type. The second study uses Landsat images converted to NDVI to study changes in cultivated area in central Iraq for all four periods of conflict listed above, and relates those changes to effects on food security. Finally, the third study builds on findings from the second study to address patterns of agricultural land abandonment in central Iraq as related to three drivers: ecological, socio-economic, and land mismanagement. The overall findings indicate that the UN sanctions had the greatest impact on cultivated area, increasing during sanctions when food imports all but ceased and decreasing after the sanctions had ended and food imports resumed, significantly affecting land use and food security. README ======= When all files are downloaded and extracted, the file structure is as shown in contents.txt These contents are archived in multi-volume tar files using the following command: printf 'n Gibson_Iraq-%03d.tar\n' {2..1000} | tar -ML 200000 -cf Gibson_Iraq-001.tar Gibson_Iraq/ Note, only GNU tar version 1.23 or newer (e.g., Red Hat/CentOS Linux version 6.x contains tar version 1.23) may be used to create and extract the tar files. Older versions contain a bug and cannot properly extract files across volumes when long file paths/names are present. Contents in each tar file are shown in contents_tar.txt You may only download the tar volume containing the files you need, then extract this single tar volume. If a file spans across multiple volumes, you'll need to download all related volumes and extract them together. For example, if you download Gibson_Iraq-480.tar to Gibson_Iraq-486.tar and want to extract all the contents in these volumes, run this command: printf 'n Gibson_Iraq-%03d.tar\n' {481..486} | tar --extract --multi-volume --file=Gibson_Iraq-480.tar
Does availability of physical activity and food outlets differ by race and income? Findings from an enumeration study in a health disparate region
Hill, Jennie L.; Chau, Clarice; Luebbering, Candice R.; Kolivras, Korine N.; Zoellner, Jamie M. (2012-09-06)
Background Low-income, ethnic/racial minorities and rural populations are at increased risk for obesity and related chronic health conditions when compared to white, urban and higher-socio-economic status (SES) peers. Recent systematic reviews highlight the influence of the built environment on obesity, yet very few of these studies consider rural areas or populations. Utilizing a CBPR process, this study advances community-driven causal models to address obesity by exploring the difference in resources for physical activity and food outlets by block group race and income in a small regional city that anchors a rural health disparate region. To guide this inquiry we hypothesized that lower income and racially diverse block groups would have fewer food outlets, including fewer grocery stores and fewer physical activity outlets. We further hypothesized that walkability, as defined by a computed walkability index, would be lower in the lower income block groups. Methods Using census data and GIS, base maps of the region were created and block groups categorized by income and race. All food outlets and physical activity resources were enumerated and geocoded and a walkability index computed. Analyses included one-way MANOVA and spatial autocorrelation. Results In total, 49 stores, 160 restaurants and 79 physical activity outlets were enumerated. There were no differences in the number of outlets by block group income or race. Further, spatial analyses suggest that the distribution of outlets is dispersed across all block groups. Conclusions Under the larger CPBR process, this enumeration study advances the causal models set forth by the community members to address obesity by providing an overview of the food and physical activity environment in this region. This data reflects the food and physical activity resources available to residents in the region and will aid many of the community-academic partners as they pursue intervention strategies targeting obesity.
Landscape Dynamics on the Island of La Gonave, Haiti, 1990-2010
White, Justin H.; Shao, Yang; Kennedy, Lisa M.; Campbell, James B. Jr. (MDPI, 2013-09-16)
The island of La Gonave lies northwest of Port-au-Prince and is representative of the subsistence Haitian lifestyle. Little is known about the land cover changes and conversion rates on La Gonave. Using Landsat images from 1990 to 2010, this research investigates landscape dynamics through image classification, change detection, and landscape pattern analysis. Five land cover classes were considered: Agriculture, Forest/Dense Vegetation (DV), Shrub, Barren/Eroded, and Nonforested Wetlands. Overall image classification accuracy was 87%. Results of land cover change analysis show that all major land cover types experienced substantial changes from 1990 to 2010. The area percent change was _39.7, _22.7, 87.4, and _7.0 for Agriculture, Forest/Dense Vegetation, Shrub, and Barren/Eroded. Landscape pattern analysis illustrated the encroachment of Shrub cover in core Forest/DV patches and the decline of Agricultural patch integrity. Agricultural abandonment, deforestation, and forest regrowth combined to generate a dynamic island landscape, resulting in higher levels of land cover fragmentation.
Comparing Urban Impervious Surface Identification Using Landsat and High Resolution Aerial Photography
Parece, Tammy E.; Campbell, James B. Jr. (MDPI, 2013-10-10)
This paper evaluates accuracies of selected image classification strategies, as applied to Landsat imagery to assess urban impervious surfaces by comparing them to reference data manually delineated from high-resolution aerial photos. Our goal is to identify the most effective methods for delineating urban impervious surfaces using Landsat imagery, thereby guiding applications for selecting cost-effective delineation techniques. A high-resolution aerial photo was used to delineate impervious surfaces for selected census tracts for the City of Roanoke, Virginia. National Land Cover Database Impervious Surface data provided an overall accuracy benchmark at the city scale which was used to assess the Landsat classifications. Three different classification methods using three different band combinations provided overall accuracies in excess of 70% for the entire city. However, there were substantial variations in accuracy when the results were subdivided by census tract. No single classification method was found most effective across all census tracts; the best method for a specific tract depended on method, band combination, and physical characteristics of the area. These results highlight impacts of inherent local variability upon attempts to characterize physical structures of urban regions using a single metric, and the value of analysis at finer spatial scales.
Institutions for managing common-pool resources: The case of community-based shrimp aquaculture in northwestern Sri Lanka
Galappaththi, Eranga K.; Berkes, Fikret (2014)
Large-scale shrimp aquaculture can have major social and environmental impacts. Can community-based approaches be used instead? We examined three coastal community-based shrimp aquaculture operations in northwestern Sri Lanka using a case study approach. These shrimp farms were individually owned by small producers and managed under community-level rules. The system was characterized by three layers of institutions: community-level shrimp farmers’ associations; zone-level associations; and a national-level shrimp farming sector association. The national level was represented by a joint body of government and sector association. We evaluated the effectiveness of this institutional structure especially with regard to the management of shrimp disease that can spread through the use of a common water body. Lower operational costs make them a highly attractive alternative to large-scale aquaculture. In many ways, private shrimp aquaculture ownership with community-level institutions, and government supervision and coordination seem to work well.
Conservation and Unscripted Development: Proximity to park associated with development and financial diversity
Baird, Timothy D. (The Resilience Alliance, 2014)
Decades of research on the social dynamics of biodiversity conservation has shown that parks and protected areas have added hardship to rural communities throughout much of the developing world. Nonetheless, some recent studies have found evidence of poverty alleviation near protected areas. To build on these conflicting accounts, I use a comparative, mixed-methods design to examine opportunistic, unplanned, i.e., unscripted, development in indigenous communities near Tarangire National Park (TNP) in northern Tanzania. I ask the questions: (1) How is proximity to TNP related to community-level infrastructural development? (2) How has the process of development changed over time? and (3) How is proximity to TNP related to infrastructure-related social outcomes at the household-level? Results from semistructured interviews show that, compared with distant communities, communities near TNP have developed more extensive education and water infrastructure in the past decade by procuring financial support from a greater diversity of external organizations, including wildlife-related organizations. Correspondingly, household survey results show that education measures are positively associated with proximity to TNP, controlling for other factors. These findings support the notion that development can accrue near protected areas in ways that are diverse, uncoordinated, and opportunistic, and correspondingly distinct from heralded community-based conservation, community-based natural resource management, and integrated conservation and development project initiatives.
Developing a Topographic Model to Predict the Northern Hardwood Forest Type within Carolina Northern Flying Squirrel (Glaucomys sabrinus coloratus) Recovery Areas of the Southern Appalachians
Evans, Andrew M.; Odom, Richard H.; Resler, Lynn M.; Ford, W. Mark; Prisley, Stephen P. (Hindawi, 2014-08-28)
The northern hardwood forest type is an important habitat component for the endangered Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus) for den sites and corridor habitats between boreo-montane conifer patches foraging areas. Our study related terrain data to presence of northern hardwood forest type in the recovery areas of CNFS in the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. We recorded overstory species composition and terrain variables at 338 points, to construct a robust, spatially predictive model. Terrain variables analyzed included elevation, aspect, slope gradient, site curvature, and topographic exposure. We used an information-theoretic approach to assess seven models based on associations noted in existing literature as well as an inclusive global model. Our results indicate that, on a regional scale, elevation, aspect, and topographic exposure index (TEI) are significant predictors of the presence of the northern hardwood forest type in the southern Appalachians. Our elevation + TEI model was the best approximating model (the lowest AICc score) for predicting northern hardwood forest type correctly classifying approximately 78% of our sample points. We then used these data to create region-wide predictive maps of the distribution of the northern hardwood forest type within CNFS recovery areas.
Compassionately Hidden: The Church Telling Local Homeless to “Come to Our House"
Oliver, Robert D.; Robinson, Matthew; Koebel, C. Theodore (Gamma Theta Upsilon, 2015)
In early 2011, the To Our House (TOH) thermal shelter program opened its doors to homeless men in the New River Valley Area (NRV) of Virginia. The program was a grass roots response to the death of a well-known local homeless man and the goal of the program is to provide winter shelter for single adult men by using rotating host sites at local churches. We highlight that in the NRV local churches have sought to remedy a socially unjust situation by providing shelter for men that was previously unavailable. We illustrate that faith-based outreach in the New River Valley can be viewed as positive compassionate outreach by a caring community. While acknowledging the benefits of this compassionate outreach to more than 25 men in the NRV, we also offer a cautionary note regarding the dilemmas of this outreach suggesting that it has the potential to mask the problems of the local housing market.
Trust ecology and the resilience of natural resource management institutions
Stern, Marc J.; Baird, Timothy D. (The Resilience Alliance, 2015)
The resilience of natural resource management (NRM) institutions are largely contingent on the capacities of the people and organizations within those institutions to learn, innovate, and adapt, both individually and collectively. These capacities may be powerfully constrained or catalyzed by the nature of the relationships between the various entities involved. Trust, in particular, has been identified repeatedly as a key component of institutional relationships that supports adaptive governance and successful NRM outcomes. We apply an ecological lens to a pre-existing framework to examine how different types of trust may interact to drive institutional resilience in NRM contexts. We present the broad contours of what we term “trust ecology,” describing a conceptual framework in which higher degrees of diversity of trust, as conceptualized through richness and evenness of four types of trust (dispositional, rational, affinitive, and systems based), enhance both the efficacy and resilience of NRM institutions. We describe the usefulness and some limitations of this framework based on several case studies from our own research and discuss the framework's implications for both future research and designing more resilient governance arrangements.
Drama of the commons in small-scale shrimp aquaculture in northwestern Sri Lanka
Galappaththi, Eranga K.; Berkes, Fikret (Uopen Journals, 2015-01-01)
Aquaculture, and shrimp aquaculture in particular, can have major social and environmental impacts. However, aquaculture remains an understudied area in commons research. Can aspects of commons theory be applied to solve problems of aquaculture? We examined three coastal community-based shrimp aquaculture operations in northwestern Sri Lanka using a case study approach. These shrimp farms were individually owned by small producers and managed under local-level rules designed by cooperatives (samithi). The common-pool resource of major interest was water for aquaculture ponds, obtained from an interconnected water body. We evaluated the shrimp farming social-ecological system by using Ostrom’s design principles for collective action. Key elements of the system were: clearly defined boundaries; collaboratively designed crop calendar, bottom-up approach involving community associations, multi-level governance, and farmers-and-government collaborative structures. Together, these elements resolved the excludability and subtractability problems of commons by establishing boundary and membership rules and collective choice rules.
Introduction to the Special Issue “The Intersection of Society and Watershed Science”
Younos, Tamim M.; Parece, Tammy E.; Armel, Alaina J. (MDPI, 2015-08-07)
Despite significant advances in watershed science and technology, water availability, water quality, and water related health problems remain a significant worldwide concern [1]. While the concept of watershed-scale management to address these concerns remains intact, most scientists recognize that application of natural science concepts and advanced technologies are not sufficient to adequately address watershed-scale water management issues. There is a significant need for a paradigm shift, i.e., namely increased public interaction and participation in watershed management and decision-making. The effective application of an integrated approach requires developing new scientific concepts on integration of natural and social sciences. In recent years, concepts, such as integrated watershed management and/or holistic approaches to water resource management, have been widely promoted (e.g., [2–6]). [...]
Women, Gender Norms, and Natural Disasters: Examples from South Asia
Juran, Luke (Virginia Tech. University Libraries, 2015-10-15)
Women and men are impacted differently by disasters, leading to claims that there exists a "gendered terrain of disasters." South Asia is a region where this confluence of gender and disaster is particularly relevant. Thus, data from South Asia will be presented to demonstrate that women are more vulnerable than men before, during, and after disasters. Ultimately, the biological variable of being female (sex) fails to fully account for gaps in morbidity and mortality; rather socially constructed variables (gender) are responsible for such disparities in South Asia and across space. The presenter is Dr. Luke Juran, Assistant Professor in the Department of Geography and the Virginia Tech Water Resources Research Center. This event is part of the Women and Gender in International Development (WGD) discussion series. This program gives students and professionals an opportunity to share their research and discuss issues of Women and Gender in International Development. Students, faculty, staff, and members of the community are encouraged to attend the discussions and bring their ideas and questions.
Assessing Urban Landscape Variables’ Contributions to Microclimates
Parece, Tammy E.; Li, Jie; Campbell, James B. Jr.; Carroll, David F. (Hindawi, 2015-12-24)
The well-known urban heat island (UHI) effect recognizes prevailing patterns of warmer urban temperatures relative to surrounding rural landscapes. Although UHIs are often visualized as single features, internal variations within urban landscapes create distinctive microclimates. Evaluating intraurban microclimate variability presents an opportunity to assess spatial dimensions of urban environments and identify locations that heat or cool faster than other locales. Our study employs mobile weather units and fixed weather stations to collect air temperatures across Roanoke, Virginia, USA, on selected dates over a two-year interval. Using this temperature data, together with six landscape variables, we interpolated (using Kriging and Random Forest) air temperatures across the city for each collection period. Our results estimated temperatures with small mean square errors (ranging from 0.03 to 0.14); landscape metrics explained between 60 and 91% of temperature variations (higher when the previous day’s average temperatures were included as a variable). For all days, similar spatial patterns appeared for cooler and warmer areas in mornings, with distinctive patterns as landscapes warmed during the day and over successive days. Our results revealed that the most potent landscape variables vary according to season and time of day. Our analysis contributes new dimensions and new levels of spatial and temporal detail to urban microclimate research.
Remote Sensing of Tillage Status
Zheng, Baojuan; Campbell, James B. Jr.; Serbin, Guy; Daughtry, Craig S. T.; McNairn, Heather; Pacheco, Anna (2016)
Remote Sensing of Tillage Status is Chapter 8 in the book Land Resources Monitoring, Modeling, and Mapping With Remote Sensing.
Data Management Bootcamp 2016: Peter Sforza
Sforza, Peter M. (Virginia Tech. University Libraries, 2016-01-15)

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