Ph.D. (Geography) / Please refer to full text to view abstract

The objective of this paper is to develop a well-defined and sound framework for the implementation of a multi-participant GIS program and to illustrate the developed framework by its application to the Departments of the Town of Blacksburg. A multi-participant approach to implementing GIS technology faces greater challenges than a single-participant GIS project, due to the unique culture, structure, policy, decision-making rule and expectations of participants from implementation of GIS technology. So a successful program depends upon aligning different characteristics of the program's structure to those of participants, individually and collectively. Maximizing the system's potentials necessitates a well-defined implementation framework that can help manage changes and integrate the technology in organizations. Therefore, the paper focuses on the implementation aspects of multi-participant GIS programs. The paper achieves its objective by exploring various issues involved in the implementation process of GIS technology and multi-participant GIS programs, develops a framework for implementing a multi-participant GIS program and applies the framework to the Departments of the Town of Blacksburg to achieve successful implementation. The illustration of the Town of Blacksburg identifies various constraints for multi-participant GIS program for which recommendations are provided to achieve successful implementation. / Master of Urban and Regional Planning

Accurate and replicable measurements of changes to land cover from drought conditions are essential for monitoring ecosystem disturbances. Techniques designed to measure land cover changes have been developed using data from remote sensing but with variable success. In my three study areas of southeastern parts of the American State of Texas, the change vector analysis (CVA) technique was tested on remote sensing data captured by the Landsat TM sensor taken in the years 2009, 2010, and 2011. This study monitors land use/land cover (LULC) changes due to the extreme Texas drought of 2011; the worst single year drought ever recorded in the state. The Landsat data are converted to vegetation indices; the normalized difference vegetation index (NDVI), bare soil index (BI), normalized difference moisture index (NDMI), as well as Tasseled Cap Transformations (TCT) brightness, greenness and wetness. CVA was used to determine the intensity of change (magnitude) and the type of changes that occurred (direction) between the multi-temporal data. This represents a new and improved method for calculating the direction component. Additionally, the relationship between NDVI and NDMI and between TCT variables and their application in CVA are further explored. The results show that land cover changes occurred due to an increase in precipitation in 2010 as well as considerable decrease of precipitation in 2011 resulting in the devastating drought. Validation procedures show that the CVA method was effective in capturing both magnitude of change and type of change that occurred. The remote sensing approach to monitoring drought-induced land cover changes is systematic, replicable and globally available at any time. Such a reliable methodology is essential for measuring ecosystem threats and human population vulnerability. / A Dissertation submitted to the Department of Geography in partial fulfillment of the Doctor of Philosophy. / Spring Semester 2017. / March 31, 2017. / Change vector analysis, Drought, Landsat, Remote sensing / Includes bibliographical references. / Victor Mesev, Professor Directing Dissertation; Xiuwen Liu, University Representative; Stephanie Pau, Committee Member; Xiaojun Yang, Committee Member.

The simulation of overland flow accumulation is critical for drainage network extraction, soil moisture monitoring, and hydrological modeling, etc. A variety of flow accumulation algorithms have been developed, but the complex and variable terrain has undermined their predictive accuracy. In my dissertation, a new flow accumulation algorithm (SAPC) is proposed that applies different flow distribution schemes to divergent and convergent flow scenarios with respect to slope, aspect, and plan curvature. Flow accumulation for the divergent scenario is slope-driven in the sense that flow distributed to the downslope neighboring cells is proportional to the slope values, and the weight of slope varies with plan curvature, making the SAPC algorithm adaptable to the variation of terrain surface. For the convergent scenario, flow accumulation is determined by aspect and all the water in the center cell is distributed in the same direction in two dimensions. Comparisons between the SAPC algorithm and the other algorithms show that flow accumulations estimated by the SAPC algorithm are closer to the true values for artificial surfaces, and the generated flow pathways are more balanced and smoother without serious artifacts for natural terrain surfaces. The SAPC algorithm is further integrated into the WetSpa Extension model to simulate hydrological responses at the outlet of the Bull Creek watershed for the 100-year tropical storm Hermine occurring in September 2010. The WetSpa Extension model provides both the semi-distributed and the fully-distributed modeling options. The fully-distributed WetSpa Extension model predicts a higher amount of surface runoff and thus the peak flow approaches more to the observed value than that predicted by the semi-distributed model. Flow accumulation is an important spatial parameter involved in hydrological modeling, and specifically it affects flow routing. Incorporating the SAPC algorithm into the WetSpa Extension model helps to obtain a hydrograph that aligns closer to the observed high flow region and more importantly, the model is able to provide the correct time to peak, otherwise there is half an hour of delay in the time to peak when SAPC algorithm is not used. Statistics demonstrate that the SAPC algorithm enables the WetSpa Extension model to be less biased, more confident and efficient. The significance of this dissertation lies in its provision of the possible ways to enhance the adaptability of flow accumulation algorithm to the varying terrain surfaces, and to improve hydrological modeling results through the more accurate and reliable flow accumulation predictions. This interdisciplinary study, which involves terrain analysis, hydrological modeling, and geographic information science (GIS), stresses the importance of location in describing physical features and processes that is usually the focus of geographical investigation. / A Dissertation submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2019. / March 29, 2019. / Distributed hydrological modeling, Flow accumulation algorithm, Geographic information science, Python, WetSpa Extension model / Includes bibliographical references. / Victor Mesev, Professor Directing Dissertation; Christopher J. Coutts, University Representative; Xiaojun Yang, Committee Member; Tingting Zhao, Committee Member.

see document / Master of Science

Digital satellite remote sensing and Geographic Information Systems (GIS) have been used in conjunction with the Universal Soil Loss Equation (USLE) to model soil erosion potential within watersheds. This study compared erosion estimates calculated by the remote sensing method to results obtained in the field by soil conservationists using conventional methods.

Predictive models have established a niche in the field of archaeology. Valued as tools in predicting potential archaeological sites, their use has increased with development of faster and more affordable computer technology. Predictive models highlight areas within a landscape where archaeological sites have a high probability of occurrence. Therefore, time and resources normally expended on archaeological exploration can then be more efficiently allocated to specified locations within a study area. In addition to the resulting predictive surface, these models also identify significant variables for site selection by prehistoric or historic groups. Relationships with the environment, whether natural or social, are extremely pertinent to strengthening the resource base. In turn, this information can be utilized to better interpret and protect valuable cultural resources. A predictive probability model was generated to locate Union Civil War fortifications around Petersburg, Virginia. This study illustrated the ease with which such analysis can be accomplished with the integrated use of a Geographic Information System with statistical analysis. Stepwise logistic regression proved effective in selecting significant independent variables to predict probabilities of fortifications within the study area, but faired poorly when applied to areas withheld from the initial building stage of the model. Variation of battle tactics between these two separate areas proved great enough to have a detrimental effect the model's effectiveness. / Master of Science

Over the past half century, archaeologists have been interested in how the environmental variation of the Central Coast has affected settlement patterns. Archaeologists relied on ethnography and subsistence models to explain settlement distribution but were unable to analytically demonstrate influencing factors. The objectives of this thesis were to investigate: (1) the spatial arrangement of sites to examine the types of locations people utilized; and (2) test if the occupational history of a site is reflected by its geographic locations. In this project, site dimension was used as a relative indicator of settlement occupational intensity, and over twenty environmental attributes were tested. Analysis was systematically conducted at multiple spatial scales using GIS. In the first stage the location of shell middens (n=351) were compared against an environmental baseline, derived from a sample of random points. For the second stage, small and large shell middens were compared to test if their locations significantly differed. It was found that shell middens do show an association with certain environmental settings. For some attributes, there was an observable difference in the location of large and small shell middens. However, immense variability was identified and the environmental context of sites greatly determined whether locational preferences could be empirically demonstrated. Overall, large middens, more so than small middens, are located in areas with higher resource diversity. These conclusions support other studies that indicate the relevance of multiple determinants and emphasizes the local nuances of settlement patterning affected by environmental and cultural factors. My results oppose the simplistic and static notion about a prehistoric annual cycle of sedentary winter villages and seasonal resource-specific camps. Improvements to an understanding of settlement distribution can aid in contextualizing specific sites within their regional setting and contribute to our knowledge regarding larger cultural practices such as subsistence and land use practices. / Thesis / Master of Arts (MA)

Route reconnaissance has been valuable for military commanders for centuries. Engineering forces are specifically tasked to gather route reconnaissance intelligence to present to the maneuver commander. US Army Engineers presently use a variety of highly technological methods to collect, process, and present this detailed route reconnaissance intelligence. This thesis examines and analyzes the capabilities of four reconnaissance groups. Using a matrix, each of the four units is ranked based on surveys of reconnaissance officers and on the personal experience of the author of this thesis. Results show that Unit 2 (FEST-M) is the most qualified unit to collect detailed geospatial route reconnaissance of the battlefield. The ARRK/TETK software system has helped this unit rise to the top over the other reconnaissance unit types analyzed. The need for geospatial route reconnaissance will continue to be a part of the modern day battlefield and will change constantly as technology is updated.

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