This thesis explores how digital representations of geography and Geographic Information (GI) may be described, and how these descriptions facilitate the use of the resources they depict. More specifically, it critically examines existing geospatial documentation practices and aims to identify opportunities for refinement therein, whether when used to signpost those data assets documented, for managing and maintaining information assets, or to assist in resource interpretation and discrimination. Documentation of GI can therefore facilitate its utilisation; it can be reasonably expected that by refining documentation practices, GI hold the potential for being better exploited. The underpinning theme connecting the individual papers of the thesis is one of multi-granular documentation. GI may be recorded at varying degrees of granularity, and yet traditional documentation efforts have predominantly focussed on a solitary level (that of the geospatial data layer). Developing documentation practices to account for other granularities permits the description of GI at different levels of detail and can further assist in realising its potential through better discovery, interpretation and use. One of the aims of the current work is to establish the merit of such multi-granular practices. Over the course of four research papers and a short research article, proprietary as well as open source software approaches are accordingly presented and provide proof-of-concept and conceptual solutions that aim to enhance GI utilisation through improved documentation practices. Presented in the context of an existing body of research, the proposed approaches focus on the technological infrastructure supporting data discovery, the automation of documentation processes and the implications of describing geospatial information resources of varying granularity. Each paper successively contributes to the notion that geospatial resources are potentially better exploited when documentation practices account for the multi-granular aspects of GI, and the varying ways in which such documentation may be used. In establishing the merit of multi-granular documentation, it is nevertheless recognised in the current work that instituting a comprehensive documentation strategy at several granularities may be unrealistic for some geospatial applications. Pragmatically, the level of effort required would be excessive, making universal adoption impractical. Considering however the ever-expanding volumes of geospatial data gathered and the demand for ways of managing and maintaining the usefulness of potentially unwieldy repositories, improved documentation practices are required. A system of hierarchical documentation, of self-documenting information, would provide for information discovery and retrieval from such expanding resource pools at multiple granularities, improve the accessibility of GI and ultimately, its utilisation.

A process allowing for the intuitive use of SQL queries on dense multidimensional data stored in Network Common Data Format (netCDF) files is developed using advanced bitmap indexing provided by the FastBit bitmap indexing tool. A method for netCDF data extraction and FastBit index creation is presented and a geospatial Range and pseudo-KNN search based on the haversine function is implemented via SQL. A two step filtering algorithm is shown to greatly enhance the speed of these geospatial queries, allowing for extremely efficient processing of the netCDF data in bitmap indexed form.

A Research Report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2016. / Countries around the world are recognising the importance of geospatial data in answering questions related to spatially varying industries such as mining activities (ongoing and discontinued). This is becoming increasingly evident with countries such as Canada, Australia, and the United Kingdom working towards establishing Abandoned Mine Lands (AML) inventories. However, the increasing need for data on mining activities is not paralleled by an increase in the availability of such data. The aim of this research therefore is to design a database for accessing historical and current geospatial data that can be used to support research, environmental management efforts as well as support decision making at all levels. A user needs survey was conducted. Two sampling methods were employed, convenient sampling and snowball sampling method. The convenient sampling method was used mostly with all the WDMP group members and the latter was employed with the respondents from institutions and organisations outside of the university respectively. The data were then categorised so as to make analysis easier and data could be evaluated on the same basis. An evaluation of the data collected showed that although the WDMP required different types of data (spatial and non- spatial) the data feed into each other and as such it is important that there is a central repository in which to store them. Furthermore investigation also shows that there is a wealth of data on current mining activities, but not so much on historical mining activities. Although data on mining activities exists, accessibility to these data is hindered by various factors such as copyright infringements, data costs, discrepancies in the data request process. The outcome of this research has been that of a physical database PostgreSQL database (PostGIS) and one mounted on an online platform (GeoServer). The databases can be visualised on PostgreSQL using select statements or visualisation through establishing a connection with QGIS, alternatively the database may be accessed on GeoServer. The database is expected to be of use to at least all members of the Wits Digital Mine Project (WDMP) and stakeholders involved in the project. The database can be used for baseline studies and also as a basis for the framework used to analyse, remedy as well as predict future challenges in the mining industry. Moreover, the database can act as a central repository for all data produced from the WDMP. / LG2017

The growing importance of geospatial databases has made it essential to perform complex spatial queries efficiently. To achieve acceptable performance levels, database systems have been increasingly required to make use of parallelism. The spatial join is a computationally expensive operator. Efficient implementation of the join operator is, thus, desirable. The work presented in this document attempts to improve the performance of spatial join queries by distributing the data set across several nodes of a cluster and executing queries across these nodes in parallel. This document discusses a new parallel algorithm that implements the spatial join in an efficient manner. This algorithm is compared to an existing parallel spatial-join algorithm, the clone join. Both algorithms have been implemented on a Beowulf cluster and compared using real datasets. An extensive experimental analysis reveals that the proposed algorithm exhibits superior performance both in declustering time as well as in the execution time of the join query.

Demographic and Demand Characteristics of Carsharing: A Case Study of Austin, Texas explores the use of geospatial analysis in order to understand the demand characteristics and market for carsharing services. A literature review was performed and the demographic characteristics of typical users of carsharing were established. A series of maps was created to geospatially identify concentrations of typical users and their location and access in reference to carsharing vehicle locations. The greater urbanized area of Austin, Texas located within Travis County was used as a case study for this analysis. The report demonstrates that geospatial analysis is a valuable tool to understand the spatial relationship between typical carshare users, nontypical carshare users and the placement of carshare vehicles. / text

The overarching objective of this dissertation was to study groundwater resources on global, local, and regional scales. The first objective of this dissertation was to analyze the groundwater nitrate contamination in the Edwards-Trinity and the Southern High-Plains aquifers of Texas. The second was to study groundwater quality in terms of seawater intrusion in the California Coastal Basin, Upper Floridian, and North Atlantic Coastal Plain aquifers. This dissertation also provided a comprehensive overview of the groundwater level in basins at the global scale and further analyzed agricultural activities on groundwater storage in small and large basins. To achieve first objective, Ordinary Least Square (OLS) and Geographically Weighted Regression (GWR) models were used to study the relationship between groundwater nitrate contamination and land use. This dissertation further identified dominant groundwater types using USGS well data and to estimate the extent of seawater intrusion in terms of dominant ions and ocean salinity in the United States coastal aquifers. Finally, groundwater storage anomaly was quantified using Gravity Recovery and Climate Experiment (GRACE) derived variations in total Terrestrial Water Storage (TWS) and the Global Land Data Assimilation System (GLDAS). Land cover data representing a percentage of irrigated lands using groundwater resources was used to study agricultural activities on groundwater storage. Groundwater nitrate contamination was positively associated with cotton production in Southern High-Plains and Edwards-Trinity aquifers. The nitrate concentrations tended to increase as the well-depth decreased in both aquifers. Results showed that the dominant ions in the study area were Na+ and Cl- . The study concluded that Na-Cl and mixed Ca-Mg-Cl were dominant water types in the United States' coastal aquifers. Results also indicated that seawater intrusion is occurring in the US coastal aquifers. Groundwater depletion has increased in southern Asia, western North America, and southwestern Europe due to groundwater withdrawal for agricultural use. However, farming practice is not the main reason for groundwater scarcity in South America, Africa, and Australia.

This research examines the role of geospatial and ancillary technologies in the erosion of privacy in contemporary society. The development of Remote Sensing, GIS, and GPS technologies are explored as a means of understanding both their current and predicted uses and capabilities. Examination is also made of the legal basis and current status of privacy rights in the United States. Finally, current and predicted uses and capabilities of geospatial and ancillary technologies are critically examined in light of existing privacy protections as a means of determining the ways in which these technologies are impacting privacy currently and what their effects may be in the future.

The goal of this research is to provide a supporting Web services architecture, consisting of a service model and catalog, to allow discovery and automatic orchestration of geospatial Web services. First, a methodology for supporting geospatial Web services with existing orchestration tools is presented. Geospatial services are automatically translated into SOAP/WSDL services by a portable service wrapper. Their data layers are exposed as atomic functions while WSDL extensions provide syntactic metadata. Compliant services are modeled using the descriptive logic capabilities of the Ontology Language for the Web (OWL). The resulting geospatial service model has a number of functions. It provides a basic taxonomy of geospatial Web services that is useful for templating service compositions. It also contains the necessary annotations to allow discovery of services. Importantly, the model defines a number of logical relationships between its internal concepts which allow inconsistency detection for the model as a whole and for individual service instances as they are added to the catalog. These logical relationships have the additional benefit of supporting automatic classification of geospatial services individuals when they are added to the service catalog. The geospatial service catalog is backed by the descriptive logic model. It supports queries which are more complex that those available using standard relational data models, such as the capability to query using concept hierarchies. An example orchestration system demonstrates the use of the geospatial service catalog for query evaluation in an automatic orchestration system (both fully and semi-automatic orchestration). Computational complexity analysis and experimental performance analysis identify potential performance problems in the geospatial service catalog. Solutions to these performance issues are presented in the form of partitioning service instance realization, low cost pre-filtering of service instances, and pre-processing realization. The resulting model and catalog provide an architecture to support automatic orchestration capable of complementing the multiple service composition algorithms that currently exist. Importantly, the geospatial service model and catalog go beyond simply supporting orchestration systems. By providing a general solution to the modeling and discovery of geospatial Web services they are useful in any geospastial Web service enterprise.

Student Number :9600874K - MSc research report - School of Electrical Engineering - Faculty of Engineering and the Built Environment / Telecommunication networks have evolved from voice only single service networks to multimedia networks providing bearer services such as voice, data and video transportation. Moreover, these networks, collectively called Next Generation Networks (NGNs), enable rapid creation, deployment and management of advanced services in an efficient manner. However, the initial business model of telcos was to internally develop and provide these advanced services to customers. In this monopolized environment, service development is driven by technological availability rather than customer demands. Furthermore, vendor specific network elements prohibit the development of re-useable service components, which in turn increases the time-to-market of services. Deregulation and advances in Distributed Computing Systems (DCSs) are driving towards open networks and rapid service delivery. Third party Application Service Providers (ASPs) are envisioned to develop and supply the services, with the telco providing bearer services. The use of softswitch architectures such as Open Service Access (OSA) / Parlay (OSA / Parlay) in an open NGN environment abstract services from core network elements through its Application Programming Interface (API). Services are thus decoupled from vendor and protocol specific network equipment and can be provided across a plethora of network architectures. One major advantage of NGN is the ability to provide bearer service in a mobile environment. Location Based Services (LBSs) are envisaged to be an important class of services provided in the NGN environment. For an LBS service to be complete, a geospatial database is necessary to provide location information. This report documents the design and implementation of a Geospatial Data Access Service Capability Feature (GDASCF) as an extension to the OSA / Parlay gateway. The GDASCF encapsulates necessary APIs that offer uniform access to query geospatial databases. One key component of the design is the realization of the Adapter layer which adapts function calls to an appropriate Database Management System (DBMS). The introduction of the GDASCF and Adapter layer provides a solution which results in flexible and rapid service creation.

Wildland fire fighting is complex due to climatic variation, risk and uncertainty, and the proximity of human and resource values. Information about fire environments, resource availability and logistics, fire behavior, and values at risk are important issues fire managers must consider in allocating scarce resources. Improved information thus, has value in reducing risk and costs and damages. Geospatial technology, which includes remote sensing tools, geographic positioning systems (GPS), geographic information systems (GIS) and various maps are widely used in wildland fire management. My research evaluates geospatial tools in three different ways: their role in risk reduction, their effect on wildland fire costs and damages, and wildland fire managers perceived costs and benefits.<p> A theoretical model was developed to analyze the role of geospatial tools in reducing the risk. Risk-averse fire managers were found to use more geospatial technologies compared to those who did not incorporate risk in their decision making, resulting in a creation of value for these technologies. A simultaneous equation system of fires was estimated using the two-stage and the three-stage least squares estimation methods to examine the impact of geospatial tools on fire size, cost and damages. The effect of geospatial technology on fire size was significant in the Full Response Zone. Fire size was positively related to drought and duff moisture codes. Damages and cost of suppression were not affected significantly by the use of digitized maps. The survey of wildland fire managers revealed that geospatial tools are useful in integrating information and provide more clarity, flexibility and accuracy in decision-making. It was also discovered in the survey that geospatial tools are most commonly used when multiple fires are burning at the same time and threatening high resource values. Overall, the findings from this research indicated that risk-averse fire managers use geospatial tools more intensively; that maps play a significant role in reducing the fire size in the Full Response Zone, and, finally, the fire managers view that these technologies are more economically efficient in the Full Response Zone makes a case for more investment in developing and employing them on fires. Record keeping and data collection as well as understanding the human element in terms of risk aversion will be important for future studies and for adopting new technology and allocating resources efficiently.