20 research outputs found
Remote sensing and GIS in support of sustainable agricultural development
Over the coming decades it is expected that the vast amounts of area currently in agricultural production will face growing pressure to intensify as world populations continue to grow, and the demand for a more Western-based diet increases. Coupled with the potential consequences of climate change, and the increasing costs involved with current energy-intensive agricultural production methods, meeting goals of environmental and socioeconomic sustainability will become ever more challenging. At a minimum, meeting such goals will require a greater understanding of rates of change, both over time and space, to properly assess how present demand may affect the needs of future generations. As agriculture represents a fundamental component of modern society, and the most ubiquitous form of human induced landscape change on the planet, it follows that mapping and tracking changes in such environments represents a crucial first step towards meeting the goal of sustainability. In anticipation of the mounting need for consistent and timely information related to agricultural development, this thesis proposes several advances in the field of geomatics, with specific contributions in the areas of remote sensing and spatial analysis: First, the relative strengths of several supervised machine learning algorithms used to classify remotely sensed imagery were assessed using two image analysis approaches: pixel-based and object-based. Second, a feature selection process, based on a Random Forest classifier, was applied to a large data set to reduce the overall number of object-based predictor variables used by a classification model without sacrificing overall classification accuracy. Third, a hybrid object-based change detection method was introduced with the ability to handle disparate image sources, generate per-class change thresholds, and minimize map updating errors. Fourth, a spatial disaggregation procedure was performed on coarse scale agricultural census data to render an indicator of agricultural development in a spatially explicit manner across a 9,000 km2 watershed in southwest Saskatchewan for three time periods spanning several decades. The combination of methodologies introduced represents an overall analytical framework suitable for supporting the sustainable development of agricultural environments
Estimation of population using satellite imagery
The basic aims of this research were twofold; to extend and refine statistical image analysis methodologies for directly estimating small area populations and population densities from Landsat TM images and to validate procedures developed and to explore their robustness to geographical and seasonal differences within Australia, and hence to explore the potential of this methodology to provide a genuine operational alternative to existing methods of population estimation."Doctor of Philosoph
Application of Geographic Information Systems
The importance of Geographic Information Systems (GIS) can hardly be overemphasized in todayâs academic and professional arena. More professionals and academics have been using GIS than ever â urban & regional planners, civil engineers, geographers, spatial economists, sociologists, environmental scientists, criminal justice professionals, political scientists, and alike. As such, it is extremely important to understand the theories and applications of GIS in our teaching, professional work, and research. âThe Application of Geographic Information Systemsâ presents research findings that explain GISâs applications in different subfields of social sciences. With several case studies conducted in different parts of the world, the book blends together the theories of GIS and their practical implementations in different conditions. It deals with GISâs application in the broad spectrum of geospatial analysis and modeling, water resources analysis, land use analysis, infrastructure network analysis like transportation and water distribution network, and such. The book is expected to be a useful source of knowledge to the users of GIS who envision its applications in their teaching and research. This easy-to-understand book is surely not the end in itself but a little contribution to toward our understanding of the rich and wonderful subject of GIS
Socio-spatial analysis of small-area need and accessibility of Primary Healthcare Services in Nigeria: A sequential mixed methods study
Ph. D. Thesis.Accessibility of primary healthcare (PHC) services is crucial for maintaining the good health of
a population. Not only is health(care) associated with quality of life and socioeconomic
productivity, systematic variations in healthcare accessibility are matters of social justice.
Consequently, the overall goal of this project is to comprehensively analyze and explain smallarea need and accessibility of PHC services in Nigeria through a case study of Kogi State, with
a view to making policy-relevant recommendations. To this end, both quantitative and
qualitative methods are synthesized in an âexplanatory sequential mixed methods research
designâ, which also features innovative data exploitations. This entails a synergy of:
Automated Zone Design method, Spatial Microsimulation Modelling, and Generalized TwoStep Floating Catchment Area method for quantitative analysis as well as qualitative
framework thematic analysis, to obtain research findings that are more robust than existing
studies. In this way, genuine small-area variations in PHC need and accessibility are revealed
and explicated, including extreme Medically Underserved Areas (eMUAs). Urban areas are
more accessible than rural areas, as expected. Of senatorial districts, Kogi Central has the best
healthcare accessibility because of its topography. Furthermore, these variations are
mediated by the extant sub-optimal zoning system in Nigeria, which is a product of
problematic historical political processes. Not only are eMUAs both very remote and rural,
they also lack basic social amenities. Hence, it is not surprising that research participants
expressed a myriad of dire disincentives in meeting their PHC needs. These difficulties can be
mitigated by improving the quality of road infrastructure and ensuring an optimal socio-spatial
configuration of PHC services. Broad mechanisms of social exclusion are also implicated in
causing access-related disutility of PHC. It is therefore crucial that holistic interventions to
alleviate social exclusion are enacted, since previous efforts at addressing only proximal
concerns of PHC accessibility have proven unsuccessful.
Keywords: Primary Healthcare Needs, Spatial Accessibility, Mixed Methods Research,
Automated Zone Design, Spatial Microsimulation, Small-Area Variations.Newcastle University Overseas Research
Scholarship (NUORS), Research Excellence Academy of the Humanities and Social
Science Faculty (HaSS RE
Proceedings of the GIS Research UK 18th Annual Conference GISRUK 2010
This volume holds the papers from the 18th annual GIS Research UK (GISRUK). This year the conference, hosted at University College London (UCL), from Wednesday 14 to Friday 16 April 2010. The conference covered the areas of core geographic information science research as well as applications domains such as crime and health and technological developments in LBS and the geoweb.
UCLâs research mission as a global university is based around a series of Grand Challenges that affect us all, and these were accommodated in GISRUK 2010.
The overarching theme this year was âGlobal Challengesâ, with specific focus on the following themes:
* Crime and Place
* Environmental Change
* Intelligent Transport
* Public Health and Epidemiology
* Simulation and Modelling
* London as a global city
* The geoweb and neo-geography
* Open GIS and Volunteered Geographic Information
* Human-Computer Interaction and GIS
Traditionally, GISRUK has provided a platform for early career researchers as well as those with a significant track record of achievement in the area. As such, the conference provides a welcome blend of innovative thinking and mature reflection. GISRUK is the premier academic GIS conference in the UK and we are keen to maintain its outstanding record of achievement in developing GIS in the UK and beyond
Global flood model assessment and flood risk evaluation
Floods are the most frequent and damaging natural hazard globally. To adequately prepare for floods it is essential to know where they will occur and what their impacts will be. This can be done by developing a flood model. Traditionally, these models have been local in scale, limited to areas with the necessary expertise and data to develop a flood model. However, the last decade has seen the proliferation of several global flood models, which use global datasets and automated approaches to map flood hazard globally. When combined with global datasets of exposure and vulnerability, they can be used to assess global flood risk. The development of these global flood risk datasets marks a potential paradigm shift in flood risk analysis from the traditional âad hocâ approach to global datasets which can be used to assess flood risk anywhere in the world. Despite this, these global flood risk datasets still need significant evaluation to understand the limits of their effective application.
This thesis furthers the evaluation and explores the potential applications of global flood risk datasets. The current state of global flood risk modelling is reviewed, highlighting the different models, their history, structure, and application. The models are then collectively validated for the first time against observed flood events, demonstrating the skill of some models and identifying model characteristics which influence performance. The impact of river size thresholds, a key difference identified between the models, are quantified by calculating flood exposure to different sized rivers globally. Both the chosen river size thresholds and the global population maps used to calculate exposure are found to have a significant impact on flood exposure estimates. The use of global flood risk data is then explored nationally as global datasets of hazard, exposure, and vulnerability are evaluated for flood risk management in five countries. While some global datasets are found to be of potential use, there is still significant uncertainty in their national flood risk estimates and potential issues are identified related to the capacity there is to use them nationally
Geodetic infrastructure of Serbia
Geodetic reference systems and their realization at the territory of Serbia have been created and maintained since the end of 19th century. Until mid-80s a series of reference geodetic networks were established: trigonometric networks in four orders, two levelling networks of high accuracybut also a series of gravimetric networks. In the following period of 20 years, there were not any organized worksaiming to maintenance of existing networks and creating new ones. In 1996, works started again on developing a new geodetic infrastructure in the form of realizing: a passive geodetic network, a network of permanent stations (AGROS â the active geodetic reference network of Serbia) as well as basic gravimetric networks. In this paperwork, a short review of works aiming to establish and use said networks is given but also a series of suggestions for a future development of geodetic infrastructure of Serbia