Spatial and temporal knowledge representation

Knowledge Representation (KR) originated as a discipline within Artificial Intelligence, and is concerned with the representation of knowledge in symbolic form so that it can be stored and manipulated on a computer. This article surveys that part of KR that is concerned with the representation of space and time, with particular reference to the use of such representations in geographical information science.

Remote sensing and GIS based determination of groundwater dependent ecosystems in the Western Cape, South Africa

Finding the location of groundwater dependent ecosystems (GDEs) is important in determining the extent of restrictions that need to be placed upon the abstraction of groundwater. Remote sensing was combined with geographical information system (GIS) modelling to produce a GDE probability rating map for the Sandveld region, South Africa. Landsat TM imagery identified the areas indicating the probable presence of GDEs and GIS assisted in their delineation. Three GIS models were generated: a GIS model predicting landscape wetness potential (LWP model) based on terrain morphological features; the LWP model was modified to highlight groundwater generated landscape wetness potential (the resulting GglWP model); and a groundwater elevation model was interpolated, combining groundwater level measurements in boreholes in the region with digital elevation model data. Biomass indicators generated from Landsat were classified and combined with the GIS models, followed by field verification of riverine and wetland GDEs. The LWP model provided the most accurate results of the three models tested for GDEs in this region.

Predicting environmental conditions to minimise salt damage at the Tower of London: a comparison of two approaches

The paper compares the results of two studies of salt damage at the Wakefield Tower, Tower of London. The first, in 1993, was based on semi-quantitative salt analysis and hygroscopicity measurements. The second was based on quantitative analysis and a thermodynamic model, ECOS. Both studies aimed to predict environmental conditions that would minimise salt damage to the interior stonework. Their predictions are markedly different, and this paper examines the reasons for the differences. It is shown that hygroscopicity alone is not a reliable indicator of crystallisation from mixed salt solutions.

Erosion rates on subalpine paleosurfaces in the western Mediterranean by in-situ <Superscript>10</Superscript>Be concentrations in granites: implications for surface processes and long-term landscape evolution in Corsica (France)

A study of erosion rates by in-situ ¹⁰Be concentrations in granites of Miocene high-elevation paleosurfaces in Corsica indicates maximum erosion rates between 8 and 24 mm/kyear. The regional distribution of measured erosion rates indicates that the local climatic conditions, namely precipitation, the petrographic composition of granites, and the degree of brittle deformation govern erosion rates. Chemical erosion dominates even at elevations around 2,000 m in presently subalpine climate conditions. Field evidence indicates that erosion operates by continuous dissolution and/or disintegration to grains (grusification). The erosion rates are relatively high with respect to the preservation of inferred Early Miocene landscapes. We infer temporal burial in the Middle Miocene and significantly lower erosion rates in the Neogene until ∼3 Ma to explain the preservation of paleosurfaces, in line with fission track data. Valley incision rates that are a magnitude higher than erosion rates on summit surfaces result in relief enhancement and long-term isostatic surface uplift. On the other hand, widening and deepening of valleys by cyclic glaciation progressively destroys the summit surface relics.

Assessment of suffosion-related hazards in karst areas using GIS technology

This paper describes an application of the geographic information system (GIS) technology to a ground stability assessment in the karst area of Dzerzhinsk, Russia. In the stability analysis, the groundwater level changes in the karst aquifer could cause suffosion sinkholes when the gravitational force was greater than the soil strength. The GIS technology was used to combine various data and to delineate the zones of potential gravitational collapse and suffosion collapse in the area.

Tornado shelters and the manufactured home parks market

Manufactured or mobile homes represent a fast growing portion of the housing market but are particularly vulnerable to tornadoes. In the US over 40% of tornado fatalities occur in mobile homes even though they comprise about 8% of US housing units. We examine the market for tornado shelters in manufactured home parks in Oklahoma. Almost 60% of parks in the state have shelters, with 90% of the shelters underground. Parks with shelters are not concentrated in urban areas but spread across the state, with parks with shelters in 32 counties. We find that rents for lots in parks with shelters are 5–8% higher, which generates sufficient revenue to approximately pay for shelters, but the point estimate is statistically significant in only one specification.

Mapping flood pressure points: assessing vulnerability of the UK Fire Service to flooding

A vulnerability index for the Fire Service in the UK has been designed to identify vulnerable locations during episodes of severe floods. Taking recent case studies with the UK Fire Service, the patterns of vulnerability, in terms of demand on time and resources, can be explained by investigating the environmental causes and their interaction with the adaptive capacity of the response agencies.

Alternative technologies for rural areas–what about the ‘alternative’ dimension of Wi-Fi?

Summary  The question of alternative technologies for high-speed Internet access lies at the heart of rural development problems. In this paper, we focus on one of those technologies, the system combining satellite technologies and Wi-Fi. Based on an empirical study carried out in three rural areas, we analyze the dynamics of the use and appropriation of that technology by the companies and organizations participating in the experiment. Considered both from a technical and social standpoint, the technology ‘in use’ appears here in its structuring dimensions.

Space Physics Interactive Data Resource—SPIDR

SPIDR (Space Physics Interactive Data Resource) is a standard data source for solar-terrestrial physics, functioning within the framework of the ICSU World Data Centers. It is a distributed database and application server network, built to select, visualize and model historical space weather data distributed across the Internet. SPIDR can work as a fully-functional web-application (portal) or as a grid of web-services, providing functions for other applications to access its data holdings.

Peace Parks and jaguar trails: transboundary conservation in a globalizing world

An increasingly utilized strategy for expanding conservation in the developing world has been the promotion of protected areas that supersede national borders. Alternatively known as transfrontier biosphere reserves, transfrontier or transboundary conservation areas, or Peace Parks, these protected areas are aggressively advanced by conservation agencies for their purported ecological and economic benefits. This article provides a comparative assessment of two case studies to understand the various impacts of transboundary conservation. The Great Limpopo Transfrontier Park, which unites protected areas in South Africa, Mozambique and Zimbabwe, is contrasted with efforts to protect jaguars along the United States–Mexico border. We argue that while these cases are promising for the purposes of biodiversity protection, they demonstrate that transboundary conservation can minimize political context, contributes to the hegemony of international conservation agendas, and remains closely linked to economic neoliberalism and decentralization in the developing world.

Evaluating the influence of mixture composition on the kinetics of salt damage in wall paintings using time lapse video imaging with direct data annotation

This paper presents an examination of the timescale of phase transition behaviour of a series of salts known to cause damage to wall paintings and other cultural property. The rate of deliquescence and crystallisation of single salts (nitromagnesite and halite) under different RH regimes, and the extent to which this was affected when mixed with other salts (niter, nitratite and gypsum), was investigated. The study was conducted using simple conventional techniques (mass measurements over time) and also using an innovative new method: timelapse video imaging with online data annotation. The results demonstrate the synergy gained from combining video imaging with environmental data in reference to time in the study of salt phase changes: where it revealed new information concerning the kinetics of deliquescence and crystallisation. The implications of these results for the implementation of environmental control measures within historic buildings are discussed.

Global airline networks and nodal regions

Transportation infrastructure has always played an important role in the economic fate of regions. In particular, airline networks have dramatically decreased the geographic and temporal constraints of moving people, goods and information; all of which are increasingly crucial inputs for the information economy. As a result, regions have become more concerned with both the quantity and quality of airline connections. The purpose of this paper is to examine the emerging global hierarchy of airline network connectivity. Using a proprietary database of nearly 900 airline carrier schedules from 2006, we examine regional connectivity between 4,650 worldwide origins and destinations. Through the use of network analysis and graph theoretical techniques, results indicate an increasingly complex web of nodal hierarchies in North America, Europe and Asia.

Geographic media literacy: an introduction

In a media saturated world of globalization, information flow and knowledge economies, an interesting paradox exists: geographic literacy appears to be on the decline while geographic information is on the rise. In this introduction to a collection of essays on geographies of the media, we explore this paradox and use Baudrillard’s (1994) work on Simulacra and Simulation to argue that increased mediated information does not produce more meaning, but rather leads to a catastrophe of meaning and the medium. Drawing from McLuhan’s axiom, “the medium is the message,” we posit that with more mediated information there is less meaningful information and as such we need to address geographic media literacy as a primary mode through which to address geographic literacy.

Melt inclusion formation mechanisms and compositional effects in high-An feldspar and high-Fo olivine in anhydrous mafic silicate liquids

Important aspects of melt inclusion formation and potential compositions effects have been addressed through a series of experiments using anorthite/fosterite saturated anhydrous mafic liquids. Experimental charges were cooled from 1,300 to 1,230 and 1,210°C at rates of 1–10°/min followed by 0–24 h isothermal periods. Hopper and skeletal crystal morphologies with variable degrees of completeness developed during the cooling period. Planar overgrowth of these textures during isothermal periods led to the formation of inclusions, the majority of which formed after 6 h of isothermal run time. We suggest that the change in morphologies is related to a decrease in growth rates and changes in dominant growth mechanisms. In general, inclusion compositions were uniform and similar to the host glass, indicating that with the isothermal times required for most inclusions to form, a boundary layer was not entrapped that could be detected within the limits of our analyses.

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China’s container-related dynamics, 1990–2005

This study seeks to gauge how far China’s container-related dynamics between 1990 and 2005 fit into the wider perspective about transport and development within developing countries. In particular, attention is focussed on the role of specific modes to determine the extent of the penetration of containers within China. Before addressing these key issues extant models relating to an understanding of port and transport evolution in less-developed countries are recalled, synthesized and used as a base upon which an appropriate review of China’s case can be conducted. Applying them to China’s northern, central and southern port ranges not only helps assess the efficacy of these models but also highlights the contribution of individual modes.

The role of economic analysis in groundwater management in semi-arid regions: the case of Nigeria

The aim of this paper is to use an economic framework to derive decision making rules for river basin management with a focus on groundwater resources. Using an example from northern Nigeria, the paper provides an example of how decision making for sustainable water resources management may be facilitated by comparing net benefits and costs across a river basin. It is argued that economic tools can be used to assess the value of water resources in different uses, identify and analyze management scenarios, and provide decision rules for the sustainable use and management of surface and ground water resources in the region.

Sex offenders,housing and spatial restriction zones

Sex offenders are currently a major focus of crime control policies at the local, regional, state and federal levels throughout the United States. In part, the perceived threat of offender recidivism has motivated legislators to launch stringent community notification programs and to establish spatial restriction zones (SRZs) around schools, daycare facilities and public parks. The purpose of these restriction zones is to help protect children and minimize their exposure to convicted sex offenders living in the community. In addition to the concern that the implementation of SRZs dramatically reduces viable housing options for registered sex offenders, there are concerns that offenders will be forced to reside in socially disorganized areas that may encourage recidivism. The purpose of this paper is to explore the demographic and socioeconomic differences between areas inside and outside SRZs. Implications of these results for sex offender policies are discussed.

A commented translation of the paper by C.W. Correns and W. Steinborn on crystallization pressure

Crystallization of salts is recognized to be a major factor of the degradation of porous materials such as stone and concrete. On the theoretical side, there is now general acceptance about the thermodynamic origin of this phenomenon. However, on the experimental side, there are only scarce quantitative data. In this respect, the reference work par excellence is that of Correns (Discuss Faraday Soc 5:267–271, 1949) who shows a good correlation between calculated and measured crystallization pressures. However, concerns about both the thermodynamic derivation and the experimental conditions raise the question about why Correns could have obtained such a good correlation. This issue is discussed extensively in this paper which is organized as a commented translation of a former paper by Correns, co-authored by Steinborn, and that is much richer in experimental details.

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Experimental and theoretical study of the structural environment of magnesium in minerals and silicate glasses using X-ray absorption near-edge structure

X-ray absorption spectroscopy at the Mg K-edge is used to obtain information on magnesium environment in minerals, silicate and alumino-silicate glasses. First-principles XANES calculations are performed for minerals using a plane-wave density functional formalism with core-hole effects treated in a supercell approach. The good agreement obtained between experimental and theoretical spectra provides useful information to interpret the spectral features. With the help of calculation, the position of the first peak of XANES spectra is related to both coordination and polyhedron distortion changes. In alumino-silicate glasses, magnesium is found to be mainly 5-fold coordinated to oxygen whatever the aluminum saturation index value. In silicate glasses, magnesium coordination increases from 4 in Cs-, Rb- and K-bearing glasses to 5 in Na- and Li-bearing glasses but remains equal as the polymerization degree of the glass varies. The variation of the C feature (position and intensity) is strongly related to the alkali type providing information on the medium range order.

Implications of subsurface thermal–hydraulic–mechanical processes associated with glaciation on Shield flow system evolution and performance assessment

A deep geologic repository (DGR) situated on the Canadian Shield will be subject to long-term climate change that will markedly alter surface conditions as a result of glaciation and permafrost penetration. Systematic, two-dimensional and three-dimensional coupled thermal–hydraulic–mechanical finite-element simulations with varying degrees of coupling, including depth-dependent salinity (represented as a change in groundwater density) and temperature-dependent density and viscosity, were undertaken to address the implications of glaciation on groundwater flow system dynamics as it could affect DGR performance. The modelling domain consisted of a 1.6-km deep sub-regional scale (≈100 km²) fractured Shield flow system. Initial and transient thermal, hydraulic and mechanical boundary conditions were developed from two realizations of the University of Toronto Glacial Systems Model of the last Laurentide glaciation. Results indicate that during the glacial loading/unloading cycle, for this particular conceptual model, there is limited penetration of glacial meltwaters to depth and small residual anomalous hydraulic head. During glacial coverage, the mechanical factor of safety increases in the moderately fractured and sparsely fractured rock mass, but principal effective stress reorientation also occurs. Given the assumed nonglacial in situ state of stress and mechanical properties, the fracture zones were predicted to be less stable under glacial conditions.