Search

This study investigates households’ car ownership decisions in response to changes in vehicle quota control and transport infrastructure in Singapore. Unlike previous cross-sectional studies, we calibrate a dynamic car ownership model with a pseudo panel constructed from repeated cross-sectional travel surveys, controlling for the persistence of car ownership and unobserved heterogeneity. We find that the tightening of vehicle quota control and improved rail transit accessibility have reduced households’ desire to purchase cars. The long-run effect of these two policies is larger than their short-run effect due to the existence of true state dependence. The impact of expressway-network expansion is insignificant.

There is a growing use of digital and visualisation technologies in the documentation and preservation of cultural heritage sites. Using the Tampines Chinese Temple in Singapore as a case study, this paper presents a detailed methodological framework to create virtual tours for the preservation of both the physical built environment and intangible historical and sociocultural elements within the space of cultural heritage sites. Tangible data used in the creation of the virtual tour produced for the temple comprise spherical images collected via a 360° camera and two-dimensional (2D) high-resolution images obtained via a digital single-lens reflex camera. The tour also showcases intangible aspects of the temples cultural heritage, derived from references made to multiple sources, namely interviews with personnel involved in the management of heritage sites (e.g. the temple secretary) as well as historical archives (e.g. National Archives of Singapore and publications produced by the temple). In so doing, this paper promotes the importance of incorporating intangible elements of cultural heritage sites into a unified interface. This method is advantageous as the relatively low pricing of the chosen software, and the use of a 360° camera and digital single-lens reflex camera enhances accessibility for heritage practitioners and facilitate future applications.

This study used remote sensing imagery to characterize land use/cover patterns and to derive land surface temperature (LST) of Greater Yangon, the largest urban agglomeration in Myanmar, to provide insights into the association between land use/cover and seasonal, daytime, and nighttime LST change. Analysis of Landsat images from 1987 to 2015 showed urban expansion radiating from the city center and along prominent rivers, with major increases in built-up land (6.4%) and grassland (10.1%) and consequent decline in agricultural land (17%). Examination of MODIS LST showed that agricultural land was warmer than the city core during daytime in hot seasons, while in cold seasons, the city core was warmer than its rural surroundings during both daytime and nighttime. Correlation analysis revealed stronger association between built-up land and nighttime LST from 2000 to 2015, suggesting an increased surface urban heat island effect. Furthermore, this study highlighted two main differences from prior work on the influences of land use/cover on LST. First, the predominant land use/cover type that had great overall impact on LST was agricultural land, marked by its statistically significant correlation coefficients across all time periods of analysis. Such finding emphasized the influence of agriculture and related practices on the atmosphere and climate system. Second, the temporal analysis of LST highlighted a stronger and more complicated role water played because of its negative correlations with daytime LST and positive correlations with nighttime LST. The findings of this study underscored more complex effects of land use/cover on the spatial and temporal variations of LST in Yangon, compared to prior work that generally reported high LST in the urban areas. These insights improve the understanding of the land change consequences on the temporal dynamics of LST and can support sustainable land use planning for the better well-being of the inhabitants in Greater Yangon.

Using geographic information systems and digital elevation data, we investigate the hypothesis that the imperial Chinese state manipulated provincial borders to weaken the autonomy of Chinese regions. We find that China's present-day provincial borders, whose origin can be traced back to the thirteenth century, are highly misaligned with respect to physiographic features along China's North-South political fault line. Elsewhere, in regions that historically did not pose a fundamental threat to central authority, the degrees of misalignment are considerably lower. We interpret these findings as evidence of strategic manipulation of provincial boundaries. Our findings cast light on the spatial distribution of boundary misalignment and help identify the areas where the socioeconomic ramifications of misalignment—such as recurring cross-border pollution and inter-community disputes—are likely to be present.

In the process of rapid urbanization, the decline in ecosystems' physical supply value is a direct result of the increasing demands of human development. The ecosystem services value combined with supply and demand factors can be used to obtain the ecosystem services scarcity value (ESSV). These ecosystems with larger ESSVs warrant increased protection, or at the very least a development plan to ensure a balance between their continued existence and human usage. However, urbanization and other developmental effects have often caused the ESSV of those regions to be disregarded, which produces an imbalance in the ecosystem. This paper evaluated the spatial differentiation of ESSV based on heterogeneous units in the Yuebei region, China. Then, a spatial response analysis of the ESSV to urbanization according to the spatial correlation model and Getis-Ord Gi* was conducted. The results showed that the ecosystem service physical supply value declined due to urban sprawl in 1990–2015, but the ESSV increased sharply during the same time with its acceleration being particularly strong after 2000. Areas with higher ESSV were concentrated in the northern region due to a higher prevalence of woodland. Urbanization accelerated significantly after 2000, and it is found that similar tendencies of ESSV and urbanization occurred over the same period. Surprisingly, the ESSV was negatively correlated with urbanization in local regions, and their interaction continued to increase over time. The spatial hotspot map of the ESSV and urbanization also formed an opposite pattern. In addition, the grid number of High-Low and Low-High types is more than half of the total number of aggregated grids. According to the results, understanding the variation in the ESSV clearly due to urbanization and identifying their interaction in local regions can provide a more specific direction for future resource adjustment and ecosystem service improvements.

The unprecedented rate of urbanization in China since 1978 has profoundly impacted its landscape and threatened ecosystem sustainability. To devise effective sustainable development policy, it is imperative to quantify the relationships between urbanization and ecosystem services in a spatially explicit manner. For this purpose, ecosystem service value (ESV) is commonly adopted, especially, in evaluating the changes of ecosystem services in terms of physical supply capacities. Existing research efforts, however, rarely considered the scarcity caused by the supply-demand dynamics, which was incorporated into ESV, or succinctly, ecosystem service scarcity value (ESSV). In addition, they tended to focus on the local and regional levels, leaving unattended the national level analysis that carries important policy implications. This paper fills this gap by quantifying first the spatiotemporal patterns of ESSV and their changes at the province level for China, and second the spatial variations of the relationship between urbanization and ecosystem services employing geographically weighted regression (GWR) model. The results showed that the ESSV was highest in the southeast and lowest in the northwest in China and the total ESSV in all provinces trended upward from 1990 to 2015. The population growth, urban land expansion, and economic growth due to urbanization were clearly higher in the eastern coastal areas and the areas along the Yangtze River than in other regions. The ESSV and gross domestic product growth of developed regions both shared the same growth trend over time; in particular developed regions saw a sharper increase than less developed regions. This showed a positive correlation between the ESSV of a region and its economic situation. The changes of spatial impacts of urbanization on ESSV were mainly driven by regional development policy, which was confirmed by the results from GWR. Therefore, promoting a holistic view of land use functions with socioeconomic activities, such as maintaining a balanced urban development, implementing ecological compensation and strengthening regional cooperation across administrative boundaries, is encouraged to reconcile the conflict between urbanization and ecosystem management.

Opisthorchis viverrini (Ov) is one of the most important human parasitic diseases in Southeast Asia. Although the concept of connectivity is widely used to comprehend disease dispersal, knowledge of the influences of landscape connectivity on Ov transmission is still rudimentary. This study aimed to investigate the role of landscape connectivity in Ov transmission between the human and the first intermediate snail hosts. Fieldwork was conducted in three villages respectively in Kamalasai District, Kalasin Province, Phu Wiang District, Khon Kaen Province, and Nong Saeng District, Udon Thani Province. Bithynia snails were collected to examine parasitic infections, water samples were analyzed for fecal contamination, and locations of septic tanks and connections between habitat patches with observable water movement were surveyed. Euclidean distance, topological link and distance, and graph measures were employed to quantify the connectivity between human and snail habitats. The findings showed that snail patches with higher fecal contents were generally located nearer to septic tanks. The statistically significant results for the topological link and distance measures highlighted the importance of water in functionally facilitating Ov transmission. Graph measures revealed differences in landscape connectivity across the sites. The site with the largest landscape component size and the most mutually connected snail patches coincided with the presence of Ov parasite, reinforcing its higher risk for human to snail transmission. The site with the dissected landscape structure potentially limited the transmission. This study underscored the potential effect of landscape connectivity on Ov transmission, contributing to the understanding of the spatial variation of Ov infection risk.

This study investigated the potential global distributional shifts of poikilothermic invasive crop pest species associated with climate change, aiming to understand if their overall global distributions will expand or contract, and how the species distributions will vary across different regions. An ecological niche modelling analysis was conducted for 76 species. The potential distributional changes of the species in 2050 and 2070 were scrutinized for two climate change scenarios, which were further examined across different temperature and precipitation ranges. Results showed that averages of the mean probabilities of presence of the 76 crop pest species were predicted to increase. Higher species turnovers were predicted mostly to occur in areas with increasing predicted species richness. Lower species turnovers, however, were predicted mostly to occur in areas with decreasing predicted species richness. Species richness increases were predicted to occur more often in currently lower temperature (annual mean temperature approximately

Increasing CO2 emissions from the transport sector have raised substantial concerns among researchers and policy makers. This research examines the impact of the built environment on individual transport emissions through two mediate variables, vehicle usage and vehicle type choice, within a structural equation modelling (SEM) framework. We find that new-urbanism-type built environment characteristics, including high density, mixed land use, good connectivity, and easy access to public transport systems help reduce transport CO2 emissions. Such mitigating effect is achieved largely through the reduced vehicle miles travelled (VMT) and is enhanced slightly by the more efficient vehicles owned by individuals living in denser and more diverse neighborhoods, all else being equal. Our research findings provide some new evidence that supports land use policies as an effective strategy to reduce transport CO2 emissions.

This paper illustrates the detailed design and implementation strategy of a high-performance, parallel agent-based Schelling model. There are four key issues to implement a parallel agent-based Schelling model, i.e., the ability to handle (1) the complexity of real data processing; (2) spatial data decomposition; (3) the preference and tolerance rates for multiple ethnic groups; and (4) the communication between agents. A new parallel algorithm that addresses these issues while retaining the fundamental concepts of the original sequential Schelling model was built. The parallel Schelling model was applied to the County of San Diego’s one million household agents and one million housing unit agents using land use data and 2000 Decennial Census data. Experiments using varying numbers of CPU cores demonstrate that the computational performance of the parallel Schelling model positively correlates with increased numbers of CPU cores. This paper focuses on the implementation of a parallel agent-based Schelling model. The Schelling model is parallelized to illustrate how high-performance computing can elicit better understanding of real-world geospatial phenomena. By leveraging distributed computing resources in geospatial cyberinfrastructure, the parallel Schelling model has the potential to become a crucial component in spatial decision support systems and to help policy makers understand the key trends in urban population, urban growth, and residential segregation.

Qualitative locations describe the locations of spatial objects by relating them to a reference frame with qualitative relations. Existing models concerned with regional partitions are mainly topology-based and do not consider the effects of scale changes on locations. This study develops a direction-based multi-scale qualitative location (DMQL) model to fill this gap. First, a cell partition is defined by extending the borders of the minimum bounding rectangles of the regions in a regional partition. Relating spatial objects to all regions by a set of directions is equal to representing the objects as a set of cells in a cell partition. Second, due to the multiple cell representations of spatial objects and the changes in direction relations across scales, some approaches are presented to derive the direction changes between regions in different frames, between spatial objects and regions, and between spatial objects at different scales. Third, the location and relation consistencies of qualitative locations are evaluated based on the cell representations of spatial objects at multiple scales through a case study. The results indicate that the DMQL model can locate objects more precisely than the topology-based models.

This paper analyses the available typhoon data for the western North Pacific between 1951 and 2008, archived by the Regional Specialized Meteorological Centre in Tokyo. GIS methodology was used to extract key spatial characteristics of 1533 individual typhoons, including origin and destination coordinates and intervening positions, in order to investigate the nature of typhoon-track sinuosity over the past six decades. Temporal analysis illustrates strong inter-annual variability as the principal feature of sinuosity change, although not necessarily driven by ENSO, and allows anomalous years (e.g. 1991, 1995 and 1999) and the present quiescent period to be identified. Yet, typhoon-track sinuosity has not experienced any long-term trend during the study period, implying the limited effects (so far) of climate change on this aspect of typhoon behaviour. Spatial patterns in sinuosity are distinguished through track visualisation and zoning. UTM zones 49–51 (108–126°E) have a higher tendency to produce straighter-tracking typhoons, which make landfall in South East Asia. Nearly two thirds (64%) of typhoons following convoluted track shapes with high sinuosity values (sinuosity ≥2) originated within a 30° longitudinal band in the mid–eastern portion of the study area (UTM zones 54–58, 138–168°E). Temporal analysis reveals that later months of the NW Pacific typhoon season (September to December) are characterised by greater proportions of sinuous tracks. Quartile division of the positively-skewed sinuosity distribution enables the designation of typhoon tracks into four ordinally-named sinuosity categories: ‘straight’, ‘quasi-straight’, ‘curving’ and ‘sinuous’. This system facilitates the conceptualisation of track style and thereby improves on traditional binary groupings for track shape description.

One difficulty in sharing datasets between research projects and research teams is variation in the semantic content of the data expressed as differences in categorization. One step towards achieving semantic interoperability is to have means to measure the degree of semantic similarity between existing datasets and the target categorization of the new study. A variety of environmental and urban analyses use land use/land cover data to describe the natural environment. This paper focuses on measuring semantic similarity between categories in different land use/land cover classification systems. A modified feature-based approach is employed. Semantic components of a category are weighted to emphasize critical features in the categories definition. A case study is presented to demonstrate how semantic similarity is measured between target categories in a specific study and categories already in use in existing land use/land cover classification systems.