Jinn-Guey Lay

Higher temperature and urbanization affect the spatial patterns of dengue fever transmission in subtropical Taiwan

Our study conducted spatial analysis to examine how temperature and other environmental factors might affect dengue fever distributions, and to forecast areas with potential risk for dengue fever endemics with predicted climatic change in Taiwan. Geographic information system (GIS) was used to demonstrate the spatial patterns of all studied variables across 356 townships. Relationships between cumulative incidence of dengue fever, climatic and non-climatic factors were explored. Numbers of months with average temperature higher than 18 degrees C per year and degree of urbanization were found to be associated with increasing risk of dengue fever incidence at township level. With every 1 degrees C increase of monthly average temperature, the total population at risk for dengue fever transmission would increase by 1.95 times (from 3,966,173 to 7,748,267). A highly-suggested warmer trend, with a statistical model, across the Taiwan Island is predicted to result in a sizable increase in population and geographical areas at higher risk for dengue fever epidemics.

An Experiment to Model Spatial Diffusion Process with Nearest Neighbor Analysis and Regression Estimation

Spatial diffusion processes can be seen in many geographic phenomena that spread or migrate across space and over time. Studies of these processes were mostly done with verbal description until Hagerstrand 1966 started to approach it with quantitative models. A variety of attempts were made to continue this effort, but only with various degrees of success. Recognizing the critical role that distances between geographic objects or events play in a spatial diffusion process, we experimented with a new approach that uses these distances to detect and distinguish different types of spatial diffusion processes. Our approach is a two-step process that first calculates nearest neighbor ratios in a point process at each time step and then applies regression curve estimation to observe how these ratios change over time. We first report the results from applying this method to three spatio-temporal data sets which show the feasibility of our approach. We then report results of randomly simulated spatial diffusion processes to see if our approach is effective for the purpose of distinguishing different types of spatial diffusion processes. With only extreme cases as exceptions, our experiment found that using estimated regression curves of nearest neighbor ratios over time is usable in classifying spatial diffusion processes to either contagious/expansion or hierarchical/relocation diffusion processes.

Geographic Reality Versus Imagination in Taiwan’s Historical Maps

Abstract During the past 400 years, Taiwan has experienced the dominance of various political regimes, which allowed the development of a diversity of cartographic styles for academic comparison. A detailed analysis of historical maps across centuries demonstrates that this contested island has been illustrated with a blending of reality, misconception and imagination. This paper narrates how maps reveal political rulers’ conscious and unconscious perceptions of this island. We call attention to the abundant cartographic materials in existence and suggest that they can be fascinating materials for the study of the contested colonial histories of this island in various disciplines.

Exploring non-stationarity of local mechanism of crime events with spatial-temporal weighted regression

For a more effective understanding of dynamic of mechanism and cluster of local crime, this study uses kernel density to reveal abilities of detecting space-time hotspots in the context of time geography. Since spatial data are correlated in nature, geographically weighted regression (GWR) has been proven as an effective tool to address the spatial non-stationarity. Thus, this study adopts temporal variants to detect the spatial-temporal non-stationarity of structural measures simultaneously. Using a geocoded criminal dataset of residential burglary in Da-an District of Taipei City from 1999 to 2007, we examine the proposed framework allowing interactively 3-D visualization of crime hotspots by volume rendering. We also reveal the non-stationarity of estimations of social structural measures by a variant weighted regression approach. Emphasizing the supplementary aspect of our embedded framework, we conclude that 3-D spatial-temporal data analysis and the variant of geographically weighted regression could identify the space-time hotspots as well as extract and interpret the spatial-temporal non-stationarity of mechanism of residential burglary.

Spatial-linguistic reasoning in LEI

In LEI, the Locality and Elevation Interpreter, lingusitic and geometric reasoning are joined to resolve natural language representations of locations as geodetic coordinates. The system uses the PAU (Parser and Understander) system to translate locality descriptions into semantic relations. The relations are then disambiguated by instantiation from USGS data bases. The projects goal is to replace operator intervention in locality interpretation.

Beyond technology: Japanese colonial mapping of water estates in Taiwan from 1901 to 1921

ABSTRACT Irrigation systems in Taiwan were originally developed as private property and first put under strict government control during the Japanese colonial rule from 1895 to 1945. To understand how the Japanese introduced mapping to facilitate their early governance on irrigation systems developed by locals, this study explored the irrigation reform implemented in 1901 and its influence on the emergence of two types of irrigation mapping. One is entitled ‘Irrigation Register Maps’ and the other ‘Irrigation Application Maps’. By exploring unpublished papers in the Archives of the Government-General of Taiwan (Taiwan Sotokufu), the manuscripts of these two types of irrigation map were examined in terms of their mapping initiatives, rationales and techniques. While ‘Irrigation Register Maps’ were produced by the colonial government to illustrate the existing water ownership with public interest, ‘Irrigation Application Maps’ were written by the local residents in order to claim new water ownership with private interest. In addition to depicting irrigation routes, both types of mapping were integrated with rich textual information about water ownership and management frameworks. To conclude, this paper argues that Japanese colonial mapping was an in-depth activity about re-presenting and reshaping local cultures, instead of merely reproducing Western technologies.

Colonial Powers and Geographic Naming: A Case Study of Orchid Island (Lanyu), Taiwan

This paper discusses how geographical naming was applied by various colonial powers during their initial exploration and mapping of an indigenous island. In a case study of Orchid Island, we compare the cartographic works performed by three colonial powers during the seventeenth—nineteenth centuries of Taiwan, namely, the Dutch East India Company, the Ching Empire and the Japanese Empire. Instead of documenting the toponymic change, our target is to uncover the strategies of place-naming in accordance with the underlying exploration purposes and cartographic perspectives. Early Dutch and Chinese explorers were found to behave in a similar way by denoting Orchid Island with ambiguous names derived from external societies, simply illustrating a geo-referenced dot on the general maps of Taiwan. On the other hand, the Japanese explorers strived to compile the first large-scale map of Orchid Island with names identifiable with local geography. It should be noted that both political and ethnographic interests were involved with the Japanese mapping of Orchid Island in the late 1890s, which resulted in two versions of toponyms, one is information-driven and the other based on local knowledge. To conclude, heterogeneous ways to deal with indigenous place names were found to reflect different colonial interests and cartographers’ interactions with local society.

Mapping Taiwan from an alternative angle

Abstract Please click here to download the map associated with this article. The leitmotif of creating “Taiwans East Asian Neighbors” lies in providing alternative perspectives of observing Taiwan that are absent in traditional maps. Instead of using a conventional Mercator projection, leading to serious distortions of territories at the mid and high latitudes, this map uses an oblique Mercator projection and tactful selection of standard lines to present a precise image of Taiwan and its surrounding countries of the East Asian island arcs. The novelty of this cartographic product has stirred debates from various corners of Taiwan society. These debates reflect the success of this map because it has achieved the aim of stimulating plural perspectives of observing and understanding Taiwan. “Taiwans East Asian Neighbors” manifests well the potential geopolitical impacts of cartography on a society.