Abstract: This research is motivated by the increasing threat of urban heat waves that are likely worsened by pervasive global warming and urbanization. Different regions of the city including urban, borderland and rural area will experience different levels of heat health risk. In this paper, we propose an improved approach to quantitatively assess Beijing’s heat health risk based on three factors from hazard, vulnerability and especially environment which is considered as an independent factor because different land use/cover types have different influence on ambient air temperatures under the Urban Heat Island effect. 继续阅读“Assessing Heat Health Risk for Sustainability in Beijing’s Urban Heat Island”
Abstract: This article focuses on the image fusion of high-resolution panchromatic and multispectral images. We propose a new image fusion method based on a Hue-Saturation-Value (HSV) color space model and bidimensional empirical mode decomposition (BEMD), by integrating high-frequency component of panchromatic image into multispectral image and optimizing the BEMD in decreasing sifting time, simplifying extrema point locating and more efficient interpolation. This new method has been tested with a panchromatic image (SPOT, 10-m resolution) and a multispectral image (TM, 28-m resolution). 继续阅读“A Bidimensional Empirical Mode Decomposition Method for Fusion of Multispectral and Panchromatic Remote Sensing Images”
Abstract: The quality of dynamic map symbols plays an important role in the representation of spatial-temporal changes. This paper reports an investigation into the quality of dynamic symbols. To assess the quality of such symbols, a set of traffic flow data is used for the production of different kinds of dynamic maps, with focus on four variables, i.e. size, color, frame rate and display format. Two quantitative measures are used for analysis, i.e. deviation and response time. A set of traffic data is used for the production of dynamic maps for evaluation. The experimental results show that the size is more efficient and more effective than color for dynamic maps with the same frame rate and display format. 继续阅读“Effectiveness and efficiency of map symbols for dynamic geographic information visualization”
Abstract: This article deals with the graphic simplification of a network by schematization. A new method employing a stroke-based and progressive strategy is proposed to generate schematic network maps. This method treats a stroke (which is a long line with segments concatenated together) as a basic unit for the implementation. 继续阅读“A stroke-based method for automated generation of schematic network maps”
Abstract: A metro map is usually optimized for the readability of connections and transportation networks structure. In order to assure good readability and meet aesthetic considerations, a set of principles for good metro map layout are proposed. According to these principles, a new methodology based on dynamic segmentation is presented to produce the metro maps automatically. Firstly, routes are constructed according to the line attribute similarity and geometry continuity. Then a set of cartographic generalization methods about the shape, angle, length, and topology are presented for these routes. This method is validated by Beijing metro plan map. From the experiment results, it can be concluded that this new method is more effective than the static segmentation method to produce metro maps with better readability for route plans. 继续阅读“Automatic generalization of metro maps based on dynamic segmentation”
Abstract: Multiple constraints for schematic road network map cartographic design are analyzed and summarized. Based on this, a set of quantitative criteria are set up and a new road network generalization method including progressive selection and displacement is proposed. Furthermore, topological checking methods for road networks are researched. Based on these constraints, the points in a road network are classified, and a satisfactory and effective schematic map is designed in a concrete experiment while maintaining topological consistency of the road network between the original and the schematic map.