共查询到20条相似文献，搜索用时 31 毫秒
1.
Eduardo Gomes 《The Cartographic journal》2017,54(2):157-162
Dot maps are one of the best ways to visualize absolute values in thematic cartography. Dots represent quantitative data on a map. Population is often used in this type of representation. This paper presents a population dot density map for the year 2011 on two scales: (1) for mainland Portugal, and (2) for the Lisbon and Oporto regions. We have used dots with constant values and sizes at the most detailed statistical level (i.e. statistical subsection) for localities with less than 5000 inhabitants, and proportional circles for localities with more than 5000 inhabitants. These two scales of analysis coupled with two cartographic representation techniques used on a single map allow for a clear reading of the distribution of population. 相似文献
2.
Tomasz Opach J. Korycka-Skorupa I. Karsznia T. Nowacki I. Gołębiowska J. K. Rød 《制图学和地理信息科学》2013,40(4):347-367
ABSTRACTProportional point symbols are commonly used in map displays. However, when such displays are zoomed out, the available map space shrinks and consequently symbols overlap and the display suffers from visual clutter. Therefore, solutions are needed to reduce visual clutter in zoomable map displays that contain proportional point symbols. The authors add to the body of knowledge through the investigation of the performance of three solutions: aggregation of unit areas, the displacement of overlapping symbols, and modified symbolization; four variations of modified symbolization are examined in detail. The original study begins with a consideration of the strengths and weaknesses of the solutions, with an emphasis on information loss. Thereafter, user sessions with 165 participants are arranged to gain empirical evidence of the performance of the solutions. The results reveal that although participants zoom out the map to zoom levels that implement visual clutter reduction techniques, they tend to zoom in the map and pan it to examine specific areas. Moreover, they willingly use the map with aggregated unit areas in cases when the solution facilitates task accomplishment. A certain amount of skepticism attaches to the solution that displaces overlapping symbols. 相似文献
3.
Scree Representation on Topographic Maps 总被引：1，自引：0，他引：1
none 《The Cartographic journal》2013,50(2):141-149
Abstract<title/>Scree patterns are an important element of mountain maps in Swiss style. The size and density of scree dots vary with the exposition towards a source of illumination, which makes the dots extremely labour intensive to map without specialized algorithms. This paper identifies design principles for the symbolisation of scree fields on mountain slopes and presents a digital method for the quick placement of dot symbols requiring only minimal interventions by a cartographer. When digitally produced scree is combined with a shaded relief and a rock drawing, the terrain appears as a continuous three-dimensional surface to the reader. The described method is implemented in Scree Painter, a specialized free open-source software application. Scree patterns produced with Scree Painter match the quality standards of manually generated scree representations. 相似文献
4.
《The Cartographic journal》2013,50(1):8-18
AbstractWe explore visual map abstraction for the generation of stylized renderings of 2D map data. We employ techniques that are centred around the concept of shape simplification and graph layout and that allow iterative abstraction of 2D maps. We use data from publicly available sources and show how we can iteratively generate aesthetic renditions of these maps. These renditions do not have the goal to allow for navigation tasks, but instead show the map data in a distorted manner. The techniques used to create these images apply simplification, abstraction/generalisation, and displacement operations to the map elements in varying orders and add stylistic shading to produce aesthetic renditions for print or electronic displays. The degree of abstraction/generalisation can be individually chosen and determines the characteristics of the distorted map: whether components retain their shape, degenerate, or are processed in a manner that the abstraction becomes the focus of the image rather than the underlying map data. The renditions can be further personalized by choosing shading and colours for this shading. Together, the presented techniques allow for playful and creative exploration of aesthetic renditions of 2D map data. 相似文献
5.
针对地图制图中色彩选择较为困难的问题,该文收集国内外优秀地图、地图集、著作等上成功的设色方案,提取大量地图色彩样本。利用核密度估计方法,分析各类地图的常用色域区间,作为地图配色时的基色调。根据大量的地图色彩样本,利用定量的数学方法以及数据挖掘方法,探索地图色域特征分布规律。最后以收集的人口地图和环保地图颜色样本为例进行实验分析,对比证明本文方法能够很好地缩小地图色域选择区间,方便制图者根据地图种类选择颜色。 相似文献
6.
《制图学和地理信息科学》2013,40(4):196-205
Visualization of reliability in spatial data has been the subject of considerable recent research activity. Animation has been suggested as one method to achieve this, and its application to various measures associated with class-area maps (classified satellite images and soil maps) has been discussed elsewhere. Animation is achieved by randomly selecting a location and then assigning it to a different map unit (cover or soil type) according to the information on the reliability associated with the original map or map units. In this article the same basic method is extended to mapping locational reliability in dot maps and surface error in a digital elevation model (DEM). In the former case, the dots, which are randomly located in the first place, are randomly relocated so that any meaningless positional information implicit in the location of the dots is lost while the meaningful information (the number of dots within a region) remains constant. In the DEM, animation uses a random field as an error surface, based upon the root mean squared error (RMSE). The amount of error at a location is constantly changed, giving no impression that the elevation is precisely known. The ability to vary the spatial autocorrelation within the error field provides a graphic illustration that the usual RMSE is not a sufficient method for the reporting of error in spatial databases. In both examples animation of reliability is believed to make a novel, but appropriate, use of the computer in cartography. 相似文献
7.
M. Saandar 《国际地球制图》2013,28(3):69-71
Abstract A GIS based approach is proposed for the integration of three thematic maps viz. geomorphology, drainage density and slope using fuzzy logic for the assessment of ground water resource potential of a soft rock terrain of Midnapur District, West Bengal, India. The geomorphology and drainage density maps of the area are prepared from IRS‐1B LISS‐II data, and the slope map is obtained from the contours depicted on the topographic map of Survey of India. Each feature of all the thematic maps is assigned with individual fuzzy set values within a range between 0 to 1 according to their relative importance in the prediction of ground water occurrence. The maps are then integrated through fuzzy operation to model the ground water potential zone of the study area. The evolved model while verified with surface geophysical results is found to be in good agreement. 相似文献
8.
通过对当前大比例尺地形图更新存在问题的分析,对测绘大数据时代的大比例尺地形图在数据采集手段、加强历史数据的挖掘和利用、建立地图综合缩编系统、开展城市地下空间测绘等4个方面进行了探讨,总结了测绘大数据时代的大比例尺地形图更新机制和技术方法。 相似文献
9.
ABSTRACTSocial, economic, and environmental statistical data associated with geographic points are currently globally available in large amounts. When conventional thematic maps, such as proportional symbol maps or point diagram maps, are used to represent these data, the maps appear cluttered if the point data volumes are relatively large or cover a relatively dense region. To overcome these limitations, we propose a new type of thematic map for statistical data associated with geographic points: the point grid map. In a point grid map, an input point data set is transformed into a grid in which each point is represented by a square grid cell of equal size while preserving the relative position of each point, which leads to a clear and uncluttered appearance, and the grid cells can be shaded or patterned with symbols or diagrams according to the attributes of the points. We present an algorithm to construct a point grid map and test it with several simulated and real data sets. Furthermore, we present some variants of the point grid map. 相似文献
10.
J. Lin 《The Cartographic journal》2017,54(1):48-60
This study reunites areal interpolation with the isopleth mapping process to construct an inferred larger scale isopleth map. Intelligent areal interpolation is used to construct two types of population density surfaces that are used as inputs for pycnophylactic interpolation of an isopleth surface. One is a target zone population density surface (TZPDS) and the other is a control zone population density surface (CZPDS). Results suggest that an inferred isopleth map with remote sensing control data is a better surface depiction than an isopleth map without any control data, and the quality of such an isopleth map is further improved by enhancing the remote sensing data with residential parcel information. A CZPDS-derived intelligent isopleth map also has more peaks and variations in population distribution patterns than does a TZPDS-derived one due to the larger scale of the control data. 相似文献
11.
Field surveys are often a primary source of aboveground biomass (AGB) data, but plot-based estimates of parameters related to AGB are often not sufficiently precise, particularly not in tropical countries. Remotely sensed data may complement field data and thus help to increase the precision of estimates and circumvent some of the problems with missing sample observations in inaccessible areas. Here, we report the results of a study conducted in a 15,867 km² area in the dry miombo woodlands of Tanzania, to quantify the contribution of existing canopy height and biomass maps to improving the precision of canopy height and AGB estimates locally. A local and a global height map and three global biomass maps, and a probability sample of 513 inventory plots were subject to analysis. Model-assisted sampling estimators were used to estimate mean height and AGB across the study area using the original maps and then with the maps calibrated with local inventory plots. Large systematic map errors – positive or negative – were found for all the maps, with systematic errors as great as 60–70 %. After being calibrated locally, the maps contributed substantially to increasing the precision of both mean height and mean AGB estimates, with relative efficiencies (variance of the field-based estimates relative to the variance of the map-assisted estimates) of 1.3–2.7 for the overall estimates. The study, although focused on a relatively small area of dry tropical forests, illustrates the potential strengths and weaknesses of existing global forest height and biomass maps based on remotely sensed data and universal prediction models. Our results suggest that the use of regional or local inventory data for calibration can substantially increase the precision of map-based estimates and their applications in assessing forest carbon stocks for emission reduction programs and policy and financial decisions. 相似文献
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13.
We present a study on human perception of map complexity, with the objective of better understanding design decisions that may lead to undesirable levels of complexity in web maps. We compare three complexity metrics to human ratings of complexity obtained through a user survey. Specifically, we use two algorithmic approaches published by others, which measure feature congestion (FC) and subband entropy (SE), as well as our own approach of counting object types rather than individual objects. We compare these metrics with each other as well as with human complexity ratings for three maps of the same area from map providers Google Maps, Bing Maps, and OpenStreetMap. Each map design is assessed at three different scales (levels of detail). We find that (1) the FC and SE metrics appear to be adequate predictors of what humans consider complex; (2) object-type counts are slightly less successful at predicting human-rated complexity, implying that clutter is more important in perceived complexity than diversity of symbology; and (3) generalization choices do impact human complexity ratings. These findings contribute to our understanding of what makes a map complex, with implications for designing maps that are easy to use. 相似文献
14.
Field surveys are often a primary source of aboveground biomass (AGB) data, but plot-based estimates of parameters related to AGB are often not sufficiently precise, particularly not in tropical countries. Remotely sensed data may complement field data and thus help to increase the precision of estimates and circumvent some of the problems with missing sample observations in inaccessible areas. Here, we report the results of a study conducted in a 15,867 km² area in the dry miombo woodlands of Tanzania, to quantify the contribution of existing canopy height and biomass maps to improving the precision of canopy height and AGB estimates locally. A local and a global height map and three global biomass maps, and a probability sample of 513 inventory plots were subject to analysis. Model-assisted sampling estimators were used to estimate mean height and AGB across the study area using the original maps and then with the maps calibrated with local inventory plots. Large systematic map errors – positive or negative – were found for all the maps, with systematic errors as great as 60–70 %. The maps contributed nothing or even negatively to the precision of mean height and mean AGB estimates. However, after being calibrated locally, the maps contributed substantially to increasing the precision of both mean height and mean AGB estimates, with relative efficiencies (variance of the field-based estimates relative to the variance of the map-assisted estimates) of 1.3–2.7 for the overall estimates. The study, although focused on a relatively small area of dry tropical forests, illustrates the potential strengths and weaknesses of existing global forest height and biomass maps based on remotely sensed data and universal prediction models. Our results suggest that the use of regional or local inventory data for calibration can substantially increase the precision of map-based estimates and their applications in assessing forest carbon stocks for emission reduction programs and policy and financial decisions. 相似文献
15.
简述湖北旅游地图现状、品种、编制特点。分析目前湖北旅游地图存在的问题。提出改进和发展湖北旅游地图的对策:地图编制单位与旅游部门要加强沟通联系,测绘主管部门要加大对地图市场的监管力度,科学地运用当今先进测绘技术编制旅游地图,提高地图编印质量,丰富旅游地图品种。 相似文献
16.
《The Cartographic journal》2013,50(4):292-303
AbstractThe presentation of graphics and maps on the Internet has led to the development of several new techniques. The use of dynamics and animations in maps has increased, and new types of applications are emerging frequently. Recently, several map providers on the web have introduced zooming in maps as an animated operation. In this paper, we look closer into how the animated zoom is perceived by participants in an experiment, and compare these observations with a corresponding test where the map scale is changed in more abrupt steps. The results indicate significant preference for the animated zoom. The experiment itself is carried out through the World Wide Web and all the participants made their contribution from their own computers. 相似文献
17.
《The Cartographic journal》2013,50(2):208-212
AbstractTerrain data obtained from satellite imagery or by scanning existing contour maps is in raster mode. Such data may be compressed by detecting and storing the critical points of contour lines. When hand digitising a contour map, a trained digitiser operator would usually select points which visually appear to be critical points. Existing interpolation techniques often fail to restore the critical points, including turning points, to their original positions. This article illustrates the use of splines composed of quadratic Bézier curves with monotone curvature for rendering contour lines which are represented only by their turning and end points, such that the positions of the turning points are preserved. 相似文献
18.
Berny Sèbe 《The Cartographic journal》2013,50(1):91-92
AbstractSince the publication of the first waterway map in 1990, the Inland Waterways of Britain series has expanded to a total of twenty three individual maps, a national route planning map, the first ring atlas and a directory of the inland waterways which explores aspects of preservation, restoration and heritage. Many of the titles have featured in walking guides, directories, promotional literature and web sites. This paper outlines the development of the series from the first map, describing the maps themselves, tracking the evolution of production methodologies, defining marketing and sales strategies and discussing the decision-making processes behind the publication and introduction of new titles. 相似文献
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20.
简要讨论了MapGIS的主要功能,阐述了利用MapGIS软件制作地质图设计与制作成图的过程,以及不同专题图专题内容的表示方法。 MapGIS制图技术简化了纷繁复杂的传统地质制图过程,而且美观精确;空间分析技术可以将矢量数据和栅格数据综合制作出各种图形和图像文件,方便分析。介绍了地质图制作的工作流程、图像处理方法,以及图像生成之后地质图的校正美化。 相似文献