MAPS AND METAPHORS

It has been argued that the confusion surrounding the term map in the expression, mental map, renders the expression meaningless. The confusion can be removed if we consider two sources of misunderstanding. First, there is a failure to appreciate the complex, double role that the map plays in our analogical thinking, and second, there is a failure to distinguish between the map as metaphor and the map as analogy.     

MAPS,METAPHORS AND MUDDLES

The idea of a cognitive or mental map has been a source of confusion in the geographical literature for some time. Downs suggests that the confusion can be removed if we give consideration to the role of maps in metaphors and analogies. This raises important questions, but treating the map as a double metaphor does nothing to clarify these issues. Cartographic skills are not the result of introspection and hypothesizing such maps-in-the-head can only impede our understanding of spatial behavior.     

A double continuous approach to visualization and analysis of categorical maps

A method to visualize multiple membership maps, called ‘Colour mixture’ (CM) is described and compared with alternative techniques: defuzzification and Pixel mixture. Six landform parameters were used to derive the landform classes using supervised fuzzy k-means classification. The continuous categorical map is derived by GIS calculations with colours, where colour values are considered to represent the taxonomic space spanned by the attribute variables. Coordinates of the nine class centres (landform facets) were first transformed from multivariate to two-dimensional attribute space using factor analysis, and then projected on the Hue Saturation Intensity (HSI) colourwheel. The taxonomic value was coded with the Hue and confusion with Saturation. To improve visual impression, saturation was replaced with whiteness. Classes that were closer in attribute space were merged into similar generic colours. The CM technique limits the derived mixed-colour map to seven generic hues independently of the total number of classes, which provides a basis for automated generalization. The confusion index derived from the mixed-colour map was used to derive primary boundaries and to locate areas of higher taxonomic confusion.     

How Textbooks Influence the Curriculum in Geography

Abstract

In this study, pairs of students in fifth and seventh grade generated and answered questions based on maps. More than 90 percent of the questions they generated made sense with reference to the map on which they were based. Each of these questions was coded in terms of both its informational content (symbols, latitude and longitude, and scale) and the process by which a map user obtains the information from the map (map reading, map interpreting, map inferring). Results indicated that students most often generated three types of questions, which together accounted for more than 80 percent of all the questions: 1) read symbol, 2) infer latitude and longitude, and 3) interpret scale. Qualitatively, the questions were analyzed for what they revealed about student confusion about map content. Problems with all three aspects of map content were common among both fifth- and seventh-grade students. The problem-posing technique proved useful for evaluating student's knowledge.     

基于纹理特征与数学形态学的高分辨率影像城市道路提取

从遥感影像上提取道路面临如下问题:根据光谱特征分类的图像存在建筑物与道路混淆,受交通工具、行道树等影响易产生道路中的孔洞与道路边缘的毛刺等。该文利用南京市IKONOS高分辨率影像丰富的空间纹理信息,将纹理信息加入原始波段参与分类,可以解决建筑物与道路的混淆问题。另外,道路具有丰富的形态特征,应用数学形态学的相关算法和形状指数,可以很好地去除道路提取过程中产生的各种噪声。     

Comparison of flood hazard assessments on desert piedmonts and playas: A case study in Ivanpah Valley, Nevada

Accurate and realistic characterizations of flood hazards on desert piedmonts and playas are increasingly important given the rapid urbanization of arid regions. Flood behavior in arid fluvial systems differs greatly from that of the perennial rivers upon which most conventional flood hazard assessment methods are based. Additionally, hazard assessments may vary widely between studies or even contradict other maps. This study's chief objective was to compare and evaluate landscape interpretation and hazard assessment between types of maps depicting assessments of flood risk in Ivanpah Valley, NV, as a case study. As a secondary goal, we explain likely causes of discrepancy between data sets to ameliorate confusion for map users. Four maps, including three different flood hazard assessments of Ivanpah Valley, NV, were compared: (i) a regulatory map prepared by FEMA, (ii) a soil survey map prepared by NRCS, (iii) a surficial geologic map, and (iv) a flood hazard map derived from the surficial geologic map, both of which were prepared by NBMG. GIS comparisons revealed that only 3.4% (33.9 km²) of Ivanpah Valley was found to lie within a FEMA floodplain, while the geologic flood hazard map indicated that ~ 44% of Ivanpah Valley runs some risk of flooding (Fig. 2D). Due to differences in mapping methodology and scale, NRCS data could not be quantitatively compared, and other comparisons were complicated by differences in flood hazard class criteria and terminology between maps. Owing to its scale and scope of attribute data, the surficial geologic map provides the most useful information on flood hazards for land-use planning. This research has implications for future soil geomorphic mapping and flood risk mitigation on desert piedmonts and playas. The Ivanpah Valley study area also includes the location of a planned new international airport, thus this study has immediate implications for urban development and land-use planning near Las Vegas, NV.     

Automatic mapping of lunar landforms using DEM-derived geomorphometric parameters

Developing approaches to automate the analysis of the massive amounts of data sent back from the Moon will generate significant benefits for the field of lunar geomorphology. In this paper, we outline an automated method for mapping lunar landforms that is based on digital terrain analysis. An iterative self-organizing (ISO) cluster unsupervised classification enables the automatic mapping of landforms via a series of input raster bands that utilize six geomorphometric parameters. These parameters divide landforms into a number of spatially extended, topographically homogeneous segments that exhibit similar terrain attributes and neighborhood properties. To illustrate the applicability of our approach, we apply it to three representative test sites on the Moon, automatically presenting our results as a thematic landform map. We also quantitatively evaluated this approach using a series of confusion matrices, achieving overall accuracies as high as 83.34% and Kappa coefficients (K) as high as 0.77. An immediate version of our algorithm can also be applied for automatically mapping large-scale lunar landforms and for the quantitative comparison of lunar surface morphologies.     

基于DEM和地貌计量的月球形貌类型自动制图（英文）

Developing approaches to automate the analysis of the massive amounts of data sent back from the Moon will generate significant benefits for the field of lunar geomorphology.In this paper,we outline an automated method for mapping lunar landforms that is based on digital terrain analysis.An iterative self-organizing(ISO)cluster unsupervised classification enables the automatic mapping of landforms via a series of input raster bands that utilize six geomorphometric parameters.These parameters divide landforms into a number of spatially extended,topographically homogeneous segments that exhibit similar terrain attributes and neighborhood properties.To illustrate the applicability of our approach,we apply it to three representative test sites on the Moon,automatically presenting our results as a thematic landform map.We also quantitatively evaluated this approach using a series of confusion matrices,achieving overall accuracies as high as 83.34% and Kappa coefficients(K)as high as 0.77.An immediate version of our algorithm can also be applied for automatically mapping large-scale lunar landforms and for the quantitative comparison of lunar surface morphologies.     

On the origin,meaning, and evaluation of urban governance

The article shows that although a large literature has been produced on the concept of urban governance, its meaning remains ambiguous. The aim of the article is not to ‘prove’ that there is confusion in the concept or to rectify that confusion, but rather to consolidate, categorise, and synthesise the many meanings of urban governance. The article argues that when the concept of ‘urban governance’ is regarded as a cluster of meanings, particularly as decentralisation, entrepreneurialism, and democratisation (DED) and repositioned in a broad political-economic and socio-cultural framework, its full tenor can be grasped for future research.     

Classification of Soil Groups Using Weights-of-Evidence-Method and RBFLN-Neural Nets

Weights-of-Evidence (WofE) and Radial Basis Function Link Net (RBFLN) were applied to soil group mapping in eastern Finland. The data consisted of low altitude airborne geophysical measurements, Landsat 5 TM-satellite image, and digital elevation model (DEM) and slope information derived from it. Probability maps were constructed for each soil group one by one and combined into a prediction map of soil groups using maximum posterior probability (WofE) or pattern membership (RBFLN). Self-Organizing Map (SOM) and Sammon’s Mapping were applied for selecting the data sets for modeling and visualizing the data. The soil types belonging to each soil group used in the Arc-SDM modeling were defined by clusters revealed by the SOM and Sammon’s Mapping algorithms. The soil types with similar characters were collected in the same cluster. Numerical evaluation of the models’ performance was performed using the confusion matrix. The Ratio of Correct Classifications (RCC) for the best WofE model was 0.64 in the training area and 0.61 in the testing area. The RCC for the best RBFLN model was 0.62. Modeling of soil groups using Arc-SDM is time consuming because models need to be constructed for each soil group before combining them into a final prediction map. In this study a simple method was tested for combining the maps. In the future, more attention should be paid to combining the posterior probability models and also to selecting data sets used for modeling.     

Volume 111 Index

Abstract

Concepts related to alternative map projections can be difficult to explain to students given the diversity and complexity of available projections. Students frequently have trouble understanding how distortions caused by the choice of a projection can affect map readability and comprehension. Programs available for personal computers now provide geography and cartography instructors with a method for interactively educating students concerning the distortions associated with alternative map projections. Such software can be incorporated into laboratory assignments in introductory geography courses or in more advanced courses that deal with map design or thematic cartography.     

基于决策树模型的海岸带分类方法研究

海岸带地物分布复杂,地物混淆常造成海岸带提取困难。该文以江苏省粉砂淤泥质海岸为研究对象,运用图像光谱特征、纹理特征并引入地学知识,构建研究区遥感图像分类决策树模型,并利用ETM 图像进行海岸地物分类研究。结果表明:采用的决策树模型可以较好地结合纹理信息和地学知识,解决遥感图像中复杂地物分类过程中的混淆现象,分类精度达89.26%,比最大似然法分类精度提高了15.19%。     

An OLS regression model for context-aware tile prefetching in a web map cache

The increasing popularity of web map services has motivated the development of more scalable services in the spatial data infrastructures. Tiled map services have emerged as a scalable alternative to traditional map services. Instead of rendering map images on the fly, a collection of pre-generated image tiles can be served very fast from a server-side cache. However, during the start-up of the service, the cache is initially empty and users experience a poor quality of service. Tile prefetching attempts to improve hit rates by proactively fetching map images without waiting for client requests.

While most popular prefetching policies in traditional web caching consider only the previous access history to make predictions, significant improvements could be achieved in web mapping by taking into account the background geographic information.

This work proposes a regressive model to predict which areas are likely to be requested in the future based on spatial cross-correlation between an unconstrained catalog of geographic features and a record of past cache requests. Tiles that are anticipated to be most frequently requested can be pre-generated and cached for faster retrieval. Trace-driven simulations with several million cache requests from two different nation-wide public web map services in Spain demonstrate that accurate predictions and performance gains can be obtained with the proposed model.     

Integration of multi-source remote sensing data for land cover change detection

The objective of this study is to develop a methodology to integrate multi-source remote sensing data into a homogeneous time series of land cover maps in order to carry out change detection. We developed a method to increase the comparability between land cover maps coming from panchromatic aerial photographs and SPOT XS (multi-spectral) data by equalizing their levels of thematic content and spatial details. The methodology was based on the hypotheses that: (1) map generalization can improve the integration of data for change detection purpose, and (2) the spatial structure of a land cover map, as measured by a set of landscape metrics, is an indicator of the level of generalization of that map. Firstly, the methodology for data integration was developed by using land cover maps generated from near-synchronous data. Results revealed that, by controlling successively the parameters that influence the level of map generalization, the percentage of agreement between the near-synchronous land cover maps can be increased from 42% to 93%. The computation of five landscape metrics for a set of generalized land cover maps and for the target map allowed us to optimize the level of generalization by measuring the similarity in landscape pattern of the maps. The optimum level of generalization of the land cover map obtained from the aerial photographs for comparison with a land cover map derived from SPOT XS data was found at a resolution of 41m for two generalization levels of the thematic content. The spatial structure of a land cover map, as measured by a set of landscape metrics, is thus a good indicator of the level of generalization of this map. Secondly, the method was applied by integrating a land cover map obtained from aerial photographs of 1954 with a land cover map obtained from a SPOT XS image of 1992.     

关于沙漠化地图编制的原则与方法

沙漠化是当前一个世界性的重要环境问题,其结果造成生物生产量的下降,土地生产潜力的衰退和可利用土地资源的丧失。它影响到全球陆地面积的1/3和占世界14%的人口,而且每年还以5-7万平方公里面积的速度在蔓延,因此沙漠化的防治便成为全球所关心的一个生态问题和环境保护问题。     

Computation and visualisation of the accuracy of old maps using differential distortion analysis

The accuracy of old maps can hold interesting historical information, and is therefore studied using distortion analysis methods. These methods start from a set of ground control points that are identified both on the old map and on a modern reference map or globe, and conclude with techniques that compute and visualise distortion. Such techniques have advanced over the years, but leave room for improvement, as the current ones result in approximate values and a coarse spatial resolution. We propose a more elegant and more accurate way to compute distortion of old maps by translating the technique of differential distortion analysis, used in map projection theory, to the setting where an old map and a reference map are directly compared. This enables the application of various useful distortion metrics to the study of old maps, such as the area scale factor, the maximum angular distortion and the Tissot indicatrices. As such a technique is always embedded in a full distortion analysis method we start by putting forward an optimal analysis method for a general-purpose study, which then serves as the foundation for the development of our technique. Thereto, we discuss the structure of distortion analysis methods and the various options available for every step of the process, including the different settings in which the old map can be compared to its modern counterpart, the techniques that can be used to interpolate between both, and the techniques available to compute and visualise the distortion. We conclude by applying our general-purpose method, including the differential distortion analysis technique, to an example map also used in other literature.     

人口密度空间化的一种方法

人口密度空间化是地理学中一个重要的研究课题,但是传统方法直接生成的人口密度分布图具有不同区域间突变的缺点。该文中基于面积权重内插法与邻域平均法原理,以MapInfo为软件平台,在缺乏地形图、RS图片等资料的情况下,提出人口密度空间化的一种方法——网格单元面积权重内插法,并以丰县为研究区域进行例证。结果表明：该方法有效缓和了传统方法直接生成的人口密度图中的突变线,制作的人口密度Grid专题地图能够很好地反映人口密度的平均性,生成的人口密度三维可视化地图符合人口密度的空间分布特点。     

空间认知对等导航电子地图的简化探讨

基于地图功能的改变和移动服务独特的用图环境,提出采用“空间认知对等地图”以满足导航用户的认知需求;介绍“空间认知对等地图”的概念和地图中应表现的认知信息、地图的简化过程和简化过程中的拓扑关系维护,给出地图的简化效果。这种地图不仅能满足空间认知需要,而且能缓解目前在LBS应用中存在的地图数据与屏幕大小的矛盾,适应移动环境下用户的多行为状态和终端硬件特点。     

A new pseudocylindrical equal-area projection for adaptive composite map projections

The recently introduced adaptive composite map projection technique changes the projection to the geographic area shown on a map. It is meant as a replacement for the commonly used web Mercator projection, which grossly distorts areas when representing the entire world. The original equal-area version of the adaptive composite map projection technique uses the Lambert azimuthal projection for regional maps and three alternative projections for world maps. Adaptive composite map projections can include a variety of other equal-area projections when the transformation between the Lambert azimuthal and the world projections uses Wagner’s method. To select the most suitable pseudocylindrical projection, the distortion characteristics of a pseudocylindrical projection family are analyzed, and a user study among experts in the area of map projections is carried out. Based on the results of the distortion analysis and the user study, a new pseudocylindrical projection is recommended for extending adaptive composite map projections. The new projection is equal-area throughout the transformation to the Lambert azimuthal projection and has better distortion characteristics then small-scale projections currently included in the adaptive composite map projection technique.