关于中小城市“三图并出”的探讨

本文从我国城市测绘的现状出发,分析城市测绘工作中存在的问题,并就具体问题探求解决的办法,提出了新形势下解决城市测绘问题的途径——三图并出     

Multipurpose geochemical maps produced by integration of geochemical exploration data sets in The Paraná Shield, Brazil

Old geochemical datasets from the Paraná Shield of southern Brazil have been integrated into a new geochemical database and the results are presented as a series of multipurpose geochemical maps. Although the 24 datasets retrieved were analysed by three different laboratories, the maps produced correlate surprisingly well with bedrock geological features.The retrieval of old geochemical exploration data sets for the purpose of generating maps showing element depletions and enrichments is a powerful tool with a wide range of applications: trace elements such as Zn, Cu and Mo can significantly affect crop productivity; areas with high abundances of harmful elements such as As and F can be delineated in order to identify public health hazards; heavy metals such as Cd, Pb and Hg can be measured in order to better constrain knowledge of chemical background levels for environmental monitoring. The integration and manipulation of different data sets can however be complicated by the heterogeneity in sampling and analytical procedures.     

东南极拉斯曼丘陵区大比例尺地貌图编制的理论与实践

分析制图说和综合制图说是目前国内外占主导地位的两种地貌制图体系。本文阐述了这两种体系的优劣。并设计出适合拉斯曼丘陵区的地貌制图系统，分步骤对地貌形态的五大要素进行分析取舍。并辅以营力分区图、古剥蚀面图等图件，使综合地貌图信息更丰富，同时清晰度和直观性亦得到保证。     

九寨沟自然保护区系列图研究

九寨沟是国家级自然保护区和重点风景名胜区。并载入联合国的《世界自然造产名录》．该沟生态环境十分脆弱，科学研究程度还相当低．两个国家自然科学基金课题对基生态环境进行了综台系统的研究，在此基础上编制而成的专题系列图填补了该区没有一套较完整图件的空白．文章介绍了系列图的编制背景、意义、选题、方法及特点等内容．     

利用DOM更新1：10000地形图平面精度的探讨

针对基础地理信息数据更新的现状,综合分析了利用数字正射影像图进行矢量化数据采集以更新DLG的误差源、未变要素在DLG与DOM中的偏差,并进行了更新成果精度分析,实例表明,分析结果合理、可行。     

Modeling the Pre-Euroamerican Landscape with Government Land Office Surveys and Geostatistics

Forested areas in the United States have been altered since the time of European settlement. There is increasing interest in comparing present day vegetation with that of the Pre-Euroamerican era to understand what changes have occurred in some of our more outstanding natural areas. Studies have been conducted using Government Land Office (GLO) notes to understand historic vegetation surveys, but past studies focused on species present/absent lists. The GLO surveys included information about tree species, tree diameter and other physical features. This study used indicator kriging to interpolate the probability of tree species on the landscape using the GLO data from 62 townships. Once continuous probability models were developed, vegetation spatial patterns were analyzed throughout the sub-basin. This technique provided insight into what the vegetation pattern (spatially) was like prior to Euroamerican settlement within the Buffalo River sub-basin. It provided the base information necessary to quantify vegetation change and the spatial extent of that change. Based on this research it appears that post-Euroamerican fire suppression and agricultural practices with other human activities have been major contributors to change. Eastern Redcedar ( Juniperious virginiana ) and hickory ( Carya sp .) have increased, while oak species ( Quercus sp .) have decreased. Additionally 19% of the sub-basin has changed to non-forest.     

Horizontal and vertical variability of soil properties in a trace element contaminated area

The spatial distribution of some soil chemical properties and trace element contents of a plot affected by the Aznalcóllar mine spill were investigated using statistical and geostatistical methods to assess the extent of soil contamination. Total and EDTA-extractable soil trace element concentrations and total S content showed great variability and high coefficients of variation in the three examined depths. Soil in the plot was found to be significantly contaminated by As, Cd, Cu, Pb and Zn within a wide range of pH. Total trace element concentrations at all depths (0–60 cm) were much higher than background values of non-affected soil, indicating that despite the clean-up operations, the concentration of trace elements in the experimental plot was still high. The spatial distribution of the different variables was estimated by kriging to design contour maps. These maps allowed the identification of specific zones with high metal concentrations and low pH values corresponding to spots of residual sludge. Moreover, kriged maps showed distinct spatial distribution and hence different behaviour for the elements considered. This information may be applied to optimise remediation strategies in highly and moderately contaminated areas.     

Interactive Videos Enhance Learning about Socio-Ecological Systems

Two forms of interactive video were assessed in an online course focused on conservation. The hypothesis was that interactive video enhances student perceptions about learning and improves mental models of social-ecological systems. Results showed that students reported greater learning and attitudes toward the subject following interactive video. Moreover, metrics of network complexity applied to students' concept maps of socio-ecological systems increased longitudinally through the course highlighting greater awareness of socio-ecological linkages. We conclude that interactive video can increase awareness of interdisciplinary connections in socio-ecological systems and should be more widely employed in general education geography courses.     

Online Survey of Heterogeneous Users and Their Usage of the Interactive Mapping Platform WorldMap

This article reports on the results of an online survey with 290 heterogeneous users of the interactive mapping platform WorldMap and provides insights into problems faced by such users. Heterogeneous users are users with a variety of GIS skills, educational background, gender, and age categories. We investigate how they interact with online maps and analyse their experience. WorldMap represents as a case study of an online mapping platform which aims to serve researchers and users across disciplines in viewing and creating online interactive maps. We concentrate on operations that are perceived as difficult and very difficult by the majority of users as well as operations that are rarely used. Our aim is to contribute to the discussions on how to improve the design of online GIS-based mapping platforms. We conclude the paper with reflections on the results of our study and ideas for further research.     

Exploiting Illusory Grid Lines for Object-Location Memory Performance in Urban Topographic Maps

In order to be successful in spatial orientation tasks, people need to recall locations and configurations of spatial objects from their memory. This understanding of geographic space often arises from experience with cartographic media representing topographic and topological information by graphic symbols. Learning spatial information from graphic media is influenced by different perception-based grouping effects distorting the accuracy of spatial object-positions and their relations. Such geometric inaccuracies can be softened by adding a grid layer, which regionalizes the map and can be used as an additional orientation pattern. This grid layer usually consists of solid lines and overlays semantic information. The present paper reports the results of two empirical studies on object-location memory (OLM) performance. In these studies, the amount of visual detail of the grid layer was reduced. By positioning the grid layer below specific urban topographic objects (study 1), the grid pattern was graphically interrupted. These interrupted grid lines were completed by cognitive completion mechanisms (illusory grid lines) described in the Gestalt principles of closure and continuation. The second experiment examined the maximum grid line gap that is closed by cognitive line completion and keeps an advantage for OLM (study 2).