构建基于AJAX和OGC标准的网络地图服务

随着Web2．0概念的兴起，Web应用更强调用户与页面的交互和Web应用程序之间的交互。而目前为满足这两点采用的主要方法是AJAX技术和信息交换标准。针对网络地图应用领域，对AJAX和OGC标准做了简要介绍，同时详细探讨了基于AJAX和OGC标准的网络地图服务的原理和架构。实例证明，采用AJAX和OGC标准可以创建界面友好，同时兼具标准性和开放性的网络地图服务。     

地图分析在城市规划布局中的应用

地图分析是地图高级应用的核心基础。应用连续化结构变换方法和点状地物表象空间分布特征分析方法，对长春市邮政机构分布图进行定性和定量分析。结果表明，长春市邮政机构分布比较合理。地图分析为城市规划布局提供科学依据，对其它行业布局也有一定的参考价值。     

地图诞生记

地图是我们生活中不可或缺的一种工具，当你初来乍到一个地方，免不了依靠地图来避免迷路；在工作中，地图往往也为我们提供一些必须的数据信息。人们离不了它，但是地图到底是如何制作、生产出来的，恐怕就没有几个人能说得清。本期“热点”为大家介绍“一幅地图的诞生记”。     

计算机图形软件编制地图的探讨

阐述了利用Coreldraw8．0图形软件来完成《连云港市市区图》的设计和具体编制的方法，利用Coreldraw8．0图形软件的特性来提高制图效率、成图质量。结合在地图编制工作中遇到的问题，对计算机制图和传统地图理论的结合、发展提出一些看法。     

应急地图如何“应急”

5月6日，湖南省地网院接到省委办的电话，要他们为5月18日开幕的“中博会”提供《湖南省地图》、《长株潭城市群地网》以及《长沙市城区地图》等应急地图，时间只有短短的3天。     

湖南互联网“问题地图”不再成“问题”

最近，一则“苹果须拿地图牌照”的新闻又将“互联网地图服务资质”这一今年3月起实行的互联网地图服务准入条件置于风口浪尖。其背景是谷歌在华申请地图牌照屡遭波折后，苹果能否顺利获得牌照增加了不确定因素。     

1：25万，湖南第一张自主编制的地形图

地图是人们的另一双眼。湖南省地图编制史可以追溯到2100多年前，长沙马王堆汉墓3号汉墓出土的3幅帛地图是公元前168年以前制作的，也是世界上发现的最早地图。     

基于Java Applet的Internet地图服务平台设计

论述了网络环境下建立地图服务平台的设计思路与结构设计,在此基础上对矢量地图数据基本流程做了详细的论述,其中主要包括数据获取、数据压缩、数据传输、数据表达与空间查询等.基于Java语言,从底层实现了基于Socket协议连接的服务器端与客户端地图数据的组织、传输与数据可视化表达,实现了网络地图发布平台.主要讨论了Java环境下具体地图服务平台设计.     

奥维互动地图在赫章高位隐蔽地质灾害排查中的应用

常规的"图纸+GPS"野外调查方法已无法满足现阶段地质灾害排查工作的需要,为寻求高效、精准、高质量的地质灾害数据采集技术,作者结合赫章县高位隐蔽性地质灾害隐患专业排查项目,以奥维互动地图的应用为研究对象,通过分析奥维互动地图的技术优势,并针对地质灾害排查工作中存在的导航找点难、信息采集过程繁琐、调查底图制作费时等系列问题,探索了奥维互动地图在赫章县高位隐蔽地质灾害排查中的应用,包括外部矢量数据源处理与导入、地质灾害解译、路线导航、点位查找、信息采集、位置共享以及内业成果处理等;提出了较为系统高效的地质灾害野外调查技术与方法。研究成果可为今后地质灾害野外调查环节提供技术参考。     

古今中外罕见的地图世家

在我国近代地图史上，可以称为地图世家的，大概只有湖南新化邹氏家族。从清朝乾隆末年起到20世纪70年代，邹氏家族七代相承，持续180余年，致力舆地学研究，著书近200种，印刷出版地图300余种，其传承时间之长，成就贡献之大，为古今中外所罕见。     

贵州省1：50万地球化学图编图方法

本文是一份编图方法的总结。文中简要介绍了使用计算机编图的方法和技术，它包括从数据入库、参数统计、数据系统偏倚的屏幕动态调整、色区值的选用、色块图的动态显示到图形的绘制等都使用计算机处理。此项技术投入资金少，但经济效益和成图质量好，故具有一定的实用价值。     

Computer-composite mapping for geologists

A computer program for overlaying maps has been tested and evaluated as a means for producing geologic derivative maps. Four maps of the Sugar House Quadrangle, Utah, were combined, using the Multi-Scale Data Analysis and Mapping Program, in a single composite map that shows the relative stability of the land surface during earthquakes. Computer-composite mapping can provide geologists with a powerful analytical tool and a flexible graphic display technique. Digitized map units can be shown singly, grouped with different units from the same map, or combined with units from other source maps to produce composite maps. The mapping program permits the user to assign various values to the map units and to specify symbology for the final map. Because of its flexible storage, easy manipulation, and capabilities of graphic output, the composite-mapping technique can readily be applied to mapping projects in sedimentary and crystalline terranes, as well as to maps showing mineral resource potential.     

Use of fuzzy relations to produce landslide susceptibility map of a landslide prone area (West Black Sea Region, Turkey)

Preparation of landslide susceptibility maps is important for engineering geologists and geomorphologists. However, due to complex nature of landslides, producing a reliable susceptibility map is not easy. For this reason, many procedures have been used to produce such maps. In this study, a new attempt is tried to produce landslide susceptibility map of a part of West Black Sea Region of Turkey. To obtain the fuzzy relations for producing the susceptibility map, a landslide inventory database is compiled by both field surveys and airphoto studies. A total of 266 landslides are identified in the study area, and dominant mode of failure is rotational slide while the other mode of failures are soil flow and shallow translational slide. The landslide inventory and the parameter maps are analyzed together using a computer program (FULLSA) developed in this study. The computer program utilizes the fuzzy relations and produces the landslide susceptibility map automatically. According to this map, 9.6% of the study area is classified as very high susceptibility, 10.3% as high susceptibility, 8.9% as moderate susceptibility, 27.5% as low susceptibility and 43.8% as very low susceptibility or nonsusceptible areas. The prediction performance of the susceptibility map is checked by considering actual landslides in the study area. For this purpose, strength of the relation (r_ij) and the root mean square error (RMSE) values are calculated as 0.867 and 0.284, respectively. These values show that the produced landslide susceptibility map in the present study has a sufficient reliability. It is believed that the approach employed in this study mainly prevents the subjectivity sourced from the parameter selection and provides a support to improve the landslide susceptibility mapping studies.     

Preliminary seismic hazard maps of Slovenia

The preparation of the preliminary seismic hazard maps of the territory of Slovenia has been based on an expansion of the basic approach laid out by Cornell in 1968. Three seismic source models were prepared. Two of them are based mainly on the earthquake catalogue using the Poissonian probability model. A map of seismic energy release and a map of earthquake epicenter density are used to delineate seismic sources in these models. The geometry of the third model which is based on a rough estimate of seismotectonic setting is taken from the probabilistic seismic hazard analysis of a nuclear power plant in Slovenia. Published ground motion attenuation models based on strong motion records of recent strong earthquakes in Italy are used. Test maps for variable and uniform b-values are presented. The computer program, Seisrisk III, developed by the U.S. Geological Survey is used.     

MAPGIS在水文地质制图中的应用

利用功能强大的ＭＡＰＧＩＳ系统,根据水文地质图的编制特点,笔者利用ＶｉｓｕａｌＦｏｘｐｒｏ开发了ＭＡＰＧＩＳ数据接口程序ＭＡＰＨＹＤＲＯ,成功地编制了矿井综合水文地质图,为机助编制各类水文地质图提供了一条可行的途径。     

由野外实测数据直接生成MAPGIS地质基础图件方法

传统纸介质手工制图存在信息实时再现滞后、共享交换不便等弊端,即便目前普遍使用计算机制图,也只是对纸介质底图进行二次描绘,不是真正意义上的计算机数字化制图和专业应用.因此,由野外实测数据直接进机处理生成地质基础图件,已成为专业人员在实际工作中急需解决的实际问题.笔者尝试以中国地质大学开发的MAPGIS6.6为主,辅以常用图表处理软件等,将原始数据转换成MAPGIS明码格式文件,导入成图系统,经系统处理直接成图,基本解决了野外实测数据直接进机处理生成地质基础图件的问题,其成图精度高,基本图形、数据共享,成果信息实时再现,能够进行基本的空间分析,可实现信息全息化,成图质量可通过源数据检查等.     

Empirical-based seismically induced slope displacements in a geographic information system environment: a case study

Landslides are one of the most damaging and threatening hazards associated with seismically induced slope movements. Estimations of support conditions for slope displacements are important for taking preventive measures to avoid landslide events in future. California's Division of Mines and Geology (DMG) procedure is utilised in the present paper for estimating the slope failure mechanism under seismic conditions. In this study, the DMG procedure has been explained and has also been incorporated in a Geographic Information System (GIS) using Arc-GIS software from Environmental Systems Research Institute. Further, it is utilised for establishing a seismically induced slope displacement map for the Skien municipality area of Telemark County in Norway. The motivation for selecting this site was the availability of geotechnical parameters for the site. Three different displacement maps have been produced for earthquake scenarios of magnitude 5, 6 and 7, respectively. The maximum displacement of 133 cm is estimated for earthquake scenario of magnitude 7. It is noticed that the sensitive areas for slope failure remain the same under different earthquake scenarios. A displacement tool based on the DMG procedure has been created in the Arc-tool box in Arc-GIS software. This tool minimises the efforts for inserting formulas for making raster displacement maps. By using the displacement tool one can generate final products like displacement maps automatically at high accuracy and in quick time. The prepared slope displacement maps of study area are used for landslide susceptibility zonation (LSZ) map preparation. The LSZ maps are useful for landslide hazard assessment and further can be utilised by planners, civil engineers and local administrators for town planning and policy-making.     

Application of vectors for suitability of landforms in siting surface water harvesting structures

The Survey of India toposheet number 64 G/12 was used as a source of information pertaining to contours, urban features, drainage and lakes and surface water harvesting structures. The commercially available software Surfer was used in this study. Contours were digitized, on screen, from the scanned base map. These data were then interpolated to obtain intermediate contour lines. Using the contour data, a wireframe map was generated to visualize the topography and ground slope variation in three-dimension. Vectors are emplaced over contour and wireframe maps to evaluate the gradient variation in topography. It is evident that the ground slope facilitates the movement of surface water runoff, and is directly proportional. The vector map helps in emphasizing the correlation of ground slope and surface water flow for the topographic analysis of landform for the siting of surface water harvesting structures. Vector maps can be guiding tool for the construction of surface water runoff structures/traps for augmentation of artificial recharge. This is a very fast and reliable method to evaluate the utility of the proposed structure to be used for surface water harvesting before actual construction, and it can be of help to evaluate the suitability of the structure for its maximum utilization.     

利用AUTOCAD软件求取图形面积

利用计算机辅助设计与绘图软件ＡＵＴＯＣＡＤ在计算机及其外设数字化仪上求取规则或不规则形状图形的面积和周长，在速度、精度、操作简单程度等许多方向，不但优于传统的各种求和只仪，也比一些专门为计算机及其外设数字化仪编制的求积软件优越，它既可专门求取某一图形的面积和周长，亦可以利用ＡＵＴＯＣＡＤ软件所绘图形文件中任一图形的面积和周长。如何充分得软件求取图形面积和周长的方法作了较全面的介绍。     

Landslide hazard mapping along national highway-154A in Himachal Pradesh,India using information value and frequency ratio

For the socio-economic development of a country, the highway network plays a pivotal role. It has therefore become an imperative to have landslide hazard assessment along these roads to provide safety. The current study presents landslide hazard zonation maps, based on the information value method and frequency ratio method using GIS on 1:50,000 scale by generating the information about the landslide influencing factors. The study was carried out in the year 2017 on a part of Ravi river catchment along one of the landslide-prone Chamba to Bharmour road corridor of NH-154A in Himachal Pradesh, India. A number of landslide triggering geo-environmental factors like “slope, aspect, relative relief, soil, curvature, Land Use and Land Cover (LULC), lithology, drainage density, and lineament density” were selected for landslide hazard mapping based on landslide inventory. The landslide inventory has been developed using satellite imagery, Google earth and by doing exhaustive field surveys. A digital elevation model was used to generate slope gradient, slope aspect, curvature, and relative relief map of the study area. The other information, i.e., soil maps, geological maps, and toposheets, have been collected from various departments. The landslide hazard zonation map was categorized namely “very high hazard, high hazard, medium hazard, low hazard, and very low hazard.” The results from these two methods have been validated using area under curve (AUC) method. It has been found that hazard zonation map prepared using frequency ratio model had a prediction rate of 75.37% while map prepared using information value method had prediction rate of 78.87%. Hence, on the basis of prediction rate, the landslide hazard zonation map, obtained using information value method, was experienced to be more suitable for the study area.