A computational procedure for joining separate map sheets

Map sheets have been often used as a basic spatial unit for managing spatial data produced from paper maps. This often results in incompatibility between adjacent map sheets, because spatial objects do not cross the boundaries smoothly and even the boundaries themselves do not match their neighbors exactly. To solve the problem this paper proposes a computational procedure for joining separate map sheets to obtain seamless spatial data. Line objects digitized separately in different map sheets are considered, which are frequently used to represent road networks, gas pipelines, and boundaries of polygon objects. The procedure consists of three steps: (1) extraction of end nodes, (2) detection of matching nodes, and (3) transformation of the map sheet. Each step goes interactively so that unexpected errors can be avoided by human observation. To test the validity of the procedure, map sheets are combined containing the road network data of Tokyo 23-ku area, Japan. This revised version was published online in July 2006 with corrections to the Cover Date.     

机载扫描激光地面测绘系统分析

本文根据机载扫描激光地面测绘系统的功能和要求，分析了它的工作原理，概括出该系统中扫描激光测距的特点，介绍了一种最新的机载扫描激光地面测绘系统，最后提出了几个需要继续研究的问题     

东昆仑造山带海西—印支期东昆南前陆盆地构造岩相古地理

地层相态的恢复对于研究非史密斯地层区沉积盆地的演化过程有着非常重要的意义。在1∶ 2 5万野外地质填图基础上作出了东昆仑造山带东段东昆南前陆盆地晚二叠世至中三叠世构造岩相古地理图 ,该系列图揭示了东昆南前陆盆地在 5个发展阶段中的岩相分布特征和空间上的古地理展布范围 ,即晚二叠世早期东昆南前陆盆地发育的初始阶段、晚二叠世晚期前陆盆地的扩展至短期萎缩阶段、早三叠世早期前陆盆地的再次扩展阶段、早三叠世晚期盆地发育的高峰阶段和中二叠世前陆盆地的萎缩至消亡阶段。东昆南前陆盆地的演化过程在一定程度上反映了构造对沉积的控制作用     

用低速带切除法提高构造图精度

塔里木盆地内地表面巨厚的沙层是油气勘探的主要障碍。本文在构造解释中用切除法把地表面低速的、不稳定的沙层切除,然后通过折射波反演方法,得其厚度,从而提高了构造图的精度。     

1∶5万区域地质调查数字地质图系统设计方案

根据地矿部“地矿工作信息化工程”总体部署,地调局设立了区调数字地质图系统的研究项目。其目的是通过试验研究解决１∶５万区调数字地质图的数据标准问题,制订统一的工作流程和技术要求,推广应用ＧＩＳ技术。重点论述了项目的目标、意义、研究内容、技术路线、图层划分、工作流程等方面的内容。     

鄂尔多斯早古生代古构造

用野外露头剖面、钻井剖面和地震剖面相结合的综合研究方法,首先用人工合成记录结合11口井的VSP资料,对鄂尔多斯下古生界进行层位标定。在此基础上,对鄂尔多斯全区下古生界371条共长15 683 km的地震剖面进行了重新处理和地层解释,这大大提高了解释精度。以此为基础,把鄂尔多斯下古生界划分为5个地层单位,即寒武系中下部、寒武系中上部及冶里组和亮甲山组、马家沟群下部、马家沟群上部、平凉组和背锅山组,并作出了它们的等厚图。从这些等厚图可以看出：前4个地质时期的古构造格局为“一隆三凹”,即西缘凹陷、南缘凹陷和东缘凹陷(或东部凹陷)呈“U”形从西南东三面包围着一个中部隆起。最后一个地质时期的古构造格局为“一隆二凹”,即西缘凹陷和南缘凹陷呈“L”形镶嵌在一个巨大的鄂尔多斯隆起的西缘和南缘。到奥陶纪末,鄂尔多斯全区以及整个华北地台均变为隆起区,从而结束了鄂尔多斯隆起和凹陷并存的历史。     

中国南方二叠纪层序岩相古地理特征及演化

在层序地层研究基础上,以沉积体系域和相关界面为编图单元,采用体系域压缩法和瞬时作图法,以油气勘探为目标,有针对性的编制了中国南方二叠纪11张层序岩相古地理图。在此基础上,全面系统地阐述了该区二叠纪层序岩相古地理特征及演化。结果表明,中国南方二叠纪层序古地理演化具有明显的继承性、不均一性、阶段性、方向性和同步性。与传统的岩相古地理图相比,层序岩相古地理图具有动态、精确、等时、成因连续和勘探实用等优点。     

第四纪地质图件和生态与环境图系的编制及展望

近２０年来,随着全球水资源,地质灾害,土壤利用及沙漠化等问题的日益严重,国内外不少部门和专家相应地编制了第四纪地质图件和生态瑟环境系列图件,提高一第四纪研究的水平,也为国土整治提供了科学依据。本篇主要通过这些图件来分析当前第四纪地质图和生态与环境系列图编制的动态和问题。     

GPS电子地图的设计与实现

随着计算机科学技术和地理信息系统以及全球卫星定位系统（ＧＰＳ）的发展,产生了一门新的应用领域———ＧＰＳ电子地图．根据电子地图的特点,介绍了自行开发设计的ＧＰＳ电子地图系统的结构、功能及实现方法．     

Flood hazard delineation combining geomorphological and hydrological methods: an example in the Northern Iberian Peninsula

Flood mapping requires the combination and integration of geomorphological and hydrological-hydraulic methods; however, despite this, there is very little scientific literature that compares and validates both methods. Two types of analysis are addressed in the present article. On the one hand, maps of flood plains have been elaborated using geomorphological evidence and historical flood data in the mountainous area of northwestern Spain, covering an area of more then 232 km² of floodplains. On the other hand, a hydrometeorological model has been developed (Clark semidistributed unit hydrograph) in the Sarria River basin (155 km², NW Spain). This basin is not gauged, hence the model was subjected to a goodness-of-fit test of its parameter (curve number) by means of Monte Carlo simulation. The peak flows obtained by means of the hydrological model were used for hydraulic modeling (one-phase, one-dimensional and steady flow) in a 4 km² urban stretch of the river bed. The delineation of surface areas affected by floods since 1918, as well as those analyzed subsequent to the geomorphological study, reveals a high degree of reliability in the delineation of the flooded areas with frequent recurrence intervals (<50 years). If we compare these flooded surface areas with the estimate obtained by the hydrological-hydraulic method we can see that the latter method overestimates the extent of the surface water by 144% for very frequent recurrence intervals (>10 years) and underestimates it as the recurrence interval increases, by up to 80% less floodplain for exceptional events (>500 years). Finally, a management map is put forth combining the most reliable results available by integrating both methods. Originally presented at the Sixth International Conference on Geomorphology.