基于ArcGIS模型构建器处理1∶5000专题地理信息数据的方法

在基于ArcGIS模型处理1∶5000专题地理信息数据过程中,数据的批量面擦除、批量数据整合和裁切、数据属性一致性检查、数据格式转换到外业调绘平板是生产过程中遇到的主要问题,为了提高作业效率,利用ArcGIS模型构建器对专题地理数据处理程序进行了研究。本文详细介绍了主要程序的关键技术和在实际应用中取得的较好效果。     

城市专题地图指标内容的分析和处理

专题地图指标内容的选择是专题地图设计和制作的前提。本文从分析城市专题统计数据的内容、特点出发,综合考虑专题地图表达的可行性和多样性,形成了一套完整的城市专题地图指标内容分析和处理方法。提出并使用了＂指标——空间——时间＂模型来描述专题地图指标内容,该方法的确立是选定专题地图主题和确立专题内容结构的基础。     

上海市主体功能区划分与综合制图

以《上海市主体功能区划图集》的数据处理、内容结构设计、地图设计与制作工艺等不同阶段遇到的问题及解决方案为例,探讨了此类反映总体规划、区域划分类地图(集)的设计特点与关键技术。     

预应力混凝土渡槽抗震性能的试验研究

基于预应力混凝土渡槽的低周反复荷载试验,对其受力过程、破坏形态、滞回曲线、刚度退化、耗能能力等抗震性能进行了研究与分析。试验结果表明：预应力混凝土渡槽的破坏形态为弯剪破坏,滞回曲线在加载的初期阶段表现出一定的捏拢效应,滞回曲线总体呈明显的梭形,且较为丰满,耗能能力强,抗震性能优良;配筋合适的预应力混凝土渡槽在加载初期对裂缝控制具有良好的表现,渡槽整体具有良好的延性;在整个加载过程中,渡槽试件的刚度退化明显,刚度退化主要集中在开裂后至屈服这一阶段。     

Attributes and uncertainty of dissolved zinc data from a mined catchment

This study evaluated the attributes and uncertainty of non‐point source pollution data derived from synoptic surveys in a catchment affected by inactive metal mines in order to help to identify and select appropriate methods for data analysis/reporting and information use. Dissolved zinc data from the Upper Animas River Basin, Colorado, USA, were the focus of the study. Zinc was evaluated because concentrations were highest relative to national water quality criteria for brown trout, and zinc had the greatest frequency of criteria exceedances compared with other metals. Data attributes evaluated included measurement and model error, sample size, non‐normality, seasonality and uncertainty. The average measurement errors for discharges, concentrations and loadings were 0·15, 0·1 and 0·18, respectively. The 90 and 95% coefficients of confidence intervals for mean concentrations based on a sample size of four were 0·48 and 0·65, respectively, and ranged between 0·15 and 0·23 for sample sizes greater than 40. Aggregation of data from multiple stations decreased the confidence intervals significantly, but additional aggregation of all data increased them as a result of increasing spatial variability. Unit area loading data were approximately log‐normal. Concentration data were right‐skewed but not log‐normal. Differences in median concentrations were appreciable between snowmelt and both storm flow and baseflow, but not between storm flow and baseflow. Differences in unit area loadings between all flow events were large. It was determined that the average concentration and unit area loading values should be estimated for each flow event because of significant seasonality. Time weighted values generally should be computed if annual information is required. The confidence in average concentrations and unit area loadings is dependent on the computation method used. Both concentrations and loadings can be significantly underestimated on an annual basis when using data from synoptic surveys if the first flush of contaminants during the initial snowmelt runoff period is not sampled. The ambient standard for dissolved zinc for all events was estimated as 1600 μg l⁻¹ using the 85th percentile of observed concentration data, with a 90% confidence interval width of 200 μg l⁻¹. Copyright © 1999 John Wiley & Sons, Ltd.     

青藏铁路格拉段典型沙害路段风沙地貌专题图编制

随着青藏铁路全线开通,风沙危害已成为影响铁路安全运营的主要环境问题之一。铁路沿线风沙危害路段主要集中在措那湖、沱沱河、北麓河等地。基于高分辨率卫星遥感影像QuickBird数据,通过野外实地勘察,同时参考Google Earth影像和DEM数据,绘制了3个典型沙害路段的风沙地貌专题图,地貌图比例尺为1:50000,采用二级分类系统,一级类为6个,共包含18个二级类。由于青藏铁路地处西风带中部急流区,风力强劲;铁路沿线生态环境脆弱、地表类型复杂,冻融和风蚀时空交错,地表沙物质丰富,风沙活动强烈而频繁,铁路沙害正呈现出迅速增长的态势。鉴于此,很有必要绘制青藏铁路沿线风沙灾害现状及防治措施布局的专题地图,为科学合理地制定青藏铁路沿线风沙危害综合防护体系提供依据。     

基于模板技术的专题海图快速成图方法研究

首先分析了当前专题海图的生产现状,在此基础上,探讨了模板技术对专题海图快速成图的意义,介绍了基于模板技术的专题海图快速成图技术,并对专题海图制图模板结构进行了总体设计;最后从成图模式、工具平台和应用系统三个方面对基于模板的专题海图快速成图进行了方法上的实现。     

Pile driving formulas based on pile wave equation analyses

Pile driving formulas, which directly relate the pile set resulting from a hammer blow to the static load capacity of the pile, are often used to decide whether a pile will have the required design capacity. However, existing formulas do not consider soil or pile type, and do not, in general, reliably predict pile capacity. In this paper, an advanced model for dynamic pile driving analysis was used to develop accurate pile driving formulas. The proposed driving formulas are validated through well-documented case histories. Comparisons of predictions from the proposed formulas with results from static and dynamic load tests show that they produce reasonably accurate predictions of pile capacity based on pile set observations.     

在线地图集发布与服务系统的设计与实现

地图集作为反映一个地区或一种领域研究成果的地图集合,是测绘行业的一个重要组成部分,传统地图集编制与发布的成果多为纸质版,制作与发布周期比较长,更新速度慢。该系统对在线地图集发布与服务系统进行开发,有效地缩短了地图集编制时间,提高了地图集编制与发布的效率。在对整个系统进行了完整的设计后,对相关关键技术进行了研究,最后实现了整个系统的开发,并对系统主要功能做出展示。     

面向大区域遥感专题制图的自动化策略

如何消除相邻影像间的信息冗余是实现大区域遥感自动化制图的关键。本文提出了一种基于约束接缝线的区域分块自动化制图方法,首先采用全球通用墨卡托投影-UTM投影的网格带将研究区分为若干小区域;然后,针对每个UTM投影带内的遥感影像,采用影像镶嵌的原理和湖泊边界约束条件计算其接缝线网络,以确定每景遥感数据制图范围;最后,根据其制图范围生成对应的无冗余专题信息,减少计算量和相邻影像重复信息的编辑时间。本文以亚洲中部干旱区为例开展湖泊制图试验,结果证明该方法能够生成顾及湖泊的有效制图范围,提高了遥感大区域制图的效率。