城市排水管网地理信息系统Mapinfo与ArcGIS之间的数据转换

建立城市排水管网地理信息系统是现代城市发展的需求,国外软件以Mapinfo和ArcGIS这两个GIS软件应用最为广泛.Mapinfo简单易学但不能提供高级的GIS分析功能,而ArcGIS数据管理功能强大,其Coverage数据格式存储了矢量数据间的拓扑关系,可以对数据进行各种空间分析,在高性能GIS应用系统开发方面,有着明显的优势等特点.介绍了将Mapinfo的Tab数据转换成ArcGIS的Coverage数据格式的方法,扩大了地理信息系统在给排水工程中应用的可行性.     

基于ArcGIS Engine 的全国水环境管理信息系统设计与实现

基于嵌入式GIS组件系统ArcGIS Engine 9.0,研究开发了全国重点水质测站水环境管理信息系统,实现对全国160多个重点水质测站长时间序列数据的整理入库、查询、统计分析以及成果输出可视化等功能,系统同时集成了水环境专业模型,实现了对水质测站数据水质评价、水质趋势分析以及水环境模型预测等功能,从而更具专业性和实用性。该系统的构建和运行,提高了水利部水环境监测评价研究中心为国家决策部门和公众服务的质量和效率,有利于促进我国水环境管理方式的变革、实现水利科技的信息化。     

ESRI产品在水利行业的应用

随着GIS技术的不断发展,GIS在水利行业的应用也越来越深入、越来越广泛.目前,ArcGIS在我国水利行业的应用已经颇具规模,在水资源管理、防汛抗旱、水土保持监测、水环境监测评估、水文地质、农田灌溉、水利工程规划等应用领域中得到了广泛的应用.     

黄河河道内建设项目信息系统开发与应用研究

基于ArcGIS平台,结合J2EE编程技术,设计和开发了黄河河道内建设项目信息系统,其关键技术是采用分布式数据交换中间件.该系统具有建设项目类型、项目建设状态、建设单位等的统计分析功能,以及建设项目属性数据和基于GIS的图形查询等功能.通过系统权限管理,可实现对各管理单位项目数据的实时录入与管理.     

CAD到ArcGIS的数据转换方法探讨

ArcGIS作为一款对地理数据进行创建、管理、整合与分析的综合系统软件,目前已在我国水利行业得到广泛应用,在水资源管理、防汛抗旱、水文地质、农田灌溉、水环境监测等项目中发挥了具大作用并产生很大影响。但该系统分析所依据的地图数据多来源于测绘部门,而传统测绘行业多使用CAD类辅助软件,因此如何更好的将CAD数据格式转换成GIS数据格式成为越来越被关注的问题。     

黄河口三维GIS设计与实现

利用ArcScene和ArcGlobe来组织三维场景数据,把ArcGIS Engine作为二次开发平台,在VS.NET 2005集成环境下,采用C#语言进行黄河口三维GIS的设计与开发.黄河口三维GIS具有场景配置、图层管理、三维查询、动态模拟、飞行漫游、书签管理等六大功能,实现了三维地形场景的组织和对黄河三角洲的三维浏览与信息查询,可对海岸线、等深线、断面等多年历史数据进行管理,能完成对海岸线变迁和冲淤演变的动态模拟与演示等.     

太湖流域典型区域水生态环境系统模拟平台研究

针对流域水环境管理数字化和业务化的需求,基于地理信息系统、数字可视化和计算机仿真技术,在.Net框架下采用C#语言,开发出太湖流域典型区域数字水环境系统平台.该平台以水生态环境模拟模型为核心,面向数据和用户、界面友好、方便操作,解决了模型输人复杂易错、数据管理困难、模拟结果可视性低的问题,将水生态环境模型和GIS功能无缝连接.实现了对流域环境过程的长期连续模拟预测和仿真演示.可为流域水环境管理和水污染防治提供技术支撑.     

基于GIS的三峡水库水环境管理系统

三峡水库蓄水以后,水体自净能力下降,水环境质量有下降趋势.建立基于GIS的水环境管理系统是对各污染源进行统一、实时管理,改变库区水体质量的有效措施之一.系统以数据库技术、GIS技术以及多媒体技术等诸多手段相结合,以水资源数据库为核心,通过简洁、友好的界面,实现了水质监测、水质评价、水环境预警和决策支持等功能,为决策者提供了实时生态环境信息与可靠的决策支持信息.     

基于ArcIMS的全国水环境WebGIS信息系统设计与实现

基于ArcIMS9.0系统,并结合ASP、JavaScript等编程技术,设计和开发了全国重点水质测站数据的WebGIS信息系统。该系统实现了全国160多个重点水质测站的水环境信息的WebGIS网络发布,并具有水质指标的最大值、最小值、平均值、超标物、超标倍数等方面的统计分析功能,具备评价时段水质指标的二维、三维图表分析功能,以及水环境信息属性数据查询和全国水质站点GIS图形查询功能。同时,通过该系统的权限管理功能,实现各级流域及各地水环境监测中心的水环境监测数据的网络上报与在线管理,以及水质评价数据的实时入库。     

基于Web GIS的移民信息管理系统设计

基于在线地图服务,ArcGIS js for API提供的接口,以征地移民信息数据为基础,开发了基于Web GIS的移民信息管理系统.系统基于B/S架构,提供全面的地图操作、数据录入、红线内查询检索、汇总统计、综合分析等功能,实现移民实物指标调查数据的集中存储,确保数据处理的准确性,满足征地移民智能化管理的需要.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。