Generation of synthetic water demand time series at different temporal and spatial aggregation levels

This paper presents a procedure for the generation and spatial-temporal aggregation of synthetic water demand time series which reproduce the main statistics - mean, variance and (spatial and temporal) covariance - of the corresponding observed series. Starting from observed historical time series taken at low levels of temporal aggregation (e.g., one minute) and relating to individual users, the procedure enables a) the generation of synthetic water demand time series for every individual user with a time step of one minute, b) the temporal aggregation of these synthetic series in order to obtain synthetic water demand time series with a time step, for example, of one hour, and which are such as to reproduce the hourly mean, variance and temporal covariances of the corresponding temporally aggregated historical time series, and c) the spatial aggregation of the synthetic hourly water demand time series of every user in order to generate a synthetic water demand time series that is representative of the entire group of users considered, and is such as to reproduce the mean, variance and temporal covariance observed at that level of spatial aggregation; The entire procedure was parameterized and applied to a case study on the water demands of 21 users of the water distribution system of Milford (Ohio). The results obtained show that the temporal aggregation procedure is effective in generating hourly water demand time series that preserve the mean, variance and temporal correlation of the historical time series for every individual user, while the spatial aggregation method shows good level of effectiveness in preserving the statistics of the aggregated series. Overall, the proposed procedure is demonstrated to be a valid tool for the bottom-up generation of synthetic water demand time series at various levels of spatial-temporal aggregation which reproduce the mean, variance and covariance statistics of the historical time series.     

从需水量探索茂名市中水回用的必要性

通过茂名市城区生活及工业需水量预测分析,建议茂名市进行中水回用的技术研究,及早开辟第二水源,为建设节水型茂名提供参考,并进一步证明了茂名市市区生活污水回用于生活和工业用水的必要性。     

中水系统的发展及应用综述

介绍了中水系统的发展应用概况，结合目前的研究介绍了中水系统的水源选用、管路配置、处理工艺及系统设置等技术原则，并对其今后的发展方向做了展望。     

山西省城镇供水现状及用水需求发展趋势

针对山西省城镇供水现状进行了分析,分别阐述了全社会供水、公共供水及自建供水设施三方面的数据统计结果,探讨了山西省用水、用水需求及今后发展趋势,提出今后城镇供水工作重点,为山西省合理开发利用水资源提供了科学建议。     

The development of a speed zoning knowledge-based system

This paper describes how an expert system shell was used to create a knowledge-based system for speed zone determination. Speed zoning must be rational and consistent if it is to contribute to a speed management programme. The development, within a traffic authority, of speed zoning processes and decisions necessarily falls to a small number of experts who are often confronted with conflicting pressures from a range of interest groups. The paper describes the process whereby the knowledge of experts in the speed zoning area was established and developed into a rationale for system rules. The knowledge-based system developed is proving operationally successful, being user-friendly for both the experts for testing and development, and those wishing to use the system for speed zone determination. An outline is then given of the iterative monitoring procedure whereby the system is being ‘tuned’ to match expert decisions.     

Ecological network analysis of an urban water metabolic system: Model development, and a case study for Beijing

Using ecological network analysis, we analyzed the network structure and ecological relationships in an urban water metabolic system. We developed an ecological network model for the system, and used Beijing as an example of analysis based on the model. We used network throughflow analysis to determine the flows among components, and measured both indirect and direct flows. Using a network utility matrix, we determined the relationships and degrees of mutualism among six compartments - 1) local environment, 2) rainwater collection, 3) industry, 4) agriculture, 5) domestic sector, and 6) wastewater recycling - which represent producer, consumer, and reducer trophic levels. The capacity of producers to provide water for Beijing decreased from 2003 to 2007, and consumer demand for water decreased due to decreasing industrial and agricultural demand; the recycling capacity of reducers also improved, decreasing the discharge pressure on the environment. The ecological relationships associated with the local environment or the wastewater recycling sector changed little from 2003 to 2007. From 2003 to 2005, the main changes in the ecological relationships among components of Beijing's water metabolic system mostly occurred between the local environment, the industrial and agricultural sectors, and the domestic sector, but by 2006 and 2007, the major change was between the local environment, the agricultural sector, and the industrial sector. The other ecological relationships did not change during the study period. Although Beijing's mutualism indices remained generally stable, the ecological relationships among compartments changed greatly. Our analysis revealed ways to further optimize this system and the relationships among compartments, thereby optimizing future urban water resources development.     

Expert system for selecting and prioritizing projects for handling urban water supply crises

ABSTRACT

The water supply crisis (UWC) has affected various cities around the world. The variability of possible causes, the many viable alternatives to UWC management and methodologies for selecting these alternatives, as well as local government’s economic and technical constraints make the problem complex. The aim of this paper is to help select a set of alternative solutions suitable for the UWC problem. The proposed methodology comprised the following steps: (1) theoretical foundation, (2) planning the expert system (ES) to be built, (3) formal knowledge explicitation, (4) knowledge coding, (5) evaluation and adequacy of ES and (6) application of ES to real-life UWC cases. The main result was a computational decision support system, called UWC-ES. The conclusion was that UWC-ES behaved as a computational tool that reasonably reproduces knowledge from various human experts with acceptable applicability, and considering the possibility of using it in other cases.     

人均综合用水量法在西南城市中的应用探讨

科学的需水量预测是城市水源规划和供水工程建设的重要依据。结合实例对我国西南某城市总体规划中市域范围需水量预测方法进行了探讨,并提出人均综合用水量法是预测需水量的有效方法之一。     

城市供水系统抗震防灾规划研究

基于传统理论,结合城市防灾规划的思想研究城市的供水系统防灾规划措施,对城市大震后用水量的估算进行了分析,就如何确定城市供水系统防灾管网作了探讨,提出了加固整修供水设施和制订应急方案应遵循的三个原则,以确保震后做好应急供水工作。     

配水系统中水质监测点的优化布置

对常规水质监测和突发性污染事故水质监测中有代表性的水质监测点布置方法进行了回顾,阐述了各种选址方法的优缺点.在此基础上,对水质监测的发展前景进行了展望,认为各种模型在实际应用中仍需要不断完善.     

给水系统可靠性的确定方法与发展

简要介绍了给水系统中管网和水厂两部分研究者所使用的传统确定系统可靠性的方法和最新发展，并对各种方法进行了简单的比较，同时概要介绍了管网可靠度问题在模型中的实现。     

扬州市区域给水系统规划

指出城市给水系统规划是城市规划的重要组成部分,通过对扬州市区域给水系统的现状进行研究,对扬州市水量、水源、水厂及管网进行了规划,从而使扬州市区域给水系统能够更加适应城市发展的需要。     

基于集对分析的供水管网漏损预测模型

探讨了集对分析法在供水管网漏损预测中的实现途径,从同、异、反三个方面度量漏损预测样本与历史样本的相似性,建立了基于集对分析的漏损预测(SPA-LF)模型。应用结果表明,SPA-LF对预测过程不确定性的描述较为详细,供水管网漏点数及漏损频率预测结果均显示出SPA-LF模型的有效性,减小了预测过程的不确定性,与灰色系统模型、指数平滑模型及神经网络模型预测结果相比,SPA-LF模型取得了满意的预测精度。SPA-LF模型计算简单,使用方便,可为供水管网的维护及管道更新提供决策支持。     

某矿井供水系统设置方案选取

根据矿井的水源情况、地形条件以及各用水对象的水质标准,对矿井供水系统及相关设施的设计进行了论述,并结合相关参数选取供水装置和设置供水系统的建、构筑物,以确保用水安全、可靠。     

住宅给水系统中按户计收水费技术探讨

针对目前自来水公司“抄总表计费，居民按每户装设的分表分摊水费”的收费方式，已不能适应每户居民按实际用水量付费要求的现状，介绍了设计，管理体制，经济核算等诸多方面的情况，从技术方面，分析了旧住宅给水系统在运行中的弊端，从而提出改进管道系统设计在每户装表，远程抄表等方面按户计收水费的技术措施。     

城市理水景观系统整体协同发展的理想模式

根据目前城市理水的变化趋势和发展动向,构建了城市理水景观系统整体协同发展的理想模式,将水景观规划、水环境保护、水生态恢复、水工程建设、水文化传承与水经济开发等涵盖其中,为水景观的规划设计提供了一定的理论与实践指导和支持。     

基于Web的远程故障诊断系统在Linux下的实现方法

提出基于Web的远程故障诊断系统在Linux下的实现方法，克服了在传统Windows下大部分源代码未公开所带来的某些局限性和不透明性，易于管理和维护，具有优良的扩展开发性，系统所用到的软件大多为免费开放型，节约了成本。该系统中采用了BP神经网络模型，并将数据库操作的程序源代码以JavaBeans的形式封装，既隐藏了复杂的操作，又解决了安全性的问题。     

城市给水工程自动化系统设计

城市给水工程自动化系统的建设有其必要性；目前，国内给水自控系统采用最多的是由工业计算机＋PLC＋自动化仪表组成的多级分布式计算机测控管理系统；介绍了给水工程自动化系统构成原理和设计实施方案，阐述了企业信息网络概念、软件组成、功能以及自动化设备选型原则；展望了给水自动化发展方向及应用前景。     

利用管网叠压（无负压）供水设备改造供水系统

以广州某学院供水系统改造为例,介绍了该校原有供水系统的组成,在对供水系统的改造形式进行研究分析的基础上,阐述了供水系统的具体改造方法,并指出使用叠压（无负压）供水设备应注意的事项,从而为今后类似改造工程积累经验。