Multicriteria decision-aid method to evaluate the performance of stormwater infiltration systems over the time

Nowadays, stormwater infiltration systems are frequently used because of their ability to reduce flows and volumes in downstream sewers, decrease overflows in surface waters and make it possible to recharge groundwater. Moreover, they come in various forms with different uses. Despite these advantages the long term sustainability of these systems is questionable and their real performances have to be assessed taking into account various and sometimes conflicting aspects. To address this problem a decision support system is proposed. It is based on a multicriteria method built to help managers to evaluate the performance of an existing infiltration system at different stages of its lifespan and identify whether it performs correctly or not, according to environmental, socio-economic, technical and sanitary aspects. The paper presents successively: the performance indicators and the way they were built, the multicriteria method to identify if the system works properly and a case study.     

Multicriteria evaluation tools to support the conceptual design of activated sludge systems.

During the past decade the pressure of the whole spectrum of stakeholders has increased considerably leading the consideration of different types of objectives, i.e. economical, technical, legal and environmental, into the process design efforts. Thus, the traditional design approaches should turn into more complex assessment methods including different types of objectives in order to conduct integrated assessments. The objective of this paper is to present and discuss the usefulness of three evaluation tools, based on multicriteria decision analysis, to support the conceptual design of activated sludge systems These support tools consist of: i) preliminary multiobjective optimization, where the most promising options (those located near to the optimum) are compared based on the results of dynamic simulation, ii) identification of strong and weak points for each option by means of classification trees and the subsequent extraction of knowledge-based rules, and iii) evaluation of the trade-offs between a certain evaluation criteria and the overall process performance through the integrated application of mathematical modelling and qualitative knowledge extracted during the design process.     

Long-term hydraulic and pollution retention performance of infiltration systems.

Infiltration techniques are now widely used to manage stormwater in urban areas. These techniques are used and recognized around the world for their many advantages, such as decreasing stormwater flow in sewer systems and recharging groundwater. But numerous cases of infiltration devices that failed after a few years of operation are still being reported. This study, which is based on site-monitoring of operational infiltration systems, is part of the Field Observatory for Urban Water Management (OTHU). The main goals of this study are to improve knowledge of long-term hydraulic behaviour, especially as concerns the clogging speed and the quality of the runoff. This article will present the site, the monitoring process and the model that will be used to assess the hydraulic behaviour. First results of the calibration of the model show that the model is able to assess the hydraulic behaviour of the basin when it is clogged (average value of hydraulic resistance 17.1 h) and when it has been scraped (hydraulic resistance less than 3.8 h). However, further data are needed in order to validate the model. We also show that the experimental setup is well designed to assess the water volume and the sediment brought to the basin with low uncertainties.     

亚行项目融资渠道及管理程序

亚行贷款项目融资是我国利用外资的资源主要渠道之一。本文简要介绍了亚行融资项目的类型、融资渠道和对亚行内部项目管理程序。     

地下渗滤系统与管理的探索

有效管理是保证地下渗滤系统达到保护公众健康和环境资源的关键。对系统设计全过程的各环节:规划、目标、场址评估、设计、施工、运行和维护的管理要求从技术层面作全面探索。指出管理关键点及管理不善可能造成的风险。总结有效管理的十大要素应在今后实践中逐渐充实完善。     

Integrated modelling for the evaluation of infiltration effects.

The objective of the present study is the estimation of the potential benefits of sewer pipe rehabilitation for the performance of the drainage system and the wastewater treatment plant (WWTP) as well as for the receiving water quality. The relation of sewer system status and the infiltration rate is assessed based on statistical analysis of 470 km of CCTV (Closed Circuit Television) inspected sewers of the city of Dresden. The potential reduction of infiltration rates and the consequent performance improvements of the urban wastewater system are simulated as a function of rehabilitation activities in the network. The integrated model is applied to an artificial system with input from a real sewer network. In this paper, the general design of the integrated model and its data requirements are presented. For an exemplary study, the consequences of the simulations are discussed with respect to the prioritisation of rehabilitation activities in the network.     

上海市排水小区地下水渗入量研究

介绍了排水小区地下水渗入量测试的基本方法。采用夜间最小流量法和用水量折算法 ,对上海市代表性排水小区地下水渗入量进行了实测和分析 ,确定了不同类型排水小区的渗入量范围。对区域渗入量试验中需要关注的问题进行了研讨。研究成果为推动渗入量研究、改进高地下水位地区排水系统的设计、维护与管理提供了依据     

Wastewater reuse in central Asia: implications for the design of pond systems.

The paper examines the potential of waste stabilisation ponds to provide water for reuse in extreme continental climates such as those of central Asia, where precipitation is low and summer evaporation rates are high. A simple model is used to predict water availability, BOD and faecal coliform removal for different configurations and operating regimes. The results show a significant proportion of flows could be saved for irrigation or river and aquifer replenishment: if current standard designs can be modified for these climates, the outcome is likely to be both more robust and more flexible in terms of types of reuse. The paper concludes with three case studies of evaporation pond systems in Kazakhstan, assessing their potential for conversion to full biological treatment systems for water conservation and reuse.     

亚行贷款项目中资金支付管理程序分析

随着中国经济的不断发展及改革开放的不断深入,国际金融组织对中国水利行业的影响也不断加深,每年亚洲开发银行对中国水利行业的投资近2亿美元.本文根据亚行贷款松花江洪水管理行业项目的资金管理经验,对亚行贷款项目中资金支付管理进行讨论.     

Efficient design and operation of a data acquisition system for pressurized pipeline systems.

The unsteady flow analysis of pipeline systems provides useful guidelines for implementing data acquisition components such as data filtering ranges, sensor locations and sampling frequencies. A theoretical integration among hydraulics, free vibration analysis and signal processing is proposed for a comprehensive approach aiming at enhanced design and operation of data acquisition system. Transient analysis is performed to extract flow variation by a valve modulation in a pipeline system. Frequency transformation analysis is developed to convert pressure variations between time domain and frequency domain. Free vibration analysis provides spatial distribution of impedance characteristics and pressure variation for determining optimum sensor location. A real-time filter can be designed to secure valid signals of any particular unsteady event. Hypothetical and experimental applications show that the proposed method has potentials of the leakage detection of a pipeline system as well as an efficient design of data acquisition system.     

Non-deposition self-cleansing design criteria for drainage systems

Self-cleansing is a substantial aspect of the drainage systems in which it is desired to minimize the sediment deposition that can cause channel blockage and surcharge early overflows. In the conventional self-cleansing design criteria of drainage systems, a single value of velocity or shear stress is used based on experience. In the recent decades rather than using a single value, non-deposition design concept has been further modified to develop self-cleansing models based on higher number of parameters considering flow, fluid, sediment and channel characteristics. However, non-deposition self-cleansing models have been mostly developed for circular channels, and none of the models considers yet the effect of channel cross-section although some models take into account the pipe diameter, hydraulic radius and cross-section area as independent variables. In this study, a self-cleansing model considering the effect of cross-section by a shape factor available in the literature is developed to determine the non-deposition particle Froude number for bed load sediment transport. The model is developed using experimental data of circular, rectangular and U-shape channel cross-sections from the literature; and data of trapezoidal channel cross-section from experiments carried out in this study. For validation of the model, data collected in this study is used together with four different sources of data taken from the literature. Validation of the model for each cross-section data shows its wide range applicability in terms of different channel cross-sections.     

黄湓闸计算机监控系统设计及运行管理

本文对黄湓闸计算机监控系统设计方案、工作原理、系统功能、系统实施难点及运行中存在的问题进行了分析,对监控系统软件中预留的远程调度接口方案进行了比选,对类似工程具有借鉴意义.     

国际水电工程的机电设计与工程管理

通过对国际水电工程机电设计特点的分析,提出了国际水电工程设计过程中存在的问题,并对各问题进行了初步的探讨与分析,提出解决问题的思路和建议。     

谈中小水电项目建设程序管理——以贵州中小水能资源开发利用现状为例

分析近年来贵州省中小水电资源开发建设活动中存在的因项目建设程序管理不规范所造成的水能资源开发无序、资源浪费以及工程事故隐患等诸多问题,依据水利工程建设管理有关法律法规,从项目建设管理角度进一步探讨了中小型水电项目建设管理的基本程序。图2幅。     

Performance comparison between infiltration and non-infiltration type of structural stormwater treatment systems

The study was constructed to monitor representative inflow and outflow from infiltration and non-infiltration type best management practice (BMP) sites developed at a university campus, allowing the determination of overall performance efficiency in terms of runoff reduction and pollutant removal. Based on the monitored storm events, the runoff and discharged volume and flow rates exhibited high positive correlations with total rainfall depth (p<0.001). Findings revealed that as the total rainfall increases, the amount of volume reduction and pollutant removal decreases for both types of BMP. Infiltration BMP showed a higher ability in treatment performance especially during small storm events than non-infiltration type; however, the differences were not significant. Pollutant removal rates of infiltration type were in the range of 70-90% while between 35 and 80% for the non-infiltration type for storm events with less than 10 mm rainfall depth. Average volume reductions were 71 ± 33% and 32 ± 32% for the infiltration and non-infiltration type, respectively. The ratio of the discharge volume was significantly greater than the ratio of discharge pollutant load indicating a high potential for water quality improvement. Design recommendations were provided considering sizing and cost for on-site application of similar BMP designs in the future.     

EPC总承包管理模式下工程设计管理探析

介绍了EPC的概念、EPC工程总承包管理模式的特点;通过工程实例,简要概述了EPC项目设计管理的工作流程,并针对EPC总承包设计的管理重点,提出了在EPC模式下对设计管理工作的一些意见。     

Model description of storage and infiltration functions of infiltration facilities for urban runoff analysis by a distributed model.

Although there have been simulation researches focusing on reduction of stormwater peak flow by introduced infiltration facilities, model simulation of dynamic runoff behavior is still limited for frequently occurring rainfall events with weak intensity. Therefore, dynamic simulation was carried out in two urban drainages with infiltration facilities incorporated with a distributed model using two methods for describing functions of infiltration facilities. A method adjusting effective rainfall model gave poor simulation of runoff behavior in light rainfalls. Another method considering dynamic change of storage capacity as well as infiltration rate gave satisfactory estimation of the runoff in both drainages. In addition, assumption of facility clogging improved the agreement between measured and simulated hydrographs in small and medium-sized rainfall. Therefore, the proposed method might be useful for quantifying the secondary effects of the infiltration facilities on groundwater recharge and urban non-point pollutant trapping as well as runoff reduction.     

水资源开发利用与区域经济协调管理模型系统研究

本文以大系统递阶优化控制理论为基础，提出了水资源开发利用与区域经济协调管理的模型系统，针对该模型系统提出了一种新算法，并将所提出的模型系统和算法应用于石家庄地区，结果表明，模型系统对水资源开发利用与区域经济协调管理提供了一种有效方式。