Water Resources Development: A Balanced Approach

Customers, the public generally, the water industry, its regulators and the government are aware that water can be a scarce and costly product. Resource planning and development must increasingly be viewed as a combined package of water efficiency in (a) use, (b) metering and tariff policy, (c) leakage reduction, and (d) physical schemes.
Droughts, fears over possible climate change, concerns about resources and the environment, a greater awareness of the role and costs of the water industry and statements by the Department of the Environment, the Office of Water Services, and the National Rivers Authority have added weight to this sensible shift in emphasis.
However, society needs reliable water supplies and cannot completely rely upon the uncertain impact that demand side-measures may bring about – nor, even where achieved and cost-effective, on the important savings in losses. New resource schemes can take many years to implement. Therefore, in order to ensure adequate and reliable supplies, plans for new schemes must be brought to a state of readiness, and, in many cases, implemented.     

中国城市规划三十年（1978-2008）纵览

本文通过把改革开放30年以来中国城市规划的发展历程大致分为恢复重建、摸索学习、加速推进、调整壮大、反思求变和更新转型等六个阶段,阐述了城市规划是如何摆脱计划经济束缚、走向市场经济并在实践中发展的,以及城市规划的任务是如何在资本注入和土地制度改革的推动下逐渐显现出宏观调控和建设引导控制作用,并进而适应多变和多元的发展形势,向和谐社会、多值决策和科学发展迈进的。     

Influence of pH and TOC concentration on Cu,Zn, Cd,and Al speciation in rivers

Dissolved ( < approximately 4 nm, dialysis in situ), colloidal ( < 0.45 microm filtered, minus dissolved) and particulate (total, minus < 0.45 microm filtered) concentrations of Cu, Zn, Cd, (Al) in eight (three) mining polluted rivers were determined by atomic absorption spectrometry (flame and graphite furnace). The metal size distribution in the rivers was compared to pH, Ca concentration, alkalinity, conductivity, and total organic carbon (TOC). Data plots based on the present and other studies also yielded information about the interrelations between TOC, pH and metal adsorption in rivers and lakes. Less than 10% of Cu, Zn, and Cd were sorbed on particles or colloids in two rivers with average pH at 3.1 and 5.1, whereas 46%, 21%, and 21% of Cu, Zn, and Cd, respectively, occurred in sorbed form in six pH neutral rivers. In three pH neutral rivers, on average 55% of Al was in colloidal form, whereas the dissolved and particulate fractions were 21% and 23%, respectively. Our data combined with data from similar studies support conclusions from other research suggesting that the percent fraction of metals adsorbed on particles rises steeply from almost zero to nearly 100% within a narrow and element specific pH range. Changes in TOC concentration seem capable of shifting the pH to % metal absorption curves in the order of one pH unit.     

A House is not a Home: The Housing Experiences of African and Caribbean Mothers Living with HIV

HIV-positive mothers living in Toronto, ON, face myriad economic and social challenges that put them at risk for housing instability and homelessness. These challenges are exacerbated for mothers from African and Caribbean communities as they navigate a web of shelter, housing, health care and social care systems that do not adequately address their social positioning as HIV-positive and racialized mothers. To date, there is a dearth of research that has taken a cultural, ethnoracial and gendered lens to explore these issues, and consequently, little is known about their experiences of housing instability as it intersects with issues related to motherhood, poverty, sexism, racism, immigration status and HIV-related stigma and discrimination. This paper presents findings from the HIV, Housing and Families community-based research study and highlights the unique and complex housing issues African and Caribbean mothers facing by living with HIV in Toronto. Implications for policy and practice are also discussed.     

Environmental affordances and children’s needs: Insights from child-friendly community streets in China

With rapid urbanization in China, an increasing building density has squeezed the urban public space. Community streets are occupied by motor vehicles or other functions, and can no longer sufficiently support children to carry out safe and independent activities. As an important space for children’s daily natural contact and social activities, the lack of the spatial function of streets results in a decline in children’s subjective initiative and social abilities. The United Nations has stressed the importance of community as the basic unit of space for children’s daily activities in building child friendly cities. It is urgent to reshape child-friendly community streets and support children’s healthy growth. Integrating previous research results on affordance theory and design, children’s growth and environment, and street-game spaces, this study focuses on investigating 23 community streets in four residential communities in Nanjing through questionnaires, interviews, observations, and other methods. Then, from the perspective of cognitive affordance, functional affordance, and social affordance, it analyzes the behavioral possibilities provided by the environment and the needs of the children-user group. Finally, from the perspectives of openness and security, preference and diversity, positive and negative, and reality and potential, it proposes a method to assess the existing environment. This study aims to extract the significant characteristics of the built environment that effectively support and promote children’s outdoors activities, and explore the design strategy of improving street space sharing through optimizing space elements and structure at the medium and micro levels, so as to respond to multiple goals including livable city development from the perspective of child friendliness. This study also tries to change the logical way of design thinking and provide an eco-psychological perspective on how to build a child-friendly community.     

我国绝缘子的发展现状及应考虑的问题

介绍了我国交直流悬式瓷、玻璃和复合绝缘子以及变电站和换流站支柱瓷、复合绝缘子和空心瓷、复合绝缘子及套管制造技术的发展历程和技术水平。并结合我国绝缘子的运行经验、制造技术水平以及对技术的认识,提出了不同类型绝缘子在制造、设计、选型、运行方面应考虑的问题及建议。如:330 kV及以上支柱瓷绝缘子应采用等静压干法成型工艺;制造企业应控制悬式瓷和玻璃绝缘子的铁帽、绝缘件和水泥胶装剂机械强度的分散性;160 kN、210 kN、300 kN、400 kN、530 kN机械强度等级的绝缘子,应分别采用φ24、φ24或φ28、φ30、φ34或φ38、φ38或φ40芯棒制造绝缘子。超高压和特高压可选该系列中芯棒较大值。不能在同一电压等级采用同一直径的芯棒来制造不同机械强度等级的绝缘子。c级及以下污秽等级复合绝缘子的爬电系数(C.F)不大于3.2;d级及以上污秽等级爬电系数(C.F)不大于3.5;e级及以上污秽等级爬电系数(C.F)不大于3.8;等。     

谈混凝土的裂缝成因及治理措施

采用理论与实践相结合的形式,对混凝土的裂缝进行分类总结,并就混凝土原材料、配合比设计、施工工艺、温差、养护条件等方面进行探讨,分析混凝土结构裂缝的影响因素及产生原因,从而提出混凝土裂缝的合理防治措施及治理方法,确保整个工程质量的安全性、耐久性、适用性。     

预应力锚索应力测量误差的试验研究与对策

了解锚索应力状态时,锚力计示值与千斤顶示值之间普遍存在着较严重的不匹配现象,通过室内外试验和工程数据分析的汇总分析,得到这种不匹配现象主要由仪器设备使用错误及数据错误、测量仪器误差、构件误差及安装误差等施工误差、锚索张拉及锁定时应力损失等原因造成。把千斤顶示值和锚力计示值有机结合,通过现场试验建立两者示值之间的对应关系,能够对锚索的真实应力状况有个较为全面的、准确的了解。     

景观延续与重塑的人文之道——记安亭中学绿化环境改造更新

校园作为城市公共设施体系中的重要组成部分,对人们的社会生活和精神文明起着重要的影响、教育、服务作用。结合安亭中学的景观改造工程实例,从校园的区位环境因素、历史文化积淀、园内景观现状等方面,分析了改造的必要性,改造工作的原则及人文理念的改造方法,重点阐释了对原有历史和景观的发现、挖掘、保护、改造和再利用。通过简洁、现代的手法,把新景观融入校园的建筑环境、历史环境和人文环境之中,重建具有视觉、生态和文化三重效益的校园景观,把校园环境变成凝固的诗、流动的画、无言的歌,从而达到"润物细无声"的效果。     

TREX: spatially distributed model to assess watershed contaminant transport and fate

Contaminant releases from upland areas can have adverse water quality and stream ecology impacts. TREX (Two-dimensional, Runoff, Erosion, and Export) is a spatially distributed, physically-based model to simulate chemical transport and fate at the watershed scale. TREX combines surface hydrology and sediment transport features from the CASC2D watershed model with chemical transport features from the WASP/IPX series of water quality models. In addition to surface runoff and sediment transport, TREX simulates: (1) chemical erosion, advection, and deposition; (2) chemical partitioning and phase distribution; and (3) chemical infiltration and redistribution. Floodplain interactions for water, sediment, and chemicals are also simulated. To demonstrate the potential for using TREX to simulate chemical transport at the watershed scale, a screening-level application was developed for the California Gulch watershed mine-waste site in Colorado. Runoff, sediment transport, and metals (Cu, Cd, Zn) transport were simulated for a calibration event and a validation event. The model reproduced measured peak flows, and times to peak at the watershed outlet and three internal locations. Simulated flow volumes were within approximately 10% of measured conditions. Model results were also generally within measured ranges of total suspended solid and metal concentrations. TREX is an appropriate tool for investigating multimedia environmental problems that involve water, soils, and chemical interactions in a spatially distributed manner within a watershed.