Transition to a water-cycle city: sociodemographic influences on Australian urban water practitioners' risk perceptions towards alternative water systems

Transition to a sustainable water future such as the water-cycle city will necessitate shared, diversified risk management, which acknowledges the subjective risk perceptions of all stakeholders, including water practitioners. Such risk perceptions might vary with personal and professional characteristics. This study explores the influence of these characteristics on Australian urban water practitioners' risk perceptions of four alternative water systems, varying in scale of operation and water source, i.e. seawater desalination, indirect potable reuse, sewer mining and stormwater harvesting systems. Analysis of sociodemographic and risk perception data (N = 620) collected from a national online survey revealed that risk perceptions can vary with age or number of years' experience, educational qualification, stakeholder group and area of work within the water sector, reflecting different communities of practice. To facilitate adoption of a suite of sustainable urban water systems, these different risk perceptions must be identified, acknowledged and managed. Targeted social learning through experimentation is a useful approach to achieve this.     

Statistical analysis of public perceptions of water infrastructure sustainability in shrinking cities

Population contraction has afflicted a number of U.S. cities, presenting problems as the infrastructure becomes overbuilt for shrinking populations. Civic authorities have options to make infrastructure sustainable in light of urban decline including decommissioning or raising service costs to sustain existing infrastructure. This paper conducts a survey and statistical analysis of public opinions towards water infrastructure decommissioning and raising costs in U.S. shrinking cities, to identify groups likely to oppose these alternatives and hamper sustainability efforts. The analysis found a range of socio-economic factors affecting residents' likelihood of opposition and that their impacts vary considerably across the population. One critical finding is that only approximately 50% of respondents are aware their city is shrinking and that these residents have significantly different views on sustainability options. The statistical findings provide important initial information on how residents are likely to respond to policies seeking to right-size infrastructure with regard to population.     

Recognising barriers to implementation of Blue-Green Infrastructure: a Newcastle case study

There is a recognised need for a fundamental change in how the UK manages urban water and flood risk in response to increasingly frequent rainfall events coupled with planned urban expansion. Approaches centred on ‘living with and making space for water’ are increasingly adopted internationally. Nonetheless, widespread implementation of Blue-Green Infrastructure (BGI) is currently hampered by barriers that impede uptake and innovation. We investigate the barriers to implementation of BGI in Newcastle, UK, through a series of semi-structured interviews with professional stakeholders. We identify and categorise 17 types of barrier and identify targeted strategies to overcome the dominant barriers. We recommend promotion of BGI’s capacity to meet the objectives of multiple organisations and Local Authority departments, in addition to managing urban water. We conclude that strong business cases, supported by monetised evidence of benefits, and collaborative, inter-agency working could advance implementation of BGI within the current flood risk management legislation.     

城市水系统规划存在问题及解决对策初探

列出了目前城市水系统规划存在的问题并对其根本原因进行了分析;提出了从城市健康水循环和水资源持续利用的角度来构建新的城市水系统,可有效地协调城市流域的用水问题;同时针对新城市水系统规划需要研究的内容和急需解决的问题进行了初步探讨,为城市水安全提供一个可靠的保障。     

The management of urban surface water drainage in England and Wales

Partly in response to the UK flooding events of 2007, a number of reports have recently been produced addressing the legislative, administrative, institutional and structural practices that are required to improve urban surface water management and hence reduce future flooding incidents and associated pollution impacts. This paper addresses the principal barriers to progress that have been identified and how these are likely to be overcome. Improved and integrated organisational structures, process and procedures are required and relationships between flood risk management and water quality need to be addressed at regional, area and local levels as well as legislative clarification on surface water discharges. Nontechnical aspects will need to be supported by new modelling approaches for flood risk prediction at both local and catchment scale with effective communication systems and tools being developed and implemented for full and effective stakeholder participation.     

Towards sustainable urban water management: A critical reassessment

Within the literature, concerns have been raised that centralised urban water systems are maladapted to challenges associated with climate change, population growth and other socio-economic and environmental strains. This paper provides a critical assessment of the discourse that surrounds emerging approaches to urban water management and infrastructure provision. As such, ‘sustainable urban water management’ (SUWM) concepts are scrutinized to highlight the limitations and strengths in the current lines of argument and point towards unaddressed complexities in the transformational agendas advocated by SUWM proponents. Taking an explicit infrastructure view, it is shown that the specific context of the urban water sector means that changes to infrastructure systems occur as an incremental hybridisation process. This process is driven by a range of factors including lock-in effects of legacy solutions, normative values and vested interests of agents, cost and performance certainty and perceptions of risk. Different views of these factors help explain why transformational agendas have not achieved the change SUWM proponents call for and point to the need for a critical reassessment of the system effects and economics of alternative service provision models.     

Conservation rates: the best 'new' source of urban water during drought

In the United States, water conservation-oriented rates (WCOR) are an increasingly vital tool for promoting water conservation and mitigating urban drought. Our models prove that one type of WCOR, drought demand rates (DDR), can produce with minimal regulation the quadruple objectives of conservation rates: (1) improving efficiency; (2) providing revenue neutrality; (3) assuring distributional equity and (4) guaranteeing the conservation of water. We demonstrate that such rates can also reduce days that urban streams drop below 'critical flow' levels, providing a voice for nature. Our study is situated in northern New Castle County (NCC), Delaware (DE), USA, and the lessons garnered have relevance for industrialized communities seeking a 'soft-path' to drought mitigation.     

The evolution of urban water systems: societal needs,institutional complexities,and resource costs

ABSTRACT

Urban water systems provide critical services to meet the supply, sanitation, and drainage needs of urban societies. Evolving needs have resulted in increasingly expansive infrastructure, raising questions about the sustainability of such large infrastructure investments. In this study, we demonstrate the historical interplay between growing urban water needs, the services developed to meet them, and their total resource cost. We hypothesize that needs evolve hierarchically, with predictable outcomes in the form of service progression. To test this hypothesis, we use a suite of metrics at the US national scale indicative of our proposed hierarchy levels. At the city scale, we assess the cost implications of this progression of services. We use the emergy framework to quantitatively reconstruct the historical resource requirements of supply, sanitation, and drainage services and show how evolving needs lead to mounting resource costs. Lastly, we discuss implications of continually increasing complexity for meeting future water needs.     

城市社区火灾风险分析和管理

分析了在城市社区开展火灾风险分析和评估的重要性,介绍了城市社区存在的火灾危险性和消防安全问题,社区火灾风险分析的步骤,探讨制订城市社区火灾风险管理和控制规划需要考虑的因素,为提高城市社区消防安全管理、保证居民生命和财产安全提供参考.     

污水厂再生水用于城市绿化的健康风险评价研究

针对深圳市3个污水处理厂再生水水体中的有毒有害化学物质,采用基于蒙特卡罗( Monte - Carlo)模拟的概率统计方法对再生水回用于城市绿化途径所造成的人体健康风险进行了定量评价.结果表明,深圳市A、B、C污水处理厂再生水中化学物质所致人体终身健康风险与个体健康风险均远小于国际公认可接受的最大风险水平,各污水厂的再生水可直接回用于城市绿化.     

The influence of context and perception when designing out risks associated with non-potable urban water reuse

Perceptions and cognitive bias in relation to reuse water can influence the responses to risk and reward. Much has been written on community perspectives and risk perceptions with regard to recycled water for non-potable use. This paper is distinct in that it focuses on the scheme proponents and those involved in designing and delivering schemes. An analysis of five case studies in Australia across a range of diverse settings revealed that the levels of treatment for various end-uses were in excess of the Australian Guidelines for Water Recycling. The evidence shows that the water industry has a fairly narrow view when identifying risks, and has an insurance type response to mitigating the risk. The overarching drivers for this are either the mitigation of the perceived risk associated with using reuse water, or the lack of an adaptive response to changes in the circumstances.     

谈临汾市再生水资源的发展与利用

对临汾市面临的水资源问题进行了分析,指出在城市中推行再生水利用是一个很有效的途径,是解决水资源短缺的好方法,是缺水城市势在必行的重大决策,论述了再生水利用的可行性及实施方案,并提出了合理化建议。     

城市轨道交通项目融资风险管理方法探讨

在城市轨道交通项目融资风险辨识的基础上,介绍了评估矩阵法、层次分析法及模糊综合评判法和城市轨道交通项目融资风险的估计和评价方法,并对风险管理有效控制进行了探讨,为城市轨道交通项目融资风险管理提供了一定指导。     

城市水系与江南地区城市特色的传承--以湖州市南浔区新中心区城市设计为例

本文主要以湖州市南浔区新中心区城市设计为例,探讨了在当今城市水系不断衰退和城市特色不断丧失的背景下城市水系与城市特色的关系以及如何在城市水系方面传承江南地区城市特色的对策措施。     

Validating a rapid assessment framework for screening surface water flood risk

This research evaluates performance of a rapid assessment framework for screening surface water flood risk in urban catchments. Recent advances in modelling have developed fast and computationally efficient cellular automata frameworks which demonstrate promising utility for increasing available evidence to support surface water management, however, questions remain regarding trade‐offs between accuracy and speed for practical application. This study evaluates performance of a rapid assessment framework by comparing results with outputs from an industry standard hydrodynamic model using a case study of St Neots in Cambridgeshire, UK. Results from the case study show that the rapid assessment framework is able to identify and prioritise areas of flood risk and outputs flood depths which correlate above 97% with the industry standard approach. In theory, this finding supports a simplified representation of catchments using cellular automata, and in practice presents an opportunity to apply the framework to develop evidence to support detailed modelling.     

Exogenous pressures and probabilistic assessment of risk and vulnerability of urban water systems in Ghana

ABSTRACT

Risk and vulnerability assessment of urban water systems can be extended to include several components. This work formulates a probable quantitative assessment of risk and vulnerability of urban water system based on climatic conditions and urban population growth. Climate change scenarios and population projections are used to estimate susceptibility to water supply systems’ risk and vulnerability. Quantile regression was used to establish the exponent correlation between the climate variables and population; and evaluate their consequential influences on urban water supply systems. We complemented the analysis with a probabilistic model to assess the robustness of urban water system that depends wholly on the climate for freshwater source. The study established that Climatic conditions, though uncertain, point to freshwater deficiency in the future. Moreover, population trends project a higher urban population thereby increasingly lowering water per capita and subsequently leading to doubtful urban water system’s resilience to the exogenous pressures.     

A decision support model to aid the management of crises in urban water supply systems (the UWC-MODEL)

The objective of this study was to develop a model for crisis management in urban water supply systems, able to assist the decision-making process to deal with the urban water crisis (UWC) by those responsible for these systems. The research methodology used for model development consisted of the following steps: (1) development of a decision support model for cases of crises in urban water supply systems (UWC-MODEL); (2) performing the sensitivity analysis of the UWC-MODEL; (3) verifying the UWC-MODEL; and (4) application of the UWC-MODEL. Different levels (socio-economic, management, urban, environmental and cultural) of the UWC problem were considered in the UWC-MODEL. It was based on the similarity between a weak UWC situation (or absence), strong UWC situation (or severe) and the actual case. Results of the application of the UWC-MODEL to the Administrative Region of Brasilia, in the Federal District of Brazil, indicated that actions related to cultural and environmental levels demonstrated a greater contribution for combating UWC. Actions such as environmental education programs, water conservation programs, and use of water saving equipment, were indicated by the UWC-MODEL to solve the UWC problem in this application to the real case.     

The water supply is fine: decision‐maker perceptions of water quantity and supply‐side management

Years of research have called for more science to be integrated into water management decisions and for a shift from supply‐side to demand‐side management; yet, there remains a strong emphasis on supply‐side approaches and in many areas limited attention to hydrological data. A survey and interviews with decision‐makers in western North Carolina reveal that there is only low‐level concern about water quantity, and this drives a continued emphasis on supply‐side management and no perceived need for hydrological data. The historical realities of low demand and abundant water have generated a perception of ‘water supply’ as disconnected from physical, hydrological systems and allowed for ad hoc decision‐making processes to prevail. The lack of well‐established processes may, ironically, provide significant opportunities for employing collaboration among researchers and decision‐makers to develop policies and processes that integrate data into making water management decisions and thus prompt increased attention to water demand.     

Sustainability of water management in Zaragoza city

This paper reviews the significant developments in water management that have occurred in Zaragoza, Spain in recent years. Action to achieve more sustainable water management was initiated by a local nongovernmental organisation (Ecodes) persuading and assisting the municipality to improve its delivery performance. Key successes, made by all sectors of the community, include the reduction of water use in the City by 1600 ML/year since 1995 despite significant population growth. The sustainability of the campaign is assessed within a recently devised PESTER framework which systematically addresses the key political, economic, social, technical, environmental and regulatory factors. This highlighted that a workable tariff system has now been achieved which is arguably fair to all, and that a balance has been achieved between local and nationally applicable water law. The main conclusion is that in order to achieve significant progress, it is vital to harmonise the energies, finances and above all commitment of all the main stakeholders.     

我国城市水资源管理及其发展趋势

阐述了我国城市水资源的主要特征,从水资源短缺、时空分布、污染、供需矛盾、管理等方面分析了当前城市水资源管理中存在的问题,并对城市水资源管理的研究范畴和发展趋势进行了探讨,以最终实现城市水资源的可持续利用和发展。