Klimawandel und Urbanisierung – wie soll die Wasserinfrastruktur angepasst werden?

Conventional urban water servicing has successfully provided cities with clean water, sanitation and flood protection. Traditional approaches are unsuited to address future challenges like climate change and modern urban development trends (e.g. migration, aging population, densification). As well as increased risks of water scarcity and flooding, society's demands for urban amenity and healthy waterways in metropolitan areas also challenge these traditional principles of urban water management. It is increasingly recognized that solutions to these challenges will not be purely technological in nature; the socio-institutional contexts will also be critical. However modelling tools to support medium and long-term strategic planning of integrated social and infrastructural dimensions are lacking, leaving decision-makers with untested policy ideas. To identify possible transition strategies to a resilient city, the development of the DAnCE4Water (Dynamic Adaptation for eNabling City Evolution for Water) within the EU FP7 project “PREPARED: Enabling Change” as a strategic planning and decision-support tool is thus proposed. DAnCE4Water allows ‘What-if’ experiments by investigating possible consequences of policies and strategic actions, taking into consideration urban development, climate change, biophysical environment and societal dynamics. This paper presents the concept of the DAnCE4Water tool and its application to an example city's evolution 20 years into the future.     

Defining urban diffuse pollution loadings and receiving water hazard.

The use of unit area loading approaches to address the requirements of the US Clean Water Act (CWA) and the EU Water Framework Directive (WFD) to identify and manage diffuse urban pollution sources is outlined. Issues relating to traditional volume-concentration probabilistic modelling are highlighted and the robustness of total maximum daily load (TMDL) approaches is discussed. A hazard assessment methodology for catchment scale identification of source area pollutant loadings and receiving water ecological impacts is developed based on urban land use activities.     

Model-Supported Impact Assessment for the Water Sector in Central Germany Under Climate Change—A Case Study

Climate change challenges water managers and researchers to find sustainable management solutions, in order to avoid undesirable impacts on water resources, environment and water-dependent sectors. Needed are projections into the future for the main driving forces, the resulting pressures on water resources, and quantification of the impacts. Modeling studies can play an important role in investigating, quantifying, and communicating possible impacts of climate change, with account of uncertainty of the results. However, climate change related impacts and a need for adaptation still play a minor role in current river basin management plans that have to comply e.g. with the EU Water Framework Directive (WFD). One important reason is that climate impact assessment is generally done in research institutes, while management plans are designed by practitioners working in national and regional environmental agencies and water supply companies. Knowledge transfer from science to practice and visa versa is often missing. In the present study, we propose a methodology and a case study for model-supported decision making in the water sector applicable to a participatory water resources planning process. The methodology is applied in a case study investigating climate change impacts on water resources. The case study area is the German State of Saxony-Anhalt, where the task was to develop a climate change impact assessment including possible adaptation measures as basis for a federal adaptation directive.     

Implementation impediments to institutionalising the practice of sustainable urban water management.

It is now well accepted that there are significant challenges to realising the widespread and self-sustaining implementation of sustainable urban water management. It is argued that these challenges are entrenched within the broader socio-political framework, yet often unsuccessfully addressed within the more narrow scope of improving technical knowledge and design capacity. This hypothesis is investigated through a comparative analysis of three independent research projects investigating different dimensions of the water cycle, including stormwater management in Australia and sanitary waste management and implementation of innovative technologies in the U.K. The analysis reveals significant and common socio-political impediments to improved practice. It was evident that the administrative regime, including implementing professionals and institutions, appears to be largely driven by an implicit expectation that there is a technical solution to solve water management issues. This is in contrast to addressing the issues through broader strategies such as political leadership, institutional reform and social change. It is recognised that this technocratic culture is inadvertently underpinned by the need to demonstrate implementation success within short-term political cycles that conflict with both urban renewal and ecological cycles. Addressing this dilemma demands dedicated socio-technical research programs to enable the much needed shift towards a more sustainable regime.     

Public acceptance of recycled water

Recycling water is not new. Yet, there are many examples from around the world of recycled water projects that have failed because of public opposition. This article reviews the literature investigating factors associated with public acceptance of recycled water, as well as publicly accessible reports and case studies, which have developed or tested approaches to increase public acceptance. The article concludes by summarizing the state of knowledge in this area, and advancing key research questions relating to public acceptance of recycled water that urgently need to be investigated.     

长江水资源保护与可持续发展

目前长江水质总体尚好 ,但是局部水域污染严重 ,以有机物污染为主。当前长江流域水污染的主要特点为 :江河水污染特别是干流近岸水域污染未能得到遏制 ;流域内地表水体富营养化严重 ;白色污染未得到有效控制 ;非点源污染问题不应忽视。从长江流域可持续发展角度分别对城市发展、工业发展、农业和农村发展的水环境问题识别其影响 ,提出实现长江水资源可持续利用的关键是统一进行流域的整体环境保护规划 ,重点处理各个区域间的矛盾 ,尽最大可能满足各个区域对环保和供水等的要求 ,同时要进行水资源管理体制、水资源投资体制、水价政策的改革 ,并根据长江流域的具体情况制定 2 1世纪的长江水战略 ,以促进流域经济的可持续发展。     

Water Price Reforms in China: Policy-Making and Implementation

Following the conviction that economic and pricing approaches are an essential addition to conventional command-and-control environmental regulation, China has gradually increased attention to, research on and experiments with the application of economic instruments in urban water management over the past two decades. This paper analyzes the actual application and implementation of economic instruments in Chinese urban water sectors, applying an ecological modernization perspective. Water tariffs in China have increased sharply over this period, increasingly representing full costs and increasing water use efficiency. But implementation of water tariffs does run into problems of unclear responsibilities, poor collection rates and institutional capacities. It is concluded that Chinese style ecological modernization should pay more attention to the institutional dimensions of natural resource pricing policies, if it is to profit from the theoretical advantages of economic approaches in urban water management.     

Tempo-Spatial Analysis of Water Quality in the Three Gorges Reservoir,China, after its 175-m Experimental Impoundment

The Three Gorges Reservoir (TGR) has brought great socio-economic benefits and has had huge effects on the aquatic environment. The large scale and diversity of the TGR result in the variations of the water quality among the mainstream and its tributaries. Comprehensive understanding of the water quality status is crucial for water management and regional development of the TGR. Monthly data of 8 water quality parameters, including potential of hydrogen, biochemical indexes and nutrients indexes, were collected from 14 sampling sites distributed in the Yangtze River and four tributaries. The temporal and spatial distributions of each water quality parameter were presented, and the underlying causes were disclosed. The cluster analysis (CA) and the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) were adopted to analyze and assess the water quality statuses and trend. The results showed that most of the water quality parameters presented significant seasonal patterns due to the seasonality of hydrologic/hydraulic variables. Water quality status and pollution type varied among the mainstream and its tributaries, due to the spatial heterogeneity of geology, geomorphology and anthropogenic activities. NO₃-N, TN and TP were identified as the key pollution indexes, presenting the enriched nutrients in the water body. A large proportion of NO₃-N in the TN (over 80%) was linked to the abuse of chemical fertilizers. The water quality in the TGR cannot always reach natural or desirable levels at several of the sampling sites where development and urbanization are relatively high, such as those near the main urban area of Chongqing or the inflow section of the Wu River. This study is expected to have major implications for water quality analysis and assessment approaches and water environment protection and management at large scales.     

城市节水绿地系统规划研究——以哈尔滨哈西区为例

为了将雨水资源化利用与绿地系统规划相结合给区域节水绿地的建设提供理论依据,最终达到节约城市淡水资源的目的,以哈尔滨市哈西区为切入点,对研究区的雨水资源潜力展开研究;利用GIS地表水文分析技术,将能够收集雨水的区域确定为节水绿地,进而对哈西区的绿地系统进行规划设计。对我国目前的城市雨水资源化利用的现状、研究区的特点及其节水绿地的规划、绿地系统的结构与布局等方面的情况作了介绍。     

Applying water soft path analysis in small urban areas: four Canadian case studies

Water soft paths begin from the vision that future water management has more to gain from reducing demand than from increasing supply. This article reviews three case studies of water soft path analysis in small urban areas in Canada, and one study of an urban planning process incorporating soft path concepts. The analytical studies indicate how communities can avoid the need for expansion of water infrastructure with negligible impacts on lifestyles or livelihoods. The planning study demonstrates that it is possible to introduce water soft paths early in a review, and that this will stimulate more ecologically sensitive thinking among citizens, officials and political leaders. Similar conclusions can be expected from soft path studies in urban areas elsewhere in the developed world.     

Dealing with Uncertainties in Fresh Water Supply: Experiences in the Netherlands

Developing fresh water supply strategies for the long term needs to take into account the fact that the future is deeply uncertain. Not only the extent of climate change and the extent and nature of its impacts are unknown, also socio-economic conditions may change in unpredictable ways, as well as social preferences. Often, it is not possible to find solid ground for estimating probabilities for the relevant range of imaginable possible future developments. Yet, some of these may have profound impacts and consequences for society which could be reduced by timely proactive adaptation. In response to these and similar challenges, various approaches, methods and techniques have been proposed and are being developed to specifically address long-term strategy development under so-called deep uncertainty. This paper, first, offers a brief overview of developments in the field of planning under (deep) uncertainty. Next, we illustrate application of three different approaches to fresh water provision planning under uncertainty in case studies in the Netherlands: a resilience approach, oriented to (re) designing fresh water systems in such a way that they will be less vulnerable, resp. will be able to recover easily from future disturbances; a robustness approach, oriented to quantitative assessment of system performance for various system configurations (adaptation options) under a range of external disturbances, and an exploratory modeling approach, developed to explore policy effectiveness and system operation under a very wide set of assumptions about future conditions.     

Water governance,ecosystems and sustainability: a review of progress in South Africa

It is approaching two decades since South Africa's democratic transformation introduced a visionary approach to water resources management. The earlier challenges of water law reform have given way to the greater undertaking of implementation. This paper reviews progress in relation to 7 of the 10 key challenges of the Africa Water Vision 2025. Progress in many areas has been slow, including establishment of catchment management institutions and implementation of environmental flows. Concerns remain regarding poor water quality and aquatic ecosystem health. A significant threat is the persistent shortage of skilled water professionals.     

引大济湟工程受水区水量分配的重新调整与优化研究

考虑水源可供水量、经济社会需水、生态环境需水等约束条件,建立了区域多目标的水资源优化配置模型,利用GAMS(General Algebraic Modeling System)系统进行求解,重新调整和优化了引大济湟工程受水区水量分配总体格局。进而,估算了工程投资规模,以支撑湟水干流全面建设小康社会和实现东部城市群跨越式发展,为湟水干流城镇化、工业化和产业化发展新战略提供安全的供水保障,并充分发挥和提高引大济湟工程经济社会与生态环境等综合效益。     

Framework for Sustainable Urban Water Management in Context of Governance,Infrastructure, Technology and Economics

Water Resources Management - Administrators of urban water institutions face huge challenges in ensuring water rights and water security of the citizens of ever-expanding cities. The concept of...     

Water governance, resilience and global environmental change - a reassessment of integrated water resources management (IWRM).

Integrated Water Resource Management (IWRM) is gaining increased acceptance among water policy makers and researchers as a way to create more effective governance institutions, leading towards integrated water development solutions for poverty alleviation, while addressing social, economic and environmental aspects of water challenges. However, global environmental change poses fundamental challenges to water policy makers as it implies vast scientific, and hence, policy uncertainty; its implications for international water governance initiatives remain unspecified, effectively hindering dialogue on how current IWRM initiatives should be modified. This paper addresses the lag between our growing understanding of resilient interconnected freshwater resources (and their governance) and the reforms being promoted by policy makers. In particular, there is a need to rethink some of IWRM's key components to better tackle the challenges posed by the complex behaviour of interconnected social-ecological systems and global environmental change.     

The scope of integrated modelling: system boundaries, sub-systems, scales and disciplines.

Integrated modelling has become an urgent issue of urban drainage and wastewater treatment planning. The scope of integrated modelling, system boundaries and disciplines to be involved are addressed in view of future developments and new paradigms in urban drainage, demanding the inclusion of the full urban water cycle. A system analysis is demonstrated to identify relevant sub-systems and components, processes and interactions within the urban water system. The permissibility to exclude subsystems or neglect interactions is evaluated. Integrated modelling of urban water system is characterised as an ambitious task in regard to system complexity, heterogeneous scales and interface problems. The methodical status quo is characterised in preliminary approaches towards integrated modelling. It is concluded that it does not seem promising to create and apply one entity model for the scope of integrated urban water modelling. Instead, the development of adequate and efficient IT frameworks is identified as the key issue of integrated modelling. Harmonising interfaces to facilitate the linking of existing models is presented as the objective of a European research project HarmonlT and the U.S. EPA Multimedia Integrated Modelling System project MIMS.     

Implications of Urban Form on Water Distribution Systems Performance

This paper presents the results of an investigation into the relationship between urban form and the performance of a water distribution system. The effect of new development or redevelopment on the performance of an expanded rehabilitation of the well-known Anytown water distribution system is examined to provide an insight into their interaction, which can be considered along with other aspects of renewal to achieve more sustainable urban areas. A range of urban growth rates, urban form and water efficiency strategies are studied in relation to the system’s key performance indicators of total cost, resilience and water quality. The urban forms considered in this work are compact/uniform, monocentric, polycentric and edge developments. These development patterns are representative of common development approaches widely applied in urban planning. They also correspond to future settlement patterns, based on adopting four future (socio-economic) scenarios so called Policy Reform (PR), Fortress World (FW), New Sustainability Paradigm (NSP), and Market Forces (MF) respectively. Three growth rates and two water demand efficiency levels are considered. It is concluded the rate and type of urban development has major implications for the redesign and operation of existing water infrastructure in terms of total cost, water quality and system resilience, with uniform expansion (PR) resulting in the most cost-effective system upgrade by a considerable margin. Polycentric expansion as a representative urban form for New Sustainability Paradigm is the least cost-effective if it relies on centralised water distribution system to provide service to customers. Edge expansion (MF) has both the cheapest and the most expensive expansion costs depending on location of the expansion. Monocentric urban development (FW) does not result in the most cost-effective system contrary to what has been reported in the literature. Water efficiency measures had relatively little impact on overall performance as it was balanced out with demand increase due to new growth.     

Water Resources Flows Related to Urbanization in China: Challenges and Perspectives for Water Management and Urban Development

China has been experiencing rapid urbanization since the reform and open policy launched in 1978, leading to the growth of urban water demands and aggravating water scarcity especially in the new millennium. Accordingly, water resources previously used for agriculture and environmental systems tend to be transferred to urban systems. Limited by the total quantity and frail environments, the patterns of water resources flows among different sectors and regions change obviously. Water related problems induced by rapid urbanization have become one of the key concerns for scientists and governments. The purpose of this paper is to analyze the new features of water resources flows related to urbanization in China, mainly with regard to bidirectional water resources flows between rural and urban areas, environmental and socio-economic systems, real and virtual water flows between the south and north. This paper also considers the socio-economic and environmental challenges which are resulted from water resources flows in such a case, and provides some countermeasures on how to promote water resources to flow healthily and swimmingly, so as to improve the urban development constrained by scarce water resources.     

城市河段水电开发与城市协调发展的几点经验

攀枝花市是金沙江边一座大型重工业城市,沿江两岸敏感对象众多、水环境问题复杂。金沙江攀枝花河段水电规划,首次提出在我国大江大河的重要城市河段开发水力资源,利用水利工程打造沿江亲水景观带,消除或缓解上游水电站下泄非恒定流对城区的影响,全面提升城市建设质量,探索与尝试传统水利工程与现代城市建设相协调的关系。规划将改善城市水域景观列入河段开发任务;贯彻城市建设和水资源合理利用无缝结合理念;坚持规划环评和水电规划并重的原则,否决了以往提出的在雅砻江口以下河段建坝的方案。可供今后类似规划参考借鉴。     

Integrated Urban Water Resources Management: A Challenge into the 21st Century

The concept of integrated water resources management (IWRM) was introduced in the realm of the International Water Resources Association some 30 years ago. In the context of the urban environment, IWRM requires that management should encompass not only other sectors such as transportation, housing, etc. but also the concurrence of professionals of different disciplines. This paper presents the challenges faced by two metropolitan regions, one in the developed world and one in the developing world. In both cases it is shown that demand management can play a definite role in achieving integrated water management. The complexity of managing the mega-cities of the 21st century will require the creation of a new professional who will be able to coordinate multidisciplinary team work in the water sector.