Spatial planning for adapting to climate change.

During the past decades human interference in regional hydrologic systems has intensified. These systems act as an integrating medium. They link climate, human activities and ecologic processes through groundwater and surface water interactions. For simulating these linkages an integrated regional hydrologic model has been coupled to an ecologic evaluation model. The simulated ecologic effects of climate change on mesotrophic riverine grasslands are clearly positive. Simulation results also indicate a high sensitivity of the peak discharges to the precipitation. For modelling the long-term development of land use and water management an integrated 'bio-economic' model has been constructed. It includes a model for the development of agriculture. Results for the autonomous development in reaction to climate change indicate a strong increase of field drainage by agriculture. This development would substantially reduce the predicted positive effects of climate change on riverine grasslands. The challenge is to guide regional developments in such a manner that opportunities for improving nature are not lost, but that at the same time the peak discharges are kept under control. Flow retardation in the 'fine arteries' of the upstream areas appear to be a viable option for the latter. The bio-economic model can provide help in anticipating on climate change through spatial planning.     

Quantification of increased flood risk due to global climate change for urban river management planning

Global climate change is expected to affect future rainfall patterns. These changes should be taken into account when assessing future flooding risks. This study presents a method for quantifying the increase in flood risk caused by global climate change for use in urban flood risk management. Flood risk in this context is defined as the product of flood damage potential and the probability of its occurrence. The study uses a geographic information system-based flood damage prediction model to calculate the flood damage caused by design storms with different return periods. Estimation of the monetary damages these storms produce and their return periods are precursors to flood risk calculations. The design storms are developed from modified intensity-duration-frequency relationships generated by simulations of global climate change scenarios (e.g. CGCM2A2). The risk assessment method is applied to the Kanda River basin in Tokyo, Japan. The assessment provides insights not only into the flood risk cost increase due to global warming, and the impact that increase may have on flood control infrastructure planning.     

Master planning for stream protection in urban watersheds.

Urbanization results in great changes to the landscape and the water environment simply because stormwater runoff differs in quantity and quality from the pre-urbanization state. Streams, rivers, lakes, estuaries and other receiving water bodies experience the changes to runoff frequencies and volumes and react accordingly. The forces behind the observed changes in the receiving waters are discussed in this paper and suggestions are made on how to plan to deal with them. Urban watershed and waterway master planning can help to mitigate, in large part, the impacts imposed on these waters by land-use changes. Although each watershed is unique, some general principles are suggested to deal with these emergent problems.     

城市防洪规划中的控制要素

城市防洪规划是城市总体规划的组成部分,目前一些防洪规划对城市防洪设施建设缺乏明确的指导意见,难以成为城市防洪工程建设的依据.编制城市防洪规划要确定合适的防洪标准,制定科学的城市防洪方案.防洪方案应结合排洪、调洪、分洪、滞洪和避洪五方面综合作用,以争取最大的安全效益.制定城市防洪方案应该明确提出对排洪河道、防洪水库、分洪区、山地植被和避洪高程共5个方面的若干规划控制要素.     

城市水务投资渠道探讨

城市水务政府投入是必要的，但还应按产业类型明确投资主体；划分事权，形成级投入机制；建立多样化的产权关系、水务建设基金和水务设施耗费补偿机制；大力发展直接融资；扩大引进外资；用好、用足财政贴息政策；理顺水价，只有这样，才能建立起多元化、多层次、多渠道的投入机制，加快城市中水务的发展。     

When climate change is a fact! Adaptive strategies for drinking water production in a changing natural environment.

Climate change increases water system dynamics through temperature changes, changes in precipitation patterns, evaporation, and water quality and water storage in ice packs. Water system dependent economical stakeholders, such as drinking water companies in the Netherlands, have to cope with consequences of climate change, e.g. floods and water shortages in river systems, upcoming of brackish ground water, salt water intrusion, increasing peak demands and microbiological activity due to temperature rise. In the past decades, however, both water systems and drinking water production have become more and more inflexible; water systems have been heavily regulated aiming at maximum security and economic functions and the drinking water supply in the Netherlands has grown into an inflexible, but cheap and reliable, system. At a water catchment scale, flexibility and adaptation are solutions to overcome climate change related consequences. Flexible adaptive strategies for drinking water production comprise new sources for drinking water production, application of storage concepts in the short term, and a redesign of large centralized systems, including flexible treatment plants, in the long term. Transition to flexible concepts will take decades because investment depreciation periods of assets are long. These strategies must be based on thorough knowledge of current assets to seize opportunities for change.     

A decision support framework for sustainable urban water planning and management in new urban areas.

The paper discusses issues of decision support within the context of sustainable development and more specifically sustainable water cycle management to provide a context and a rationale for the decision support approach adopted within an on-going U.K. EPSRC-funded project, WaND. The paper proposes a set-up for a flexible, upgradeable, efficient and modular decision support framework and associated tools. Furthermore, the paper presents early prototypes of three decision support tools developed within the proposed framework including initial results for one of them.     

Synergy of climate change and local pressures on saltwater intrusion in coastal urban areas: effective adaptation for policy planning

ABSTRACT

This article examines the relative impacts of anthropogenic interventions and global climate change on the dynamics of saltwater intrusion in highly urbanized coastal aquifers. For this purpose, simulations of the impacts of sea-level rise and abstraction scenarios for the near future were undertaken for a pilot aquifer using a multi-objective 3D variable-density flow and solute transport model. We find that sea-level rise associated with climate change has less influence on the encroachment of salinity than anthropogenic abstraction, which has a more appreciable impact on saltwater intrusion through greater sensitivity to water consumption and seasonality.     

Adaptation of urban water supply infrastructure to impacts from climate and socioeconomic changes: The case of Hamilton,New Zealand

While the relations between climate variables and sectoral water demand have been well established in the literature, few studies have attempted to quantify changes in urban water usage with climate change. Concentrating on the city of Hamilton, New Zealand, we investigate possible water use and infrastructure needs for a range of climate and population projections. We find that water demand (at the monthly aggregate level) is largely driven by changes in population, and not significantly affected by changes in climate. However, as population increases, the effect of climate variables on per capita consumption will be magnified. Monthly aggregate changes may further mask potenially significant short-term shortages. In several scenarios, water supply shortages in 2030 occur with a 30--40% probability, suggesting needs for long-term capacity expansion or aggressive demand side management, rather than implementation of short-term management of water demand.     

An economic input-output analysis for urban stormwater quality planning

A new approach using input-output techniques is proposed for the analysis of urban stormwater pollution caused by urban land development. The input-output model provides projections of sectoral outputs within an urban region. By defining land as an input to production, these output projections may be translated into projections of commercial and industrial land development. Furthermore, the closed version of the input-output model is used to project residential land development as a function of projected wage income. The pollutant generation in urban stormwater is related to the quantity of each category of land development by a pollutant coefficient matrix. Thus, the model can be used to predict the impact of various economic growth scenarios on pollution loadings in runoff water. This will help planners in assessing the environmental costs of various scenarios, and in preparing for remedial actions. A numerical example is provided to illustrate the applications of the model.     

政策性资金在我国城市水业设施建设中的作用与挑战

在过去的20年中,政策性资金对我国城市水业设施的发展起到了核心的推动作用。“十一五”期间水业建设将持续“十五”期间投资需求旺盛的势头,并且投资对象的公益性更强。在国债逐步淡出,资本市场、商业融资环境尚未完善的背景下,政策性资金的作用变得尤为重要。系统分析了政策性资金在我国水业设施建设过程中所发挥的作用以及“十一五”期间将面临的挑战。最后,就政策性资金应对新挑战时所应发挥的新作用和战略提出建议。     

风险分析方法在城市防洪规划中的应用

基于随机微分方程的堤防设计风险分析方法 ,分析比较了湖南省浏阳市城区防洪规划中所采取的各项工程措施对降低防洪风险的有效性 ,提出了用等可靠度来设计堤防高程 ,可最有效地发挥堤防工程的防洪作用     

The effect of climate change on urban drainage: an evaluation based on regional climate model simulation.

That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps: Firstly, hourly rainfall intensities from 16 point rain gauges are averaged to create a rain gauge equivalent intensity for a 25 x 25 km square corresponding to one grid cell in the climate model. Secondly, the differences between present and future in the climate model is used to project the hourly extreme statistics of the rain gauge surface into the future. Thirdly, the future extremes of the square surface area are downscaled to give point rainfall extremes of the future. The results and conclusions rely heavily on the regional model's suitability in describing extremes at timescales relevant to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change.     

The 2017 African Great Lakes Conference: Conservation and development in a changing climate

In May 2017, the African Great Lakes community convened for a region-wide conference in Entebbe, Uganda. The African Great Lakes Conference (AGLC) focused on 6 regionally-important themes, and 300+ attendees presented over 100 talks and posters. The AGLC culminated in the adoption of a set of Conference Resolutions designed to direct the future of African Great Lakes conservation and management. As an Introduction to this Journal of Great Lakes Research special section on African Great Lakes, we report on the impetus for the African Great Lakes Conference as well as discuss three major advances and investments that were a direct result of conference resolutions adopted at the meeting. First, we present the AGLC Resolutions, a set of management issues and solutions developed at the conference. Second, we discuss the African Great Lakes Conference Fund, a conservation fund that has awarded $500,000 USD to launch four new initiatives. Finally, we describe African Great Lakes Inform, a knowledge management platform designed to promote collaboration in the region. The AGLC in general, and these three major conference outcomes specifically, provide a set of basic building blocks to advance partnerships, research and capacity in the African Great Lakes region.     

Application of dynamic contributing area for modelling the hydrologic response of the Assiniboine River Basin to a changing climate

The Prairie landscape consists of numerous pothole depressions which produce complex fill-and-spill runoff generation processes that result in intermittent hydrologic connectivity and dynamic contributing areas (DCA). We investigated the effect of including DCA in the modified version of the Soil and Water Assessment Tool (SWAT) model and its implication on future streamflow projection for the pothole dominated Assiniboine River Basin (ARB). The fill-and-spill processes that lead to DCA were captured using a physically-based approach, with a volumetric threshold to reduce the computational demand. Despite the challenges in accurately simulating prairie pothole hydrology, both in terms of timing and volume of runoff, the modified approach improved streamflow modelling performance, and reduced model uncertainty. Further, we evaluated the effects of representing DCA on projecting future streamflow by using eight statistically downscaled CMIP5 GCMs, forced with the RCP4.5 and RCP8.5 scenarios. End of century projections indicate increases in annual precipitation and temperature across the ARB, with decreasing summer precipitation relative to the 1976–2005 baseline period. Compared to the standard SWAT setup that does not allow for DCA, the modified model was found to be more responsive to climatic change with relatively larger projected increases in seasonal and annual flows at the majority of evaluated stations. This advance in DCA modelling will facilitate longer-term large basin-scale simulations that are more representative for the Prairie region.     

城市水系发展与保护的规划控制探讨

城市水系是城市空间的重要组成部分,对城市防洪除涝及水生态环境有重要影响。目前,在我国城市化的进程中,城市水系存在着河道被挤占、填埋、硬化、渠化以及污染物入河等突出问题。针对这些问题,应根据城市水系功能和水系发展要求,采取控制城市水面率,扩大水面,划定城市蓝线,选择生态堤岸等措施,还河流以空间、恢复河道自然生态、营造亲水城市。     

A spatial multi-objective optimization model for sustainable urban wastewater system layout planning

Design of a sustainable city has changed the traditional centralized urban wastewater system towards a decentralized or clustering one. Note that there is considerable spatial variability of the factors that affect urban drainage performance including urban catchment characteristics. The potential options are numerous for planning the layout of an urban wastewater system, which are associated with different costs and local environmental impacts. There is thus a need to develop an approach to find the optimal spatial layout for collecting, treating, reusing and discharging the municipal wastewater of a city. In this study, a spatial multi-objective optimization model, called Urban wastewateR system Layout model (URL), was developed. It is solved by a genetic algorithm embedding Monte Carlo sampling and a series of graph algorithms. This model was illustrated by a case study in a newly developing urban area in Beijing, China. Five optimized system layouts were recommended to the local municipality for further detailed design.     

Framing climate change and spatial planning: how risk communication can be improved.

Taking the role of frames into account may significantly add to the tools that have been developed for communication and learning on complex risks and benefits. As part of a larger multidisciplinary study into climate-related forms of sense-making this paper explores which frames are used by the citizens of Western European countries and, in particular, the Netherlands. Three recent multi-national public opinion surveys were analysed to examine beliefs about climate change in the context of beliefs about energy technology and concerns about other environmental issues, such as natural disasters. It appeared that many citizens had only vague ideas about the energy situation and that these do not constitute an unequivocal frame for climate issues. In contrast, the results suggest that the long-lasting rainfall and severe floods in Central Europe have had a significant impact. Climate change was often framed in a way that articulates its associations with rain- and river-based problems. This result is extremely important for risk communication, because especially in the Netherlands with its vulnerable coastal zones climate change may produce many more consequences than rain- and river-based problems only.     

Flooding in the future--predicting climate change, risks and responses in urban areas.

Engineering infrastructure is provided at high cost and is expected to have a useful operational life of decades. However, it is clear that the future is uncertain. Traditional approaches to designing and operating urban storm drainage assets have relied on past performance of natural systems and the ability to extrapolate this performance, together with that of the assets across the usable lifetime. Whether or not climate change is going to significantly alter future weather patterns in Europe, it is clear that it is now incumbent on designers and operators of storm drainage systems to prepare for greater uncertainty in the effectiveness of storm drainage systems. A recent U.K. Government study considered the potential effects of climate and socio-economic change in the U.K. in terms of four future scenarios and what the implications are for the performance of existing storm drainage facilities. In this paper the modelling that was undertaken to try to quantify the changes in risk, together with the effectiveness of responses in managing that risk, are described. It shows that flood risks may increase by a factor of almost 30 times and that traditional engineering measures alone are unlikely to be able to provide protection.     

深圳特区城市中水道系统规划研究

在实现污水再生利用的诸多方式之中,城市中水道是实现污水回用的适宜工程系统,是城市供排水走向水健康循环利用的桥梁。介绍了深圳特区城市中水道系统规划,规划特区中水道供水能力2005年达22万m3/d,2010年为49万m3/d。届时将大幅度缓解水资源不足的压力,显著改善特区水环境。