The UK Climate Change Risk Assessment 2012: Assessing the Impacts on Water Resources to Inform Policy Makers

The Climate Change Act 2008 requires a series of assessments of the risks of climate for the UK, under both current conditions and over the long term, to 2100. This paper describes the research completed on the impacts of climate change on the UK water sector, involving stakeholder engagement and a mix of literature review, expert elicitation and broad-scale quantitative analysis to develop ten climate change risk metrics. These include measures of the demand for water, impacts on supply, water quality and asset performance using future scenarios based on the UK Climate Projections 2009 and future population projections from the Office for National Statistics. The analysis has resulted in a number of key findings that can help to inform policy in different parts of the UK. Overall the assessment showed that there is likely to be increased pressure on water resources in the UK. These pressures need to be considered in long term plans so that the needs of different users are met without impacting on the environment.     

英国关于未来气候变化的报告

英国关于气候变化对水资源影响的研究报告指出，由于CO2排放量增加，未来80年内温度、降水、土壤温度等条件将发生变化。气候条件的变化使来水条件也将发生很大变化。我国也参与了气候变化的研究报告编制，但还没有形成系统、完整的研究气候变化对水资源影响趋势的成果。了解英国的报告结果，有助于我们重视气候变化对水资源影响的趋势。     

Assessing Impacts of Conservation Measures on Watershed Hydrology Using MIKE SHE Model in the Face of Climate Change

Climate change triggers changes in temperature, precipitation, evapotranspiration, etc. and has a significant impact on water resources in many regions. Considering the increasing scarcity of water as a result of climate change, conservation of water and groundwater recharge have become crucial factors for water resources planning and management. In this paper, an attempt is made to study the detailed hydrological behaviour of a treated watershed using physically based distributed hydrological modelling system MIKE SHE to assess the impact of conservation measures on watershed hydrology considering future climate change. Three hypothetical management scenarios are simulated for the period 2010–2040. RegCM4 regional climate model is used in the study for RCP 4.5 and RCP 8.5 scenarios. Detailed hydrological water balance is extracted for individual years from 1979 to 2009 to compare relevant components. The evaluation for base period shows 10.06% reduction in surface runoff and 11.33% enhancement in groundwater recharge. Further simulation with RCP 4.5 and RCP 8.5 scenarios show notable reduction in surface runoff and increase in groundwater recharge. The structures in the micro-watershed influence the surface runoff and increase infiltration into the soil, resulting in higher groundwater recharge. MIKE SHE simulations for various structures management scenarios establish the role of conservation measures in reducing surface runoff and enhancing groundwater recharge under substantial effect of climate change. The results will assist in decision-making on watershed development plans in quantitative terms, including planning for water conservation measures in the face of climate change.

     

英国气候变化风险评估

英国政府目前正在着手对因气候变化造成的风险进行全面评估,并将制订适应气候变化的计划,以便为应对气候变化提供明确的指导,提高各行业适应气候变化的能力。以水的供需平衡为例,简要阐述了风险评估的过程与结果。结果表明,未来需水量会随温度的上升而增加。因此,有必要采取节约用水和提高用水效率等措施。     

Quantifying Household Water Demand: A Review of Theory and Practice in the UK

Socio-economic change, severe droughts, and environmental concerns focus attention on sustainability of water supplies and the ability of water utilities to meet levels of service. Traditionally, water management has been supply-side dominated and long-term demand forecasting has received relatively little attention. However, it is increasingly recognised that water demand management could be a ‘low regret’ adaptation measure (both financially and environmentally) given large uncertainties about future non-climate and climate pressures. This paper begins with a brief history of household water demand management in the UK. We then review approaches to water demand estimation and forecasting over the short- (daily to season) and long-term (years to decade) and note the paucity of studies on weather and climate. We discuss peak household water use behaviours identified from metering trials, micro-component diary-based studies, and statistical techniques for long-term demand forecasting. We refer to the Anglian Water Services (AWS) ‘Golden 100’ data to illustrate the significant practical and conceptual issues faced when mining household water use data for weather signals, especially when the data are noisy and originally intended for other applications. Further research is needed into the relationships between climate variables and household micro-component water use, especially for peak demands.     

植被覆盖的土质边坡土壤水分平衡模型及应用

土壤水分平衡模型在洪水预测、土壤湿度计算、灌溉设计管理以及全球气候变化影响的仿真分析上十分重要.以英格兰南部Newbury一个高速公路旁的边坡为例,介绍了土壤水分平衡模型的建立及应用.潜在蒸散量根据每日的气象观测资料,用FAO Penman-Monteith公式进行计算.在此基础上,建立了水分平衡模型并进行了校核,计算出的土壤湿度变化与时域反射仪(TDR)探头测量的数据一致.还利用建立的模型,模拟了2080年的气候条件变化对潜在蒸散量和土壤水分含量的影响.结果表明,该地区的日平均潜在蒸散量将增加10.7%,土壤水分消耗量将增加16.8 mm.     

African lake management initiatives: The global connection

There is a global dimension to lake management in Africa and elsewhere that will require a concerted action not only from individual riparian states, but also from regional, continental and global communities. The current global lake threats arise from climate change, regional land degradation and semivolatile contaminants, and share the common feature that the atmosphere is the vector that spreads their impacts over large areas and to many lakes. The Great Lakes of Africa (Malawi, Victoria and Tanganyika) are particularly sensitive to these problems because of their enormous surface areas, slow water flushing rates, and the importance of direct rainfall in their water budgets. Their response times might be slow to yield a detectable change and, unfortunately, their recovery times might also be slow. It is possible for atmospheric effects to act antagonistically to the impacts of catchment change, but antagonistic effects could become synergistic in the future. Improved understanding of the physical dynamics of these lakes, and development of models linking their physical and biogeochemical behaviour to regional, mesoscale climate models, will be necessary to guide lake managers.     

Climate Change in Scotland： Impact on Mini-Hydro

UK Government targets for renewable energy and the new Renewable Obligations suggest a renewed interest in mini-hydropower. However, changes in climate and, in particular precipitation, have been shown to significantly alter the quantity and distribution of river flows. Furthermore, these changes have been shown to impact on the production and, consequently, the economics of large hydropower schemes. The literature highlights that the sensitivity of roduction to changes in climate increases significantly as the amount of storage declines. Given that run-of-river mini-hydropower schemes have little or no storage they may be particularly vulnerable to the changes in river flow quantity and distribution that result from climate change. To assess the threat, a simple software model has been developed that enables an examination of the sensitiy of mini-hydro production and economics to climate change. A possible low-head scheme located in the Scottish Borders is used as a case study. The impact of altered precipitation and temperature on river flows, production and project economics are examined. Consideration is also given to the potential and desirability for making the project more climatically robust.     

气候变化对干旱内陆河流域水资源影响的研究进展

气候变化对水资源的影响是当前全球变化研究的热点和前沿问题之一。气候变化对干旱内陆河流域水资源影响的研究也越来越引起诸多学者的关注与重视。本文回顾了国内外气候变化对水资源影响研究现状与进展,总结了相关的研究方法,并从水文要素、气候变化与人类活动对水资源的定量评估、气候变化对极端水文事件的影响研究和应对气候变化的水资源适应性管理措施4个方面归纳了相关方面的研究成果。同时指出了气候变化对干旱内陆河流域水资源影响研究存在的问题,并展望了未来气候变化对干旱内陆河流域水资源影响研究的发展趋势。     

基于知识图谱的水资源承载力研究的文献计量分析

为分析水资源承载力研究发展状况及趋势,以CNKI数据库收录的2 558篇和WOS数据库收录的512篇水资源承载力研究文献作为数据基础,采用共著分析和共现分析等文献计量可视化分析方法,通过对文献发表的时间分布、学科和期刊分布、高被引文献分布、研究主体分布及研究热点等方面的深入分析,综述了水资源承载力的研究进展。分析结果表明水资源承载力研究是一个正在迅速发展的新兴领域,国内研究热点主要有水资源管理、水资源承载力评价、可持续发展、水环境承载力、水安全、水资源可持续利用,国外研究热点主要有水资源可持续发展、承载力、气候变化、水资源管理、水质、风险评估。     

近30年中国典型区域水体面积变化与归因

在生态文明建设中,水域空间率是一项重要的指标。一般情况下,某个区域中的水体面积越大生态环境越好。而水体面积又受到气候变化与人类活动的双重影响。中国水体面积的变化规律及归因是生态文明建设中一个关键的科学问题。在全国范围内,根据气候条件和经济发展情况,选取了9个研究区域。基于Google Earth Engine云计算平台,使用多个光谱指数组合的方法,对1986-2018年的Landsat影像进行水体提取。采用Mann-Kendall法分析了水体面积动态变化特征,并借助双累积曲线法和分布式水文模型,进一步计算了气候变化和人类活动对水体面积变化的贡献率。结果表明:(1)半干旱半湿润地区受人类活动影响剧烈,水体面积变化显著;(2)湿润地区受气候变化影响,水体面积显著增加;(3)人类对水资源的过度使用、跨流域调水以及水库修建直接决定大部分区域的水体面积变化。该研究能够为生态文明建设提供科技支撑。     

Integrating a Climate Change Assessment Tool into Stakeholder-Driven Water Management Decision-Making Processes in California

There is an emerging consensus in the scientific community that climate change has the potential to significantly alter prevailing hydrologic patterns in California over the course of the 21st Century. This is of profound importance for a system where large investments have been made in hydraulic infrastructure that has been designed and is operated to harmonize dramatic temporal and spatial water supply and water demand variability. Recent work by the authors led to the creation of an integrated hydrology/water management climate change impact assessment framework that can be used to identify tradeoffs between important ecosystem services provided by the California water system associated with future climate change and to evaluate possible adaptation strategies. In spite of the potential impact of climate change, and the availability of a tool for investigating its dimensions, actual water management decision-making processes in California have yet to fully integrate climate change analysis into their planning dialogues. This paper presents an overview of decision-making processes ranked based on the application of a 3S: Sensitivity, Significance, and Stakeholder support, standard, which demonstrates that while climate change is a crucial factor in virtually all water-related decision making in California, it has not typically been considered, at least in any analytical sense. The three highest ranked processes are described in more detail, in particular the role that the new analytical framework could play in arriving at more resilient water management decisions. The authors will engage with stakeholders in these three processes, in hope of moving climate change research from the academic to the policy making arena.     

Applying Optimisation and Uncertainty Analysis to Help Develop an Integrated Water Resources Plan for South East England

The need to promote opportunities for integration between commercially independent water supply providers is becoming important as pressure on water resources increases in many parts of the world. Water stress in south eastern England is projected to increase over the next 25 years, influenced by factors such as: population growth; demographic change; changes in water use; water requirements for environmental protection; and, the potential effects of climate variability and change. Actions to avoid unacceptable deficits in the supply–demand balance are being planned, involving measures to reduce the demand for water and schemes to increase the sharing of water resources within the region. This paper outlines the application of a modelling framework incorporating optimisation modelling and stochastic simulation to help identify options to improve the integration of water resources systems across the region. The regional modelling framework has helped to identify integrated sets of schemes that can provide a cost-effective regional solution for securing the supply–demand balance at an acceptable level of security of supply. These integrated sets of schemes include shared water storage and transfer options that are broader in scope than those considered by individual water companies in drawing up their own water resources plans. Outcomes to-date have included: (a) the identification of cost-effective opportunities for shared resource development and new infrastructure to transfer water from areas of surplus to areas of deficit; (b) interest from the six commercially independent water companies across the region in looking beyond their own water resource zones to develop a better integrated and more sustainable water supply and distribution network across South East England; and (c) valuable insight which is being applied in further regional modelling work to inform the development of the next round of water resources plans due to be submitted by water companies in 2014.     

以不同大气环流模型评估气候变迁对高屏溪流域河川流量

由于气候变迁对于世界各地所造成之影响不一，且不同大气模型模拟所得结果不尽相同，故此类研究存在一定的不确定性。本研究将台湾大学全球变迁中心针对国际政府间气候变迁观察小组(IPCC)公告之大气环流模型(GCM)模拟结果的统计降尺资料，经水文模拟，分析气候变迁对此区域水资源可能造成的冲击及不同模型所得结果之变异。比较不同大气环流模型(包括CGCM2、CCCSR/NIES、ECHAM4、GFDL-R30、HadCM3等模型)所得的情景模拟降雨径流结果，虽然以不同大气环流模型资料模拟后，所得到之流量变化不尽相同，但仍可明显看出在气候变迁影响下，高屏溪流域流量变化趋势大致为，未来丰水期流量上升，而枯水期流量呈现小幅减少趋势。且各模型之变异范围随未来时间愈长其可能变异愈大。枯水期各模型之变异约在-26%~+15%，而丰水期之变异约在-10%~+82%。其中A2情景下枯水期各模型之变异约在-26%~+13%，而丰水期之变异约在-10%~+66%。而B2情景下枯水期各模型之变异约在-18%~+15%，而丰水期之变异约在-3%~+82%。此结果可供相关研究或决策单位参考，以期使气候变迁对水资源之冲击的评估能更佳周详。     

Streamflow Forecast and Reservoir Operation Performance Assessment Under Climate Change

This study attempts to investigate potential impacts of future climate change on streamflow and reservoir operation performance in a Northern American Prairie watershed. System Dynamics is employed as an effective methodology to organize and integrate existing information available on climate change scenarios, watershed hydrologic processes, reservoir operation and water resource assessment system. The second version of the Canadian Centre for Climate Modelling and Analysis Coupled Global Climate Model is selected to generate the climate change scenarios with daily climatic data series for hydrologic modeling. Watershed-based hydrologic and reservoir water dynamics modeling focuses on dynamic processes of both streamflow generation driven by climatic conditions, and the reservoir water dynamics based on reservoir operation rules. The reliability measure describes the effectiveness of present reservoir operation rules to meet various demands which are assumed to remain constant for the next 100 years in order to focus the study on the understanding of the structure and the behaviour of the water supply. Simulation results demonstrate that future climate variation and change may bring more high-peak-streamflow occurrences and more abundant water resources. Current reservoir operation rules can provide a high reliability in drought protection and flood control.     

New climate change scenarios for the Netherlands.

A new set of climate change scenarios for 2050 for the Netherlands was produced recently. The scenarios span a wide range of possible future climate conditions, and include climate variables that are of interest to a broad user community. The scenario values are constructed by combining output from an ensemble of recent General Climate Model (GCM) simulations, Regional Climate Model (RCM) output, meteorological observations and a touch of expert judgment. For temperature, precipitation, potential evaporation and wind four scenarios are constructed, encompassing ranges of both global mean temperature rise in 2050 and the strength of the response of the dominant atmospheric circulation in the area of interest to global warming. For this particular area, wintertime precipitation is seen to increase between 3.5 and 7% per degree global warming, but mean summertime precipitation shows opposite signs depending on the assumed response of the circulation regime. Annual maximum daily mean wind speed shows small changes compared to the observed (natural) variability of this variable. Sea level rise in the North Sea in 2100 ranges between 35 and 85 cm. Preliminary assessment of the impact of the new scenarios on water management and coastal defence policies indicate that particularly dry summer scenarios and increased intensity of extreme daily precipitation deserves additional attention in the near future.     

Incorporating Future Climatic and Socioeconomic Variables in Water Demand Forecasting: A Case Study in Bangkok

With concerns relating to climate change, and its impacts on water supply, there is an increasing emphasis on water utilities to prepare for the anticipated changes so as to ensure sustainability in supply. Forecasting the water demand, which is done through a variety of techniques using diverse explanatory variables, is the primary requirement for any planning and management measure. However, hitherto, the use of future climatic variables in forecasting the water demand has largely been unexplored. To plug this knowledge gap, this study endeavored to forecast the water demand for the Metropolitan Waterworks Authority (MWA) in Thailand using future climatic and socioeconomic data. Accordingly, downscaled climate data from HadCM3 and extrapolated data of socioeconomic variables was used in the model development, using Artificial Neural Networks (ANN). The water demand was forecasted at two scales: annual and monthly, up to the year 2030, with good prediction accuracy (AAREs: 4.76 and 4.82 % respectively). Sensitivity analysis of the explanatory variables revealed that climatic variables have very little effect on the annual water demand. However, the monthly demand is significantly affected by climatic variables, and subsequently climate change, confirming the notion that climate change is a major constraint in ensuring water security for the future. Because the monthly water demand is used in designing storage components of the supply system, and planning inter-basin transfers if required, the results of this study provide the MWA with a useful reference for designing the water supply plan for the years ahead.     

A modeling approach to simulate impact of climate change in lake water quality: Phytoplankton growth rate assessment

Global climate change induced by increased concentrations of greenhouse gases (especially CO₂) is expected to include changes in precipitation, wind speed, incoming solar radiation, and air temperature. These major climate variables directly influence water quality in lakes by altering changes in flow and water temperature balance. High concentration of nutrient enrichment and expected variability of climate can lead to periodic phytoplankton blooms and an alteration of the neutral trophic balance. As a result, dissolved oxygen levels, with low concentrations, can fluctuate widely and algal productivity may reach critical levels. In this work, we will present: 1) recent results of GCMs climate scenarios downscaling project that was held at the University of Derby, UK.; 2) current/future comparative results of a new mathematical lake eutrophication model (LEM) in which output of phytoplankton growth rate and dissolved oxygen will be presented for Suwa lake in Japan as a case study. The model parameters were calibrated for the period of 1973–1983 and validated for the period of 1983–1993. Meteorologic, hydrologic, and lake water quality data of 1990 were selected for the assessment analysis. Statistical relationships between seven daily meteorological time series and three airflow indices were used as a means for downscaling daily outputs of Hadley Centre Climate Model (HadCM2SUL) to the station sub-grid scale.     

1960—2020年南水北调区域极端气象要素变化分析

南水北调工程会引起所涉区域极端气候发生变化,同时极端气候事件对调水工程运行也存在影响。研究以1960—2020年气象观测数据为基础构建极端气象要素指标体系,采用变化范围法(RVA)与集对分析法(SPA)对南水北调影响区极端气象要素的改变程度进行量化计算,揭示了经济发展、气候变化与南水北调工程影响下区域极端气象要素的演变规律。结果表明：在经济发展与气候变化影响下,1960—2020年南水北调影响区极端气象要素指标综合改变度总体为上升趋势,并出现了明显的区域差异性,中线地区极端气候改变度显著大于东线,而两线水源区变化程度低于输水区和受水区;调水前后对比分析表明,工程调水对中线的影响大于东线,且受水区极端气象要素变化程度更为明显;对极端气象要素分析发现,极端蒸发受气候变化与经济发展影响显著,极端气温受调水工程影响变化较大,极端降水受外界扰动变化不明显。     

基于Budyko假设的环境变化对流域径流影响的界定

受气候变化和人类活动的共同影响,流域环境的变化导致流域径流发生了很大的变化,对流域水资源管理提出了新的挑战。区分和界定气候变化与人类活动对流域径流的影响,对减缓和适应环境变化的有关措施和行动具有重要的科学支撑价值,也是流域水资源可持续管理中亟待解决的关键问题之一。目前基于水文模型的划分方法在年以上尺度的分析中存在均化效应和附加误差,且由于参数较多相对比较复杂,存在的不确定性因素较多。本研究基于Budyko假设理论建立一种区分气候变化和人类活动对流域径流影响的界定方法,并选取黄土高原三川河流域进行应用分析,通过与VIC模型分析结果比较研究表明,对于年以上尺度径流变化分析,该研究中建立的方法具有较好的适用性。由于气候变化和人类活动对流域径流的影响缺乏真值,该方法丰富了这一问题的研究理论,增进了对该区域环境变化影响的认识。