IPCC AR6报告解读：气候变化与水安全

保障水安全是应对和缓解气候变化的核心问题,也是实现可持续发展的前提。IPCC第六次评估报告（AR6）第二工作组报告单独设立第四章“水”,分析了气候变化对全球水循环的影响,评估了水循环变化对人类社会和生态系统的影响,指出了当前与未来的水安全风险,分析了与水相关适应措施的收益与成效。报告显示,人类活动导致的气候变化加速了全球水文循环,对水安全产生负面影响,面临水安全风险的人口与地区增多,并增加了由社会经济因素造成的水资源脆弱性。水安全风险随全球升温水平的升高而增加,在水安全脆弱地区表现更为显著。将全球升温限制在1.5℃可有效降低未来的水安全风险,有助于实现水安全、可持续发展和具有气候恢复力的发展三重目标。我国水安全问题突出,急需在“灰-绿”基础设施生态水文效应、三维水资源短缺、水-粮食-能源耦合、地球系统模拟器研发应用等方面重点开展研究工作。     

Deforestation-induced costs on the drinking water supplies of the Mumbai metropolitan,India

The success of incorporating natural capital into resource- and land-use decisions hinges on the ability to quantify the ecosystem services, forecast the returns to the investments, convert these values into effective policy and finance mechanisms, and the presence of well-functioning institutions and infrastructure. However, ecosystem production functions i.e., the relationship between regulatory functions of the ecosystem and the economic activity it protects or supports are often poorly understood. Even with respect to Forest Watershed Services – a service that is widely recognized and even institutionalized through market based mechanisms in some parts of the world – the biophysical relationships between forests and services such as stream flow stabilization, water quality and water quantity are undefined, particularly for the tropics. For this reason, this study through time series data and multivariate analysis characterizes the relationships between Forest Cover (all lands with tree cover of a canopy density of 10% and above when projected vertically on the horizontal ground with minimum areal extent of 1 ha), water quality and cost of water treatment in the Western Ghats of peninsular India. In particular, the recursive relationship between the economic and environmental components is estimated by tracing the effects through the two-stage model. Annual value of impacts (increased ‘treatment cost’, increased ‘water losses due to backwash and desludging’, and changes in ‘water yield’) induced by loss of Forest Cover is estimated as 64.96 Indian rupee/m³ treated water/ha/year ($1.32/m³ treated water/ha/year). At an annual rate of change in the forest cover by −0.0088% (average annual rate of change in the forest cover between the years 1994–2007) the deforestation induced costs translate to 3.73 million Indian rupee/year ($0.075 million/year) according to the 2010–2011 prices for the Panjrapur treatment plant of the Municipal Corporation of Greater Mumbai. Thus, if deforestation is avoided the Municipal Corporation can save significant amount towards recurring costs of water treatment and to some extent mitigate the costs for the development of a new source.     

Risky responsibilities for rural drinking water institutions: The case of unregulated self-supply in Bangladesh

The drinking water sector is off track to reach Sustainable Development Goal (SDG) 6.1 with over a quarter of the world’s population lacking safe and reliable services. Policy approaches are shifting away from provision of access towards managing the multiple risks of water supply and quality. By considering how infrastructure, information, and institutional systems evolved in Bangladesh, this article identifies the unintentional consequences of reallocating management responsibility for rural water services away from government agencies towards individuals and households.Between 2012 and 2017, we estimate up to forty-five unregulated tubewells were installed privately for every publicly funded rural waterpoint. This growth rate more than doubled total national waterpoint infrastructure since 2006. The scale of growth is reflected in the declining ratio of households per tubewell from over fifty-seven in 1982 to less than two in 2017, potentially approaching market saturation. This scale of growth aligns to an observed decrease in the real price of private market shallow tubewells by seventy percent between 1982 and 2017. In 2018, we estimate households invested up to USD253 million in tubewells, nearly sixty-five percent of the total national water and sanitation sector’s household-level finance. In effect, household investments became critical to achieve the Millennium Development Goal (MDG) target of improved infrastructure access, but now pose challenges for meeting targets of safely managed services. The scale of continued private investment provides an opportunity for policymakers to explore blended public finance models to meet emerging consumer preferences, while at the same time introducing regulatory and monitoring systems.     

Quantifying urban water supply security under global change

Urban water supply security is commonly measured in terms of per capita water availability at the city level. However, the actual services that citizens receive are influenced by several components, including (1) a city's access to water, (2) infrastructure for its treatment, storage and distribution, (3) financial capital for building and maintaining infrastructure, and (4) management efficacy for regulating and operating the water system. These four types of "capital" are required for the provision of public water supply services. A fifth capital “community adaptation” is needed when public services are insufficient. Here, we develop and test an integrated framework for the quantification of urban water supply security based on these five capitals. “Security” involves three dimensions: 1) the level of system function (i.e., supply services); 2) risks to these services; and 3) robustness of system functioning. We apply this Capital Portfolio Approach (CPA) to seven urban case studies selected from a wide range of hydro-climatic and socio-economic regions on four continents. Detailed data on urban water infrastructure and services were collected in two cities, and key stakeholder interviews and household surveys were conducted in one city. Additional cities were assessed based on publicly available utility and globally available datasets. We find that in cities with high levels of public services, adaptive capacity remains inactive, while cities with high levels of water insecurity rely on community adaptation for self-provision of services. Inequality in the capacity to adapt leads to variable levels of urban water security and the vulnerability of the urban poor. Results demonstrate the applicability of the presented framework for the assessment of individual urban water systems, as well as for cross-city comparison of any type of cities. We discuss implications for policy and decision-making.     

气候变化对我国若干重大工程的影响

全球气候变化,特别是升温、降水强度增加以及极端天气气候事件频发,会通过影响重大工程的设施本身、重要辅助设备以及重大工程所依托的环境,从而进一步影响工程的安全性、稳定性、可靠性和耐久性,并对重大工程的运行效率和经济效益产生一定影响,气候变化还对重大工程的技术标准和工程措施产生影响。本文以青藏铁路（公路）工程、高速铁路工程、重大水利水电工程为典型工程阐述气候变化对重大工程的影响。青藏铁路（公路）沿线的冻土环境的热平衡极易打破,多年冻土环境一经破坏,难以恢复,气候变化已经使多年冻土环境发生变化,并且未来的多年冻土退化在全球变暖的背景下将变得更加严重。未来中国地区的地表气温、年平均降水量、台风等都将发生变化,极端天气气候事件频发,影响我国高速铁路的气候变化向着不利于高铁工程的趋势发展,将给高铁基础设施的服役寿命以及高铁运输秩序等方面带来影响。气候变化导致的温度变化、降水变化,改变了水资源的时空分布规律,对水工程和水安全在水量分配和调度、水资源利用和水文风险管理等产生影响。     

Climate change adaptation advantage for African road infrastructure

The African continent is facing the potential of a $183.6 billion USD liability to repair and maintain roads damaged from temperature and precipitation changes directly related to predicted climate change through 2100. This cost is strictly to retain the current road inventory. This cost does not include costs associated with impacts to critically needed new roads. In many African countries, limited or non-existent funds for adaptation and mitigation are challenging these countries to identify the threats that are posed by climate change, develop adaptation approaches to the predicted changes, incorporate changes into mid-range and long-term development plans, and secure funding for the proposed and necessary adaptations. Existing studies have attempted to quantify the impact of climate change on infrastructure assets that will be affected by climate change in the coming decades. The current study extends these efforts by specifically addressing the effect of climate change on the African road infrastructure. The study identifies both total costs and opportunity costs of repairing and maintaining infrastructure due to increased stressors from climate change. Proactive and reactive costs are examined for six climate scenarios, with costs ranging, respectively, from an average of $22 million USD to $54 million USD annually per country. A regional analysis shows contrast between impacts in five areas of the continent, with impacts ranging from 22 % opportunity cost to 168 %. These costs have the potential to delay critical infrastructure development on the continent and present a challenge to policy makers balancing short-term needs with long-term planning.     

Water on an urban planet: Urbanization and the reach of urban water infrastructure

Urban growth is increasing the demand for freshwater resources, yet surprisingly the water sources of the world's large cities have never been globally assessed, hampering efforts to assess the distribution and causes of urban water stress. We conducted the first global survey of the large cities’ water sources, and show that previous global hydrologic models that ignored urban water infrastructure significantly overestimated urban water stress. Large cities obtain 78 ± 3% of their water from surface sources, some of which are far away: cumulatively, large cities moved 504 billion liters a day (184 km³ yr⁻¹) a distance of 27,000 ± 3800 km, and the upstream contributing area of urban water sources is 41% of the global land surface. Despite this infrastructure, one in four cities, containing $4.8 ± 0.7 trillion in economic activity, remain water stressed due to geographical and financial limitations. The strategic management of these cities’ water sources is therefore important for the future of the global economy.     

Towards understanding governance for sustainable urban water management

Shifting from traditional, large, centralised infrastructure to alternative, distributed technologies is widely accepted as essential for enabling sustainable water management. Despite technical advances in sustainable urban water management over recent decades, the shift from traditional to more sustainable approaches remains slow. Current research on socio-institutional barriers suggests this poor implementation relates to a limited understanding of the different forms of governance needed to support alternative approaches, rather than the potential ineffectiveness of the technologies and practices. While some governance scholars express preferences for ideal hierarchical, market or network governance approaches, others suggest a hybrid of these approaches may be more appropriate for achieving sustainability. Currently, there is limited commentary about the potential characteristics of sustainable urban water governance. To extend the current scholarship, this paper systematically draws on the tacit knowledge of expert sustainability practitioners to identify potential governance characteristics of sustainable urban water management. In comparison with current urban water scholarship, which is supportive of a network governance approach at a conceptual level, the results strongly suggest that sustainability practitioners see the need for hybrid governance arrangements at a practical and operational level. These hybrid arrangements tended to comprise network and hierarchical approaches with market governance instruments. These insights from practitioners to help identify future research needs, focused on examining interaction among governance approaches at a variety of scales and locations.     

Water security: Debating an emerging paradigm

This paper presents a comprehensive review of the concept of water security, including both academic and policy literatures. The analysis indicates that the use of the term water security has increased significantly in the past decade, across multiple disciplines. The paper presents a comparison of definitions of, and analytical approaches to, water security across the natural and social sciences, which indicates that distinct, and at times incommensurable, methods and scales of analysis are being used. We consider the advantages and disadvantages of narrow versus broad and integrative framings of water security, and explore their utility with reference to integrated water resources management. In conclusion, we argue that an integrative approach to water security brings issues of good governance to the fore, and thus holds promise as a new approach to water management.     

气候变化对城市和农村地区的影响、适应和脆弱性研究的认知

自IPCC第四次评估报告以来,对城市和农村地区气候变化影响、脆弱性、适应和风险管理文献都在增加。第五次评估报告取得了进展。主要包括：气候变化风险、脆弱性与所受的影响在全球范围不同规模、不同经济水平和地理位置的城市中心均在增加。改善基本服务不足的状况以及建设有恢复力的基础设施系统,可以显著降低城市地区的脆弱性和暴露度,特别是对于风险和脆弱性最高的人群来说。气候变化对农村地区的主要影响将体现在对淡水供应、粮食安全和农业收入的影响等方面。发展中国家农村人口更容易遭受多种非气候压力,包括农业投入不足、土地与自然资源政策问题和环境退化。包括增加可再生能源的供给、鼓励生物燃料种植或发展中国家减少砍伐森林和森林退化而造成的碳排放（REDD+）项目等在内的气候政策,将对有些农村地区有重要的间接影响,既有正面的影响（增加就业机会）,也有负面的影响（景观变化和稀有资源冲突增多）。     

气候变化对中国水安全的影响研究

 全球变暖是目前最重要的环境问题之一,水是全球气候变化最直接和最重要的影响领域。全球气候变暖将加速大气环流和水文循环过程,引起水资源量及其空间分布的变化,进而可能导致水资源短缺问题更加突出、水生态环境问题进一步恶化、洪涝灾害威胁更加严重等一系列问题。本文从防洪安全、供水安全、水生态环境安全和水工程安全4个方面分别阐述气候变化对中国水安全的可能影响。     

气候变化对中国水安全的影响研究

全球变暖是目前最重要的环境问题之一,水是全球气候变化最直接和最重要的影响领域。全球气候变暖将加速大气环流和水文循环过程,引起水资源量及其空间分布的变化,进而可能导致水资源短缺问题更加突出、水生态环境问题进一步恶化、洪涝灾害威胁更加严重等一系列问题。本文从防洪安全、供水安全、水生态环境安全和水工程安全4个方面分别阐述气候变化对中国水安全的可能影响。     

近十年来我国气候变暖影响研究的若干进展

近年来，我国政府和科技界十分关注气候王馥棠变暖对我国经济发展可能影响的评估, 开展了许多重大项目和课题的研究。该文仅就气候变暖对我国自然植被、农业、森林、水资源、能源利用和区域海平面上升等领域影响评估研究的若干有意义的初步结果简要归纳和评述如下:取自不同GCM模型的未来气候变化情景下的影响评估模拟表明，我国的特征性自然植被类型将会发生明显的变化。同当前气候（1951~1980年）下的模拟分布相比，到2050年我国几乎所有地方的农业种植制度均将发生较大变化；气候变暖将导致复种指数增加和种植方式多样化，但降水与蒸散之间可能出现的负平衡和土壤水分胁迫的增加以及生育期的可能缩短，最终将导致我国主要作物的产量下降。气候变暖对我国水资源最明显的影响将会发生在黄淮海流域，这个区域的水资源供需短缺将大大提高。同时，气候变暖将改变我国室内取暖和降温的能源需求关系:北方冬季取暖的能源消耗将减少, 而南方夏季降温的能源消耗将会增加。海平面的上升将使我国三个主要沿海低洼脆弱区，即珠江三角洲、长江三角洲和黄河三角洲，面临部分遭受海水淹没的威胁。     

Assisted network governance: An inclusive innovation to mitigate extreme water scarcity

We study a local innovation of natural resource governance in Chile in times of extreme water scarcity. Through the issuance of a scarcity decree, the government obliges local water user associations (WUAs) to reach viable water redistribution agreements in order to avoid being overruled by the state. In the Aconcagua River, the government together with the WUAs created the Executive Committee, where only the WUAs have a vote, but private and public stakeholders participate in the process of negotiating water use agreements. Grounded on thematic coding of the detailed minutes of over 80 committee meetings since its inception, we examine the workings of a new local model of Assisted Network Governance (ANG). Based on content and social network analysis of over 1,000 directed interactions among committee members, we find that ANG, as an element of broader hybrid governance, has not only produced viable agreements for immediate water redistribution, but has also facilitated longer-term system improvements by building mutual understanding, resolving conflicts, and mobilizing external resources to improve infrastructure. We conclude that ANG helps accomplish common objectives in the field of natural resources under conditions of extreme water scarcity.     

气候变化背景下水资源脆弱性研究与展望

论述了气候变化背景下水资源脆弱性概念、内涵及其与适应性管理的联系;综述了水资源脆弱性定量评估方法,包括指标权重法、函数及综合指标法等;介绍了减少水资源脆弱性的适应对策研究。分析表明,联系水资源供需矛盾的水资源脆弱性既有自然变化脆弱性的一面,又有气候变化影响导致水资源供需关系发生变化以及旱涝灾害影响加剧水资源脆弱性的问题。关键是要识别影响水资源脆弱性变化的主要调控变量,通过应对气候变化的适应性对策研究,最大限度地减少水资源脆弱性。未来气候变化背景下水资源脆弱性研究,将在进一步发展脆弱性影响与评估基础上,逐步转到适应性水资源管理与对策的研究。     

Adapting to Climate Impacts on the Supply and Demand for Water

The prospect of climate change adds to future water supply and demand uncertainties and reinforces the need for institutions that facilitate adaptation to changing conditions and promote efficient management of supplies and facilities. High costs and limited opportunities for increasing water supplies with dams, reservoirs, and other infrastructure have curbed the traditional supply-side approach to planning in recent decades. Although new infrastructure may be an appropriate response to climate-induced shifts in hydrologic regimes and water demands, it is difficult to plan for and justify expensive new projects when the magnitude, timing, and even the direction of the changes are unknown. On the other hand, evaluating margins of safety for long-lived structures such as dams and levees should consider the prospect that a greenhouse warming could produce greater hydrologic variability and storm extremes. Integrated river basin management can provide cost-effective increases in reliable supplies in the event of greenhouse warming. With water becoming scarcer and susceptible to variations and changes in the climate, demand management is critical for balancing future demands with supplies. Although regulatory and voluntary measures belong in a comprehensive demand management strategy, greater reliance on markets and prices to allocate supplies and introduce incentives to conserve will help reduce the costs of adapting to climate change. Federal water planning guidelines allow for consideration of plans incorporating changes in existing statutes, regulations, and other institutional arrangements that might be needed to facilitate water transfers and promote efficient management practices in response to changing supply and demand conditions.     

辽宁省辽河流域水污染防治政策与机制的探讨

基于辽宁省辽河流域水环境安全的严峻形势,从产业结构调整与经济布局、环境资源价值、环保投入机制3个方面对造成辽宁省辽河流域水环境问题的主要原因进行了分析,并对现阶段辽宁省辽河流域水污染防治的相关政策与合理机制进行了深入探寻,试图为辽河流域水污染防治的可持续管理提供参考依据。     

Screening robust water infrastructure investments and their trade-offs under global change: A London example

We propose an approach for screening future infrastructure and demand management investments for large water supply systems subject to uncertain future conditions. The approach is demonstrated using the London water supply system. Promising portfolios of interventions (e.g., new supplies, water conservation schemes, etc.) that meet London’s estimated water supply demands in 2035 are shown to face significant trade-offs between financial, engineering and environmental measures of performance. Robust portfolios are identified by contrasting the multi-objective results attained for (1) historically observed baseline conditions versus (2) future global change scenarios. An ensemble of global change scenarios is computed using climate change impacted hydrological flows, plausible water demands, environmentally motivated abstraction reductions, and future energy prices. The proposed multi-scenario trade-off analysis screens for robust investments that provide benefits over a wide range of futures, including those with little change. Our results suggest that 60 percent of intervention portfolios identified as Pareto optimal under historical conditions would fail under future scenarios considered relevant by stakeholders. Those that are able to maintain good performance under historical conditions can no longer be considered to perform optimally under future scenarios. The individual investment options differ significantly in their ability to cope with varying conditions. Visualizing the individual infrastructure and demand management interventions implemented in the Pareto optimal portfolios in multi-dimensional space aids the exploration of how the interventions affect the robustness and performance of the system.     

Climate Variability, Climate Change and Water Resource Management in the Great Lakes

Water managers always have had to cope with climate variability. All water management practices are, to some extent, a response to natural hydrologic variability. Climate change poses a different kind of problem. Adaptation to climate change in water resource management will involve using the kinds of practices and activities currently being used. However, it remains unclear whether or not practices and activities designed with historical climate variability will be able to cope with future variability caused by atmospheric warming. This paper examines the question of adaptation to climate change in the context of Canadian water resources management, emphasizing issues in the context of the Great Lakes, an important binational water resource.     

Fern species richness and abundance are indicators of climate change on high-elevation islands: evidence from an elevational gradient on Tahiti (French Polynesia)

Coastal sector impacts from sea level rise (SLR) are a key component of the projected economic damages of climate change, a major input to decision-making and design of climate policy. Moreover, the ultimate global costs to coastal resources will depend strongly on adaptation, society’s response to cope with the local impacts. This paper presents a new open-source optimization model to assess global coastal impacts from SLR from the perspective of economic efficiency. The Coastal Impact and Adaptation Model (CIAM) determines the optimal strategy for adaptation at the local level, evaluating over 12,000 coastal segments, as described in the DIVA database (Vafeidis et al. 2006), based on their socioeconomic characteristics and the potential impacts of relative sea level rise and uncertain sea level extremes. A deterministic application of CIAM demonstrates the model’s ability to assess local impacts and direct costs, choose the least-cost adaptation, and estimate global net damages for several climate scenarios that account for both global and local components of SLR (Kopp et al. 2014). CIAM finds that there is large potential for coastal adaptation to reduce the expected impacts of SLR compared to the alternative of no adaptation, lowering global net present costs through 2100 by a factor of seven to less than $1.7 trillion, although this does not include initial transition costs to overcome an under-adapted current state. In addition to producing aggregate estimates, CIAM results can also be interpreted at the local level, where retreat (e.g., relocate inland) is often a more cost-effective adaptation strategy than protect (e.g., construct physical defenses).