Forecasting Risk of Environmental Exacerbation of Dissolved Organic Matter - Building Climate Change Resilience (FREEDOM-BCCR)

随着溶解有机物(DOM)浓度的上升，尤其是提供英国70%饮用水的高地原水供应，水务行业面临着日益加剧的水处理系统风险。雨水和融水渗入土壤，将DOM输送到水库。水务行业必须限制DOM的浓度，以最大限度地减少味道和气味问题，减少藻类生长的可能性，并防止DOM与化学消毒剂之间的反应产生潜在有害水平的消毒双产品。DOM浓度增加的主要原因是土壤有机质溶解度的增加，以应对区域性大气污染物对土壤的减少。然而，旱地水域的DOM水平对土壤温度、降雨量和强度、土壤水的离子强度、水库的停留时间以及冬季风暴期间的海相沉积事件的变化和长期变化也很敏感。随着有机物继续变得更易溶，这些与气候相关的效应的影响正在增加。目前，降低DOM浓度的主要工业方法是应用混凝剂从水中沉淀有机物，但也可能需要额外的过滤来去除对这种化学效应不太敏感的DOM化合物。这两个过程都有很大的碳足迹，据估计，由于安装了新设备，现有基础设施不再能够应对不断上升的DOM浓度，因此该行业已经花费了数亿英镑。因此，迫切需要建立一个气候变化适应能力共同体，该共同体将结合英国研究界和工业界的广泛专业知识，以应对这一挑战。自由-BCCR将开发一种全新的方法来理解、管理和规划应对气候变化的DOM增加的反应。社区将为决策提供支持的基础，并将提供适应性(例如基础设施投资)和缓解(例如土地利用干预)方法，以建立高地供水的复原力。我们将增强原型决策支持工具(DST)的能力，该工具由当前的NERC自由项目开发，并得到苏格兰水公司的支持，通过纳入特定于流域的气候变化预测、预测模型和行业知识来实现。自由DST的这一发展将填补模型功能方面的关键知识空白，包括气候变化对土壤的影响和DOM的水库内处理。我们将为整个处理链中DOM的数量和质量定义操作阈值，并将这些阈值结合在一起，以产生英国规模的DOM对饮用水供应的风险预测。拟议的活动和各自的工作包包括：使用缩减到特定流域的Hydro-Jules生成基于UKCP18的气候变化预测(WP1)；将缩减尺度的气候预测与流域和湖泊/水库模型结合起来，以探索气候变化对优先监测的饮用水水库及其集水区DOM数量、质量和垂直分布的季节性变化的潜在影响(WP2)；在来自苏格兰水的参数化数据集之外，使用从更广泛的英国行业数据了解的后预测，验证自由DST产生的DOM数量和质量的预测(WP3)；推广应用FREE-UK DST，以预测气候变化、土地利用变化和空气污染情景对英国其他区域DOM数量和质量的影响(WP4)；并通过知识交流活动方案(WP5)，促进FREE-UK气候变化适应能力共同体的重点是共同开发、应用和展示DOM(WP5)。

The water industry faces intensifying risks to its water treatment systems through rising dissolved organic matter (DOM) concentrations, especially in upland raw water supplies which provide 70% of the UK's drinking water. Rain and meltwater percolating through soils transports DOM to reservoirs. The water industry has to restrict DOM concentrations to minimise taste and odour problems, reduce the potential for algal growth, and prevent the generation of potentially harmful levels of disinfection bi-products, formed from reactions between DOM and chemical disinfectants. DOM concentrations are increasing primarily as a result of an increase in soil organic matter solubility in response to regional reductions in atmospheric pollutants to soils. However, DOM levels in upland waters are also sensitive to variation, and long-term change, in soil temperatures, amounts and intensity of precipitation, the ionic strength of soil waters, the residence time of reservoirs, and seasalt deposition events during winter storms. The influence of these climate-related effects is increasing as organic matter continues to become more soluble. Currently, the primary industry approach to reduce DOM concentrations is the application of coagulant to precipitate the organic matter from the water, but additional filtration may also be required to remove DOM compounds that are less sensitive to this chemical effect. Both processes have a significant carbon footprint and are estimated to have already cost the industry hundreds of millions of pounds through the installation of new equipment where existing infrastructure was no longer able to deal with rising DOM concentrations. There is a pressing need, therefore, to foster a Climate Change Resilience Community that will combine the extensive expertise of the research and industry communities in the UK in order to address this challenge. FREEDOM-BCCR will develop an entirely new approach to understanding, managing, and planning responses to DOM increases in response to climate change. The community will provide the basis of support for decision making and will deliver adaptive (e.g. infrastructure investment) and mitigative (e.g. land-use interventions) approaches with which to build resilience in the upland water supply. We will augment the capability of a prototype Decision Support tool (DSt), developed by the current NERC FREEDOM Project with support from for Scottish Water, by incorporating catchment-specific climate change projections, predictive models and industry knowledge. This development of the FREEDOM DSt will fill critical knowledge gaps in model functionality including climate change impacts on soil and in-reservoir processing of DOM. We will define operational thresholds for DOM quantity and quality across the treatment chain and combine these to produce forecasts, at a UK scale, of DOM risk to drinking water supply. Proposed activities and respective Work Packages include: generation of UKCP18-based climate change projections using Hydro-JULES downscaled to specific catchments (WP1); Coupling of downscaled climate predictions with catchment and lake/reservoir models to explore the potential impact of climate change in influencing seasonal variation in DOM quantity, quality and vertical distribution in priority intensively monitored drinking water reservoirs and their catchments (WP2); validation of predictions of DOM quantity and quality produced by the FREEDOM DSt, beyond the parameterisation data set from Scottish Water, using hind-casting informed by wider UK industry data (WP3); upscaling application of the FREEDOM-UK DSt to provide predictions of the effects of climate change, land-use change and air pollution scenarios on DOM quantity and quality in other regions of the UK (WP4); and, foster the FREEDOM Climate Change Resilience Community focussing on co-development, application, and show-casing the FREEDOM-UK DSt through a programme of knowledge exchange activities (WP5).