Climate change and watershed process interactions: Large-scale Anthropogenic changes to freshwater and nearshore coastal biogeochemical cycles

气候变化和流域过程的相互作用：淡水和近岸沿海生物地球化学循环的大规模人为变化

• 批准号: NE/V014277/1
• 负责人: Taylor Maavara
• 金额: $ 72.46万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV014277%2F1
• 关键词: Climate; change; watershed; process; interactions

Rivers are the great connectors of the freshwater cycle, often considered the continents' "arteries." They provide essential services to humans and ecosystems valued at over $4 trillion USD annually, including drinking water, transportation channels, food security, waste assimilation, and water purification. River systems also harbour more than 10% of known biodiversity, despite accounting for less than 1% of the Earth's surface. Essential nutrient elements such as phosphorus (P), nitrogen (N), and carbon (C) are transported and transformed along river systems from source to sea, forming the basis for freshwater food webs in lakes, rivers, wetlands, reservoirs, and floodplains, and ultimately for marine food webs in estuarine and coastal environments. Rising human populations and resource-intensive lifestyles are driving increased demand for clean water at the same time as freshwater ecosystem degradation is accelerating. Enhanced nutrient loading, urbanization, land use change, and river channelization and damming have massively altered the fluxes of nutrients. The consequences of these changes can be seen worldwide, in the form of toxic algal blooms, fish kills, and in jeopardized drinking water supplies. In England and Wales alone, the annual economic impact of harmful algal blooms has been estimated to be between £75 - 114.3 million. Concurrently, the effects of climate change threaten secure water supplies internationally.While many studies have focused on watershed-level human impacts to river systems like enhanced nutrient loading from agricultural runoff or wastewater treatment plants, very little research has been focused on determining the nature and extent of climate-driven impacts on nutrient cycles. While there is widespread evidence that climate change will massively alter hydrological flows and terrestrial biogeochemical cycles, most studies dedicated to investigate climate change effects on nutrient cycles and subsequent water quality changes are locally based and/or just focus on a single impact such as increased precipitation. The pitfall of studies that focus only on single processes is that feedback cycles that either modulate or exacerbate the magnitude of nutrient loads are neglected. These feedbacks are further compounded by additional climate change effects along the entire freshwater continuum. There is thus a strong need for continental or global-scale models that capture the redistribution of nutrient cycles, particularly those with greenhouse gas and atmospheric components. Large-scale analysis of full nutrient cycles enables the untangling of climate-driven changes to nutrient loads from source to sea, and allows prediction of consequences to ecosystem health along the entire river network and in receiving coastal zones.This research project will couple advances in spatially-explicit computer simulation of river catchments, new global-scale hydrological datasets (MERIT-Hydro and GRADES), and AI techniques, to quantify the effects of interacting multiple stressors of climate change and direct human alterations (land use, damming) on global freshwater nutrient cycles. The resulting high-resolution, global nutrient models offer the prospect of constraining scaling laws that are relevant from the local to global scale. Such a step-change in knowledge could then be utilised by watershed managers to address/reverse problems associated with historic river catchment modifications. Without an understanding of these interacting effects along the entire LOAC, the potential for miscalculating local consequences of costly catchment management interventions to aquatic ecosystem health, and water quality and availability, will remain unacceptably high.

河流是淡水循环的重要连接者，通常被认为是大陆的“动脉”。“它们每年为人类和生态系统提供价值超过4万亿美元的基本服务，包括饮用水，运输渠道，粮食安全，废物同化和水净化。河流系统还拥有超过10%的已知生物多样性，尽管占地球表面的不到1%。必需营养元素如磷（P）、氮（N）和碳（C）沿河流系统从源头沿着流向海洋，形成湖泊、河流、湿地、水库和洪泛平原中的淡水食物网，并最终形成河口和沿海环境中的海洋食物网。人口增长和资源密集型生活方式正在推动对清洁水的需求增加，同时淡水生态系统退化正在加速。养分负荷的增加、城市化、土地利用的变化、河道的渠化和筑坝等都极大地改变了养分的通量。这些变化的后果可以在世界范围内看到，表现为有毒藻类大量繁殖、鱼类死亡和饮用水供应受到危害。仅在英格兰和威尔士，有害藻华每年造成的经济影响估计在7500万至1.143亿英镑之间。同时，气候变化的影响威胁着全球的安全供水。虽然许多研究都集中在流域层面的人类对河流系统的影响，如农业径流或污水处理厂增加的营养负荷，但很少有研究集中在确定气候驱动的营养循环影响的性质和程度上。虽然有广泛的证据表明，气候变化将大规模地改变水文流动和陆地生态地球化学循环，但大多数致力于调查气候变化对养分循环的影响以及随后的水质变化的研究都是以当地为基础的，并且/或者只关注单一的影响，如降水量增加。只关注单一过程的研究的陷阱是忽略了调节或加剧营养负荷大小的反馈循环。沿着整个淡水连续体的其他气候变化影响进一步加剧了这些反馈。因此，迫切需要建立大陆或全球尺度的模型，以反映养分循环的再分配情况，特别是含有温室气体和大气成分的养分循环。大规模的全营养循环分析，使气候驱动的变化，从源头到海洋的营养负荷解开，并允许预测后果的生态系统健康沿着整个河流网络和接收沿海地区。该研究项目将结合在空间上明确的计算机模拟河流流域，新的全球尺度水文数据集的进展（MERIT-Hydro和GRADES）和人工智能技术，以量化气候变化和直接人类改变（土地使用，筑坝）对全球淡水营养循环的相互作用的多重压力的影响。由此产生的高分辨率，全球养分模型提供了前景的约束标度律，是相关的从当地到全球规模。这种知识的逐步变化可以被流域管理者用来解决/扭转与历史河流流域修改相关的问题。如果不了解沿着整个武装冲突法的这些相互作用的影响，就有可能错误估计昂贵的集水区管理干预措施对水生生态系统健康、水质和可用性造成的当地后果，这种可能性仍然很高，令人无法接受。

项目成果

Increased nitrous oxide emissions from global lakes and reservoirs since the pre-industrial era.

• DOI: 10.1038/s41467-024-45061-0
• 发表时间: 2024-01-31
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Li, Ya;Tian, Hanqin;Yao, Yuanzhi;Shi, Hao;Bian, Zihao;Shi, Yu;Wang, Siyuan;Maavara, Taylor;Lauerwald, Ronny;Pan, Shufen
• 通讯作者: Pan, Shufen

Synthesis, homogenisation and regionalisation of inland water greenhouse gas budget estimates for the RECCAP2 initiative

RECCAP2 倡议内陆水域温室气体预算估算的综合、均质化和区域化

• DOI: 10.5194/egusphere-egu23-1333
• 发表时间: 2023
• 作者: Lauerwald R

River ecosystem metabolism and carbon biogeochemistry in a changing world

• DOI: 10.1038/s41586-022-05500-8
• 发表时间: 2023-01
• 期刊: Nature
• 影响因子: 64.8
• 作者: T. Battin;R. Lauerwald;E. Bernhardt;E. Bertuzzo;Lluís Gómez Gener;R. Hall;E. Hotchkiss;T. Maavara

Watershed carbon cycling: Surprises and reassurances from recent modelling efforts

分水岭碳循环：最近建模工作的惊喜和保证

• 发表时间: 2022
• 作者: Maavara T

Inland Water Greenhouse Gas Budgets for RECCAP2: 2. Regionalization and Homogenization of Estimates

• DOI: 10.1029/2022gb007658
• 发表时间: 2023-04
• 期刊: Global Biogeochemical Cycles
• 影响因子: 5.2
• 作者: R. Lauerwald;G. Allen;B. Deemer;Shaoda Liu;T. Maavara;P. Raymond;L. Alcott;D. Bastviken;A. Has