Impacts of Climate Change on Erosion,Sediment Transport and Soil Carbon in the UK and Europe

气候变化对英国和欧洲侵蚀、泥沙输送和土壤碳的影响

• 批准号: NE/E011705/1
• 负责人: Victoria Bell
• 金额: $ 6.17万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FE011705%2F1
• 关键词: Impacts; Climate; Change; Erosion; Sediment

For the government agencies and statutory bodies responsible for management of land and water resources, the past decade has witnessed growing recognition of a series of pressing environmental issues and an awareness that significant uncertainties exist concerning their future trajectories: 1. Erosion by water is the most severe threat to soil in Europe (Kirkby et al., 2004). Furthermore, rates of soil erosion are sensitive to changes in surface runoff, yet spatially-explicit predictions of future erosion rates under changing climatic conditions are not yet available. 2. Redistribution of soil by agricultural tillage is a key influence on the evolving spatial variability of soil properties and productivity (Quine and Zhang, 2002), and consequently exerts a strong control on the emission and sequestration of soil carbon from arable land (Van Oost et al., 2004, 2005). Soils are expected to represent an important control on carbon cycle feedbacks under changing climatic conditions (Cox et al., 2000). However, the role of soil erosion and redistribution in the carbon cycle remains an area of significant controversy, with estimates of the global carbon flux associated with erosion ranging from a 1 Gt/year source to a 1 Gt/year sink (Stallard, 1998; Lal, 2003). 3. Delivery of eroded sediment to river channels causes many environmental problems including diffuse pollution, transport and storage of fine sediment and associated contaminants, degradation of aquatic ecosystems, and changes in flow conveyance capacity and flood frequency due to in-channel and overbank sedimentation (Walling et al., 1999, 2001; Greig et al., 2005). Defra and the Environment Agency currently face the significant challenges posed by implementation of the EC Water Framework Directive (WFD) and the requirement to address the issues highlighted above in order to manage and maintain the ecological status of all surface waters. Furthermore, potential changes in the threats posed by these problems under future climates have yet to be quantified. Tackling these challenges at national and regional scales will necessitate the development of new modelling approaches capable of investigating the feedbacks between climatic, hydrologic, geomorphic and biogeochemical processes, which are poorly understood at present. This project will link CEH and Met. Office expertise in regional climate and hydrological modelling with geomorphological models developed by the universities of Leeds and Exeter to build for CEH a solid, strategic platform from which to address this set of fundamental scientific and environmental questions, which lie at the heart of the EHFI programme, and are central to both CEH and NERC's core missions. This project will build on recent modelling advances to develop new models in the following areas: 1. Hillslope hydrology and soil erosion; 2. Sediment routing within rivers, flood conveyance and floodplain sedimentation; 3. Soil redistribution on hillslopes and soil organic carbon dynamics on slopes and floodplains. All model components will be evaluated and assessed using a wide range of existing data sources. Models will then be implemented within an integrated framework to examine environmental responses to climate change over the next century in the UK and at selected sites in Europe. Key questions that will be addressed using this approach include: 1. What are the effects of projected future changes in climate on soil erosion and sediment delivery into and through river channels? 2. What are the projected effects of climate change and accelerated erosion on river channel morphology, and how might these changes alter future flood risk and sediment storage on floodplains? 3. Can the effects of future changes in climate on the redistribution of soil organic carbon within the landscape be quantified and incorporated as a feedback into future models of terrestrial carbon biogeochemistry? Note: References are in case for support

对于负责土地和水资源管理的政府机构和法定机构来说，过去十年来，人们越来越认识到一系列紧迫的环境问题，并意识到其未来轨迹存在重大不确定性：1.水侵蚀是欧洲土壤面临的最严重威胁（柯克比等人，2004年）。此外，土壤侵蚀率对地表径流的变化很敏感，但在气候变化条件下对未来侵蚀率的空间明确预测尚不可用。2.农业耕作对土壤的再分布对土壤性质和生产力的演变空间变异性具有关键影响（Quine和Zhang，2002年），因此对可耕地的土壤碳排放和固存具有强有力的控制作用（货车Oost等人，2004年、2005年）。预计土壤将在不断变化的气候条件下代表对碳循环反馈的重要控制（考克斯等人，2000年）。然而，土壤侵蚀和再分配在碳循环中的作用仍然是一个有重大争议的领域，与侵蚀有关的全球碳通量估计数从1千兆吨/年的源到1千兆吨/年的汇不等（Stallard，1998年; Lal，2003年）。3.侵蚀沉积物向河道的输送导致许多环境问题，包括扩散污染、细沉积物和相关污染物的运输和储存、水生生态系统的退化以及由于河道内和河岸沉积而导致的水流输送能力和洪水频率的变化（Walling等人，1999，2001; Greig等人，2005年）。Defra和环境局目前面临着欧盟水框架指令（WFD）的实施所带来的重大挑战，以及解决上述问题的要求，以管理和维持所有地表沃茨的生态状况。此外，这些问题在未来气候条件下造成的威胁的潜在变化尚有待量化。要在国家和区域范围内应对这些挑战，就必须开发新的建模方法，能够调查气候、水文、地貌和生物地球化学过程之间的反馈，而目前对这些过程的了解甚少。该项目将连接CEH和Met。利用利兹大学和埃克塞特大学开发的地貌模型进行区域气候和水文建模的办公室专业知识，为CEH建立一个坚实的战略平台，以解决EHFI计划的核心以及CEH和NERC核心任务的基础科学和环境问题。该项目将建立在最新的建模进展，以开发以下领域的新模型：1。坡面水文与土壤侵蚀; 2.河流泥沙运移、洪水输送和漫滩沉积; 3.坡地土壤再分布及坡地与河漫滩土壤有机碳动态。将利用广泛的现有数据来源对模型的所有组成部分进行评价和评估。然后将在一个综合框架内实施模型，以检查英国和欧洲选定地点下个世纪对气候变化的环境响应。使用这种方法将解决的关键问题包括：1。预测的未来气候变化对土壤侵蚀和沉积物进入和通过河道的影响是什么？2.气候变化和加速侵蚀对河道形态的预期影响是什么，这些变化如何改变未来的洪水风险和洪泛区的沉积物储存？3.未来气候变化对景观内土壤有机碳再分布的影响能否被量化，并作为反馈纳入未来的陆地碳地球化学模型？注：参考文件用于支持