Hydrology-phosphorus interactions under changing climate and land-use: overcoming uncertainties and challenges for prediction to 2050 (Nutcat 2050)

该提案旨在利用英国现有的最新数据和建模方法，在2050年气候和土地利用变化情景下，促进我们对英国水源集水区水文和养分转移之间相互作用的理解和预测。研究集水区将是英国示范试验集水区（DTC），其目标将通过以下方式实现：（1）使用现有的气候模型情景来设定变化的基线结果;（2）以DTC为重点的本地利益相关者启发研讨会，以制定土地利用变化情景，以应对气候情景;（3）模拟当前水文事件和未来流域水文变化，以应对气候/土地利用的变化;（4）对极端水文条件下磷（P）行为的新认识，利用实验和DTCs新获得的高分辨率观测结果为模型开发提供信息;（5）改进预测（6）尝试将信息从源头-集水区扩展到全流域范围;（7）将模型性能与现有的P模型进行比较，并评估这一过程中涉及的不确定性，并进一步迭代利益相关者咨询。我们将重点关注10平方公里的规模，因为这与Defra DTCs（来自Eden、Wensum和Avon DTCs）的9个研究集水区的规模相匹配，这些集水区是我们选择的研究区域;该规模也代表了研究沿着流动-交付-流内影响“转移连续体”过程的理想规模。这些综合研究将产生一个原型的定量评估和预测的营养通量。我们的假设是，增加季节性变化的风暴模式（更极端的事件，长期干旱），结合与土地利用变化的相互作用，将大大改变未来溶解和颗粒磷通量在陆地-水连续体和随后的保留流和下游富营养化的风险。我们将扩展我们最初的“基于系统证据的评估方法（SEBAM）”研究，该研究侧重于农场规模的磷动员（最近由该团队出版），纳入原型建模框架，包括来源，动员，交付和流中处理功能，用于预测英国源头集水区的P通量，并考虑土地利用变化，并使用这个框架（结合团队参与的其他项目的知识）来扩大我们的信息，以确定在全流域范围内预测其他营养行为的潜力。我们将利用新的和独特的高质量，高时间分辨率P监测数据，开始出现从九个Defra DTC子集水区。这项工作的一个独特和令人兴奋的方面将是使用专家启发程序，将模糊不确定性为基础的分析，以制定量身定制的土地利用方案（建立在英国土地利用森林倡议）为每个独特的景观类型的9 DTC重点流域。将这些信息与英国最新的气候情景相结合，我们将包括高分辨率数值天气预报的新发展。然后，我们将使用这些情景来研究2050年气候和土地利用变化对水文，磷动员，交付和流处理的影响，从新的经验学习和实验中获得信息。然后，将使用链接项目和我们的合作伙伴的数据，对更广泛的英国（康威，里布尔，塔兰）的其他集水区的模型输出进行验证。在整个项目过程中，将与利益攸关方一起对成果进行测试。这将提供一个当地拥有的知识为基础的框架，了解和管理未来的营养转移从农村集水系统，和一些令人兴奋的新科学的磷转移。

The proposal aims to advance our understanding and predictions of interactions between hydrology and nutrient transfers in headwater catchments in the UK, under climate and land use change scenarios to 2050, using the very latest data and modeling approaches available for the UK. The study catchments will be the UK Demonstration Test Catchments (DTCs) and the aims will be achieved through: (1) using existing climate model scenarios to set baseline outcomes for change; (2) localized DTC-focused stakeholder elicitation workshops to develop scenarios for land use changes in response to the climate scenarios; (3) simulating current hydrological events and future changes in catchment hydrology in response to changing climate/land use; (4) new understanding of phosphorus (P) behaviour in extreme hydrological conditions, using experiments and newly available high resolution observations from the DTCs to inform model development; (5) improved prediction (with uncertainty) of future P behaviour scenarios arising from the new understanding of hydrology-P interactions; (6) attempting to scale up the information from headwater-catchment to full basin scale, and; (7) compare model performance with existing P models and assess uncertainties involved in this process, with further iterations of stakeholder consultation. We shall focus on the 10 km2 scale because this matches the size of the nine study catchments of the Defra DTCs (from the Eden, Wensum and Avon DTCs), which are our chosen study areas; this scale also represents the ideal size for studying processes along the mobilisation-delivery-in-stream impact 'transfer continuum'. These integrated studies will produce a prototype quantitative assessment and prediction of nutrient fluxes. Our hypothesis is that increased seasonal variability in storm patterns (more extreme events, long drought periods), combined with interactions with land use change, will greatly alter future dissolved and particulate P fluxes across the land-water continuum and subsequent retention in-stream and downstream eutrophication risk. We shall extend our initial 'Systems Evidence Based Assessment Methodology (SEBAM)' study that focused on mobilization of P at the farm scale (recently published by the team), into a prototype modeling framework that includes source, mobilization, delivery and in-stream processing functions for predicting P fluxes from UK headwater catchments, and considers land use change, and use this framework (combined with knowledge from other projects involving the team) to scale up our information to define the potential for predicting other nutrient behaviours at the full basin scale. We will capitalize on the new and unique high quality, high temporal resolution P monitoring data that is starting to emerge from the nine Defra DTC sub-catchments. A unique and exciting aspect of the work will be the use of expert elicitation procedures that incorporate fuzzy uncertainty-based analyses to develop tailored land use scenarios (building on the UK Land Use Foresight Initiative) for each of the unique landscape typologies for the 9 DTC focus catchments. Combining this information with the latest climate scenarios for the UK, we will include new developments in high-resolution numerical weather prediction. We shall then use these scenarios to study the impacts of climate and land use change to 2050 on hydrology, P mobilization, delivery and in-stream processing, informed from new empirical learning and experimentation. Model outputs will then be validated for other catchments in the wider UK (Conwy, Ribble, Tarland) using data from linked projects and our partners. Throughout the project, the outcomes will be tested with stakeholders. This will deliver a locally owned knowledge-based framework for understanding and managing future nutrient transfers from rural catchment systems, and some exciting new science on P transfers.