Novel tools for quantifying and managing sediment and nutrient loss from agricultural land

这项研究项目是与欧盟关于《水框架指令》的立法有关的，该指令是由于土壤侵蚀和养分流失这一全球性问题而产生的，这些问题通过污染和富营养化威胁到水质。WFD涉及到在2027年前实现所有具有“良好生态状态”的水体的目标，同时确定哪些变量约束或维持这一目标。这些变量通常是特定于特定地点的，与地貌、气候和土地利用有关。在北爱尔兰，超过一半的水体达不到“良好”的生态状态。研究表明，扩散的农业污染源，特别是通过化肥和泥浆施入的磷和硝酸盐，是水体营养丰富和富营养化的主要来源。北爱尔兰存在战后过度使用化肥的问题，恰逢农业集约化，导致土壤中遗留的氮和磷水平过高。最近关于流域管理的研究表明，观测技术要么太具体，要么太粗糙，无法认识到导致水道退化的变量。有必要开展以流域为基础的研究，以了解沉积物营养素损失的规模、频率和程度。该项目旨在开发一种多方法方法来评估和监测农田养分和泥沙的流失。本研究的目的包括：1.进行实地调查，调查沉积物和营养盐的来源和流失，同时采集水样调查水质，并对底栖动物、大型无脊椎动物和植物群落进行分析。利用来自卫星和无人机设备的遥感数据建立数字高程模型，用于模拟模型，以了解泥沙和养分流失的机制。这些数据还将被用来模拟保护方法，以得出一套改善水质的建议。3.应用多光谱图像和实地调查证据，量化、绘制和评估所研究流域的营养物质和泥沙流失区。4.运行流域尺度的土壤侵蚀模型，模拟当前气候、未来气候变化、土地利用和管理情景下的径流和土壤流失变化，以制定适当的缓解战略。北爱尔兰实地考察的重点是黑水、上班恩和科尔布鲁克三个集水区。第一年：调查集水区沉积物和养分的来源和损失。量化路径和移动，评估对土地和水体的破坏程度。利用实地工作(以及遥感，例如无人机和激光雷达数据)和实验室分析技术，确定损失参数和水质状况。第三年：监测实施管理战略后对流域的改善情况，重复原来的实地考察/实验室分析，以确定是否有利于水质，减少沉积物/养分流失。该项目开发的技术和观测技能/方法将适用于许多集水区，在其理论框架中并非纯粹针对北爱尔兰，因此该项目可能会推动新的研究领域。在改善水质和减少泥沙流失方面的项目建议可以应用于研究流域，以推动目前的指令，并指出新的优惠管理技术，以实现2027年的水资源减少目标。

This research project has arisen in relation to the EU's legislation of the Water Framework Directive established due to the global issue of soil erosion and nutrient loss threatening the water quality through pollution and eutrophication. The WFD involves achieving targets of all waterbodies possessing 'good ecological status' by 2027, alongside determining which variables constrain or maintain this. These variables are often site-specific, relating to geomorphology, climate and land-use. In Northern Ireland over half of all waterbodies fail to achieve the 'good' ecological status. Research has indicated that sources of diffuse agricultural pollution, typically from phosphorus and nitrates applied through chemical fertilisers and slurry, are the main source of waterbody nutrient enrichment and eutrophication. Northern Ireland has issues regarding excessive post-war application of fertilisers, coinciding with agricultural intensification, leading to excessive legacy levels of nitrogen and phosphorus present in soils. Recent research on catchment management has shown that observational techniques are either too site-specific or coarse to appreciate the variables contributing to waterway degradation. There is a requirement to develop catchment-based studies to understand the scale, frequency and magnitude of sedimentutrient loss. This project aims to develop a multi-method approach to evaluate and monitor nutrient and sediment loss from agricultural land. The objectives of this study include;1. Undertaking fieldwork to investigate the sources and losses of sediments and nutrients, alongside collecting water samples to investigate water quality with analysis on phytobenthic, macroinvertebrate and plant communities.2. Using remote-sensed data from satellites and drone equipment in the construction of digital elevation models for usage in modelling simulations to understand mechanisms of sediment and nutrient losses. This data will also be used to model conservation methods to derive a set of recommendations to improve water quality. 3. Apply multispectral imagery and fieldwork-based evidence to quantify, map and assess nutrient and sediment loss zones across the studied catchments. 4. Run catchment-scale soil erosion models to simulate runoff and soil loss changes under present-day climate, future climate change, land use and management scenarios in order to design appropriate mitigation strategies. Northern Ireland fieldwork focuses upon three catchment sites of the Blackwater, Upper Bann and Colebrooke.Year One: Investigating the sources and losses of sediment and nutrients in catchments. Quantifying pathways and movement, assessing levels of damage to both land and water bodies. Usage of fieldwork (alongside remote sensing e.g. drones and LiDAR data) and laboratory analysis techniques to establish parameters of losses and water quality status.Year Two: Management strategies instigated at sites to deal with issues of sediment/nutrient loss and water pollution. Field visits to Scotland concerning catchments where management techniques have been introduced and a showing wider context of water pollution and sediment/nutrient loss beyond Northern Ireland.Year Three: Monitoring improvements on catchments following the implementation of management strategies, repetition of original fieldwork/laboratory analysis to establish if benefits to water quality and a reduction in sediment/nutrient losses. The techniques and observational skills/approach developed in this project will be applicable across many catchment areas and is not purely specific to Northern Ireland in its theoretical framework and as such the project may drive new areas of research. The project recommendations in terms of water quality improvement and sediment loss mitigation could be applied to the study catchments to drive current directives and indicate new preferential management techniques to achieve the WFD target by 2027.