Response of Ecologically-mediated Shallow Intertidal Shores and their Transitions to extreme hydrodynamic forcing in UK settings (RESIST-UK)

盐沼存在于地球仪周围的低洼、低坡度的海岸边缘。在为社会提供的许多服务中（价值约为每年每公顷1，500英镑），它们的价值在于保护海岸免受波浪和潮汐侵蚀的能力，即使在极端风暴潮事件中。然而，在国家和全球范围内，它们都在下降。在英国，盐沼面积在1945年至2010年间减少了13%（从37，300公顷减少到32，500公顷）。这一损失没有通过沼泽恢复工作得到补偿（到2012年只恢复了1，320公顷）。这些自然海岸保护特征（或其人工恢复或重建的等同物）将如何应对未来海平面变化和风暴强度和/或频率可能变化的综合影响，存在很大的不确定性。如果有足够的沉积物供应，它们也可以垂直“生长”以跟踪海平面上升。因此，随着时间的推移，沼泽面积的减少往往是由于其最向海的边缘向陆地退缩，或者是由于排干沼泽的潮汐通道横向加宽。这些边界经常被削弱，沼泽物质被潮汐和波浪松动和移动。这种后退可能达到每年数米，这是海岸工程师，规划者和管理者非常关注的问题，依赖于这些环境的“风暴缓冲”功能。我们对“切入”盐沼物质（“基质”）所需的力量知之甚少。基质本身是由潮汐随时间推移而沉积的沉积物组成的，还有植物生长产生的有机物质和生活在土壤中的无脊椎动物。因此，它对波浪或潮汐力的抵抗力在沼泽地内部和沼泽地之间是不同的。但是，到目前为止，这种阻力还没有被测量到，使得沿海工程师在预测未来环境情景（例如更大的水深和更强的潮汐流或波浪）的影响时能够考虑到它。在本项目中，我们将详细取样和分析一个更桑迪（沃顿，莫雷坎贝湾）和一个更泥泞（登吉，埃塞克斯）沼泽，以及两个恢复沼泽（两个东海岸管理的重新调整网站）及其相邻的自然等效物的衬底。我们将确定这些基质是由什么组成的，这是如何在这些沼泽之间和每个沼泽内变化的，以及它如何影响沼泽基质对波浪和潮汐力的抵抗力。国家的最先进的技术（无人机（UAV）或“无人机”）和最新的卫星产品将使我们能够产生一个地图的物理沼泽脆弱性的沼泽系统，无论是在其整体和沼泽内，这些类型的力量。沿海规划者，工程师和管理人员将受益于能够更好地预测沼泽损失到未来，并设计适当的预防措施。任何观看我们的三部分纪录短片系列的人都将通过更好地理解我们使用的科学方法而受益。全球社会已经在使用网络工具中内置的现有卫星产品来评估盐沼的海岸保护功能，将受益于能够获得我们将在这些工具中内置的抗波浪/潮汐侵蚀能力预测。

Salt marshes exist around the globe on low-lying, low gradient coastal fringes. Amongst providing many services to society (valued at around £1,500 per hectare per year), they are valued for their ability to protect coasts from the erosive force of waves and tides, even during extreme storm surge events. They are, however, nationally and globally in decline. In the UK, the area of salt marsh reduced by 13% between 1945 and 2010 (from 37,300 to 32,500 ha). This loss has not been compensated for through marsh restoration efforts (only 1,320 ha created by 2012). There is high uncertainty as to how these natural coastal protection features (or their artificially restored or re-created equivalents) will respond to the combined effects of future changes in sea level and possible changes in the magnitude and/or frequency of storms.The grass/shrub covered surfaces of salt marshes appear remarkably resistant to storm impact. Given sufficient sediment supply, they can also 'grow' vertically to track rising sea levels. The loss of marsh area over time is therefore more often due to a landward retreat of their most seaward margin or the lateral widening off the tidal channels that drain them. These boundaries are often undercut, with marsh material loosened and removed by tidal currents and waves. Such retreat may reach several metres per year and is of great concern to coastal engineers, planners, and managers, relying on the 'storm buffering' function of these environments.We know little about the force required to 'cut into' salt marsh material (the 'substrate'). The substrate itself is composed of sediment laid down over time by the tides, alongside organic materials resulting from plant growth and invertebrates living in the soil. Its resistance to wave or tidal forces therefore varies within and between marshes. But this resistance has not, so far, been measured in a way that allows coastal engineers to take it into account when predicting the impact of future environmental scenarios (e.g. greater water depths and stronger tidal currents or waves). In this project, we will sample and analyse in detail the substrate of a more sandy (Warton, Morecambe Bay) and a more muddy (Dengie, Essex) marsh, as well as of two restored marshes (two East coast managed realignment sites) and their adjacent natural equivalents. We will determine what these substrates are composed of, how this varies between and within each of these marshes and how it affects the resistance of the marsh substrate to wave and tidal forces. State-of-the-art technology (unmanned aerial vehicles (UAVs) or 'drones') and the latest satellite products will then allow us to produce a map of the physical marsh vulnerability of marsh systems, both in their entirety and within marsh, to these types of forces. Coastal planners, engineers, and managers will benefit through being able to better predict marsh loss into the future and design suitable preventative measures. Anyone watching our three-part documentary short film series will benefit through a better understanding of the scientific methods we use. The global community already using existing satellite products built into web-based tools for assessing the coastal protection function of salt marshes will benefit by being able to access predictions of the resistance to wave/tide erosion that we will build into those tools.