'Can you stop a PDC?' Assessing the impact of natural and engineered barriers on deadly volcanic flows in the built environment.

火山碎屑密度流（PDC）是危险的火山流，有可能超越地形高点，并对附近社区构成风险。相反，其他PDC被观察到被小得多的地形障碍物偏转。数以百万计的人生活在有PDCs风险的地区，因此更好地了解这些危险的火山流至关重要。我的中心研究问题是什么样的地形上的流动特性的致密颗粒PDCs的影响？在本文中，地形可以指自然地形或人造结构，如建筑物或工程障碍物。水槽实验将用于模拟类似于天然PDC的掺气和流化流，以量化不同地形（如障碍物）对密集颗粒PDC流动特性（如流动前沿速度，跳动长度）的影响。在实验水流流过的水槽的底部将设置不同的地形。在这个项目中，我将与我的主管合作：丽贝卡威廉姆斯博士，娜塔莎道伊博士，皮特罗利博士和罗布托马斯博士。预期的产出将包括我的论文。另外，我的目标是在项目期间发表三篇论文（每年一篇）。因为我不是与人或动物一起工作，所以很少有“传统伦理问题”。然而，我的项目仍然存在伦理问题。我的项目直接从一位前硕士生进行的初步工作开始，以测试实验设置，因此我对使用他的数据有道德考虑。我已经从他和他的上司那里获得了必要的许可。在研究造成死亡的火山灾害时，有更广泛的伦理考虑。我必须牢记这一事实，并在进行研究时保持坚忍和尊重的态度。在地球科学中，包括火山学在内，普遍存在着持续的多样性危机。这包括来自所研究火山所在国家的妇女、少数民族和科学家/作者的代表性不足。在我的项目中，我会注意到这一点，并在可能和适当的情况下，包括来自代表性不足的群体的贡献者

Pyroclastic density currents (PDC) are dangerous volcanic flows with the potential to surmount topographic highs and pose a risk to nearby communities. Conversely, other PDCs have been observed as being deflected by much smaller topographic barriers. Millions of people live in areas at risk from PDCs, so it is essential to better understand these dangerous volcanic flows. My central research question is what are the effects of topography on the flow characteristics of dense granular PDCs? In this context, topography can refer to natural topography or man-made structures such as buildings or engineered barriers.Flume experiments will be used to simulate aerated and fluidised flows, analogous to natural PDCs, to quantify the effect of different topographies (e.g. barriers) on the flow characteristics (e.g. flow-front velocity, runout length) of dense granular PDCs. Different topographies will be set up on the bed of the flume over which the experimental currents will flow.In this project I will be collaborating with my supervisors: Dr Rebecca Williams, Dr Natasha Dowey, Dr Pete Rowley, and Dr Rob Thomas. Envisaged outputs will include my thesis. Plus I aim to publish three papers (one each year) during the project.There are few 'traditional ethical concerns' as I am not working with people or animals. However, there are still ethical concerns related to my project. My project directly carries on from preliminary work carried out by a former Masters student to test the experimental setup so I have ethical considerations regarding the use of his data. I have gained the necessary permissions from him and his supervisors. There are ethical considerations more broadly in studying a volcanic hazard which has caused fatalities. I must be mindful of this fact and maintain a stoic and respectful attitude when conducting my research. There is an ongoing diversity crisis in earth sciences more generally, including within volcanology. This includes the under-representation of women, ethnic minorities, and scientists/authors from countries in which the studied volcanoes are located. During my project I will be mindful of this and where possible and appropriate, include contributors from under-represented groups