[Viet Nam] Comp-Flood: Compound flooding in coastal Viet Nam

[越南] Comp-Flood：越南沿海复合洪水

• 批准号: NE/S003150/1
• 负责人: Ivan Haigh
• 金额: $ 47.08万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS003150%2F1
• 关键词: Viet; Nam; Comp; Flood; Compound

Floods are among the most dangerous and costly natural hazards. Since 1980, floods have accounted for more than 200,000 fatalities globally and resulted in at least $1 trillion in economic losses. More than 50% of these deaths and a large proportion of the losses have occurred in densely populated low-lying deltas. Water related disasters are a major concern in deltas because they are located between the sea and major rivers, and hence are subject to flooding from the coastal zone and from rivers. Furthermore, deltas occupy large low-lying areas that are densely populated.In deltas, flooding arises from three main sources: (i) storm tides (storm surges plus tides); but also, from heavy precipitation, either through (ii) increased river discharge (fluvial) and/or (iii) direct surface runoff (pluvial). To date the majority of flood risk assessments in deltas (and other environments) have considered these main causes of flooding separately, because of the lack of information on their inter-dependence, and because of the perceived difficulty in handling the necessary underpinning statistics (known as joint probability analysis methods). However, the adverse consequences of a flood in a delta can be greatly increased when the coastal, fluvial and surface flood sources occur concurrently, or in close succession, resulting in a disproportionately extreme event referred to as 'compound flooding'. Despite their high impact potential, compound events remain poorly understood. This is why the World Climate Research Program has identified compound flood events as an international research priority.This project will bring together UK and Vietnamese expertise to map and characterise present and predict future flood risk, from coastal, fluvial, and surface sources and, uniquely, to assess the risk of compound flooding across the Mekong delta. Exposed to heavy monsoon rains that can cause both fluvial and pluvial flooding, and tropical cyclones that cause coastal flooding, the Mekong is one of the three most vulnerable deltas in the world. Our hypothesis is that previous flood assessments have underestimated the source drivers and hence the likelihood of flooding and associated risk, as compound events have not previously been considered. We propose a new integrated approach, to make a step change in our understanding and prediction of the source mechanisms driving compound flood events in delta regions. We will assess the large-scale drivers of variability in storms and monsoon rainfall that impact Viet Nam and develop novel (for both the past/present and future) meteorological datasets needed to drive the coupled flood models of the Mekong delta and its catchment. This involves use of next-generation climate models, which can simulate both intense monsoon events and tropical cyclones, providing datasets that are sufficiently large for our statistical analysis of flood risk.We will calculate the past/present and future likelihood of coastal and fluvial flooding across the delta, quantifying the occurrence of compound flooding events. For key hot spot areas, we will estimate areas of land inundated, numbers of people affected and how infrastructure and agriculture might be impacted, now and in the future. In particular we will examine low probability, high impact, events and quantify how compounding flood effects from multiple flood sources exacerbate impacts to coastal communities. Working in close partnership with our national, regional and provincial governmental project partners, we will consider management and planning options and provide guidance that will increase preparedness and resilience to future flood events.Our new methods will enable us, for the first time, to fully assess and predict all the source variables associated with compound events in the Mekong delta (at present and in the future) and will result in a major advance in the way compound flooding is understood, quantified and managed.

洪水是最危险和代价最高的自然灾害之一。自 1980 年以来，洪水已导致全球超过 20 万人死亡，并造成至少 1 万亿美元的经济损失。超过 50% 的死亡和很大一部分损失发生在人口稠密的低洼三角洲。与水有关的灾害是三角洲地区的一个主要问题，因为它们位于海洋和主要河流之间，因此容易遭受沿海地区和河流的洪水侵袭。此外，三角洲占据大片低洼地区，人口稠密。在三角洲，洪水主要由三个来源产生：（i）风暴潮（风暴潮加潮汐）；而且，由于强降水，可以通过 (ii) 河流流量增加（河流）和/或 (iii) 直接地表径流（雨水）。迄今为止，三角洲（和其他环境）的大多数洪水风险评估都单独考虑了洪水的这些主要原因，因为缺乏有关它们相互依赖性的信息，并且由于在处理必要的基础统计数据方面存在困难（已知作为联合概率分析方法）。然而，当沿海、河流和地表洪水源同时或连续发生时，三角洲洪水的不利后果可能会大大增加，从而导致称为“复合洪水”的不成比例的极端事件。尽管复合事件具有很高的影响潜力，但人们对其仍然知之甚少。这就是世界气候研究计划将复合洪水事件确定为国际研究优先事项的原因。该项目将汇集英国和越南的专业知识，从沿海、河流和地表来源绘制和描述当前和预测未来的洪水风险，并独特地，评估湄公河三角洲复合洪水的风险。湄公河是世界上三个最脆弱的三角洲之一，季风暴雨可能导致河流和雨洪泛滥，热带气旋可能导致沿海洪水。我们的假设是，之前的洪水评估低估了源头驱动因素，因此低估了洪水发生的可能性和相关风险，因为之前没有考虑到复合事件。我们提出了一种新的综合方法，以在我们对驱动三角洲地区复合洪水事件的源机制的理解和预测方面发生重大变化。我们将评估影响越南的风暴和季风降雨变化的大规模驱动因素，并开发驱动湄公河三角洲及其流域耦合洪水模型所需的新颖（过去/现在和未来）气象数据集。这涉及使用下一代气候模型，该模型可以模拟强烈的季风事件和热带气旋，为我们的洪水风险统计分析提供足够大的数据集。我们将计算过去/现在和未来发生沿海和河流洪水的可能性整个三角洲，量化复合洪水事件的发生。对于重点热点地区，我们将估算现在和未来被淹没的土地面积、受影响的人数以及基础设施和农业可能受到的影响。特别是，我们将研究低概率、高影响的事件，并量化多个洪水源的复合洪水效应如何加剧对沿海社区的影响。我们将与国家、地区和省级政府项目合作伙伴密切合作，考虑管理和规划方案，并提供指导，以加强对未来洪水事件的准备和恢复能力。我们的新方法将使我们首次能够充分评估和预测与湄公河三角洲复合事件相关的所有源变量（当前和未来），并将导致复合洪水的理解、量化和管理方式取得重大进展。

项目成果

Generation of a global synthetic tropical cyclone hazard dataset using STORM.

使用 STORM 生成全球合成热带气旋灾害数据集。

• DOI: http://dx.10.1038/s41597-020-0381-2
• 发表时间: 2020
• 期刊: Scientific data
• 影响因子: 9.8
• 作者: Bloemendaal N

Estimation of global tropical cyclone wind speed probabilities using the STORM dataset.

使用 STORM 数据集估计全球热带气旋风速概率。

• DOI: http://dx.10.1038/s41597-020-00720-x
• 发表时间: 2020
• 期刊: Scientific data
• 影响因子: 9.8
• 作者: Bloemendaal N

Climate-induced storminess forces major increases in future storm surge hazard in the South China Sea region

气候引发的风暴迫使南海地区未来风暴潮灾害大幅增加

• DOI: 10.5194/nhess-2021-397
• 发表时间: 2022-01-17
• 期刊: Natural Hazards and Earth System Sciences
• 影响因子: 4.6
• 作者: Melissa Wood;I. Haigh;Quan Le;H. Nguyen;Hoang Tran;S. Darby;R. Marsh;N. Skliris;J. Hirschi;R. Nicholls;N. Bloemendaal
• 通讯作者: N. Bloemendaal

Drivers of past and predicted changes of rainfall in and around Mainland Southeast Asia

东南亚大陆及其周边地区过去和预测降雨量变化的驱动因素

• DOI: 10.21203/rs.3.rs-194416/v1
• 发表时间: 2021-02-09
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: N. Skliris;R. Marsh;I. Haigh;Melissa Wood;J. Hirschi;S. Darby;N. P. Quynh;N. Hung
• 通讯作者: N. Hung

Compound storm tide and river modelling reveals areas of new flood exposure in the future Mekong River delta

复合风暴潮和河流模型揭示了未来湄公河三角洲新的洪水暴露区域

• 发表时间: 2023
• 期刊: In prep
• 作者: Wood M