GCRF_NF332 Ongoing impacts from the surge in sand mining during COVID-19: Enhanced river bank erosion hazard and risk in Vietnam's Mekong delta

东南亚的CV19经济复苏计划严重依赖于建筑业的扩张，这使得整个地区对沙子的需求量很大。沙子通常是从大河中开采的，通常受到管制，因为如果沙子被移走的速度超过河流所取代的速度，它可能会造成不利的社会环境影响，阻碍发展。这些包括河岸侵蚀-威胁到房屋和基础设施-而过度加深的三角洲通道也容易受到盐水入侵。湄公河三角洲已经遇到了这些问题，但这里强调的问题是，CV19的“封锁”-以及潜在的恢复-由于治理能力的限制，导致了不受管制的采砂活动的激增。该提案将在空间上量化这一活动，并预测在即将到来的季风季节（当银行变得饱和）和随后的旱季（银行崩溃通常是在流量衰退期间触发），它将进一步刺激银行侵蚀的程度。还将使用经交通量变化验证的专家知识，沿着对暴露的社会经济资产（例如，道路、学校），以确定灾害、脆弱性和风险的不断变化的空间格局。这项工作是紧迫的，因为人们担心，CV19相关的采矿已经准备好了系统在即将到来的洪水季节严重侵蚀。研究结果将指导补救工作和援助工作，以促进更严格的采砂监管，无论是CV19之后还是未来任何可能刺激非法采矿激增的干扰事件（包括但不限于流行病）。

SE Asia's CV19 economic recovery plan is heavily reliant on an expanded construction industry, creating high demand for sand across the region. Sand is routinely mined from large rivers and is normally subject to regulation because, if it is removed more rapidly than it is replaced by river flows, it can trigger adverse socio-environmental impacts that hinder development. These include bank erosion - threatening homes and infrastructure - while over-deepened delta channels are also prone to saltwater intrusion. The Mekong delta is already experiencing these problems, but the issue highlighted here is that the CV19 'lockdown' - and potentially the recovery - has led to an upsurge in unregulated sand mining due to limitations in governance capacity. This proposal will spatially quantify this activity and predict the extent to which it will further stimulate bank erosion in the forthcoming monsoon season (when banks become saturated) and subsequent dry season (bank collapse is usually triggered during flow recession). Changes in exposed population as a result of internal migration pre- and post lockdown will also be estimated using expert knowledge verified with traffic volume changes, along with an assessment of exposed socio-economic assets (e.g., roads, schools), to establish changing spatial patterns of hazard, vulnerability and risk. This work is urgent because of concerns that CV19 related mining has primed the system for severe erosion during the impending flood season. The results will guide remediation efforts and aid efforts to promote stronger regulation of sand mining, both post CV19 and for any future disrupting events (including, but not limited to, pandemics) that could potentially stimulate an upsurge in illegal mining.