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扩大的建筑行业，这在整个地区创造了对沙子的高需求。沙子通常是从大河中开采的，通常受到监管，因为如果沙子被移除的速度快于河水的替换速度，就会引发不利的社会环境影响，阻碍发展。这些问题包括威胁房屋和基础设施的河岸侵蚀，而过度加深的三角洲河道也容易受到盐水入侵。湄公河三角洲已经经历了这些问题，但这里强调的问题是，由于治理能力的限制，CV19的“封锁”——以及潜在的复苏——导致了无管制采砂的激增。该建议将在空间上量化这一活动，并预测在即将到来的季风季节（当河岸饱和时）和随后的旱季（通常在流量衰退期间引发河岸崩塌），它将进一步刺激河岸侵蚀的程度。还将利用经交通量变化核实的专家知识，以及对暴露的社会经济资产（如道路、学校）的评估，估算封锁前后受影响人口因国内移徙而发生的变化，以确定不断变化的危害、脆弱性和风险空间格局。这项工作是紧急的，因为人们担心CV19相关的采矿已经为即将到来的汛期的严重侵蚀系统做好了准备。研究结果将指导补救工作，并有助于促进加强对采砂的监管，无论是在CV19之后，还是在未来任何可能刺激非法采矿激增的破坏性事件（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.