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张的建筑业，这在整个地区创造了对沙的高需求。沙子通常从大河中开采，通常受到监管，因为如果清除沙子的速度快于被河流水流取代的速度，可能会引发不利的社会环境影响，阻碍发展。其中包括威胁着海岸侵蚀的房屋和基础设施，而过度加深的三角洲河道也容易受到咸水入侵。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--导致了不受监管的采砂热潮。这项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(当河岸饱和时)和随后的旱季(河岸崩塌通常在流量衰退期间引发)，它将进一步刺激河岸侵蚀的程度。还将使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(例如道路、学校)的评估，估计内部移徙封锁前后受影响人口的变化，以确定不断变化的危险、脆弱性和风险的空间模式。这项工作迫在眉睫，因为人们担心与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。这些结果将指导补救工作和援助努力，以促进对采砂的更强有力的监管，无论是在CV19之后，还是针对未来可能刺激非法开采激增的任何破坏性事件(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.