The catastrophic impact and unpredictability of the Indian Ocean Monsoon (IOM) over South Asia are evident from devastating floods, mudslides and droughts in one of the most densely populated regions of the globe. However, our understanding as to how the IOM has varied in the past, as well as its impact on local environments, remains limited. This is particularly the case for Sri Lanka, where erosional landscapes have limited the availability of well‐stratified, high‐resolution terrestrial archives. Here, we present novel data from an undisturbed sediment core retrieved from the coastal Bolgoda Lake. This includes the presentation of a revised Late Holocene age model as well as an innovative combination of pollen, source‐specific biomarkers, and compound‐specific stable carbon isotopes of n‐alkanes to reconstruct the shifts in precipitation, salinity and vegetation cover. Our record documents variable climate between 3000 years and the present, with arid conditions c. 2334 and 2067 cal a BP. This extreme dry period was preceded and followed by more wet conditions. The high‐resolution palaeoenvironmental reconstruction fills a major gap in our knowledge on the ramifications of IOM shifts across South Asia and provides insights during a time of major redistribution of dense human settlements across Sri Lanka.

中文翻译：

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使用脂质生物标志物和花粉记录重建斯里兰卡北博尔戈达湖的晚全新世气候和环境历史

印度洋季风 (IOM) 对南亚的灾难性影响和不可预测性从全球人口最稠密地区之一发生的毁灭性洪水、泥石流和干旱中可见一斑。然而，我们对国际移民组织过去的变化及其对当地环境的影响的理解仍然有限。斯里兰卡的情况尤其如此，那里的侵蚀景观限制了分层良好的高分辨率陆地档案的可用性。在这里，我们展示了来自沿海博尔戈达湖的未受干扰沉积物核心的新数据。这包括介绍经过修订的全新世晚期模型以及花粉、特定来源的生物标志物和化合物特定的正构烷烃稳定碳同位素的创新组合，以重建降水的变化，盐度和植被覆盖。我们的记录记录了 3000 年和现在之间的气候变化，干旱条件 c。2334 和 2067 cal a BP。在这个极端干燥的时期之前和之后是更潮湿的条件。高分辨率古环境重建填补了我们对南亚国际移民组织变化影响知识的重大空白，并在斯里兰卡各地密集的人类住区大规模重新分布期间提供了见解。