Abstract Foredunes are efficient natural coastal defenses acting as protective barriers during storm events. They also have the capacity to be an ecosystem hosting significant biodiversity. The economic development and/or recreational use of the foredune commonly results in a modification of natural functioning and the concomitant mixing of natural and anthropogenic processes. While the impact of human interventions on the short term evolution of coastal dunes is reasonably well understood, relatively less is known on their imprint at a scale of several decades. The Truc Vert beach-dune system (SW France), which has been exposed to various dune management strategies for more than a century, provides a relevant site to explore the respective contributions of natural and anthropogenic processes on coastal foredune evolution and the current coastal dune landscape. For this purpose, the coastal dune system was investigated using several approaches that combine ground penetrating radar (GPR), topographic data, aerial photographs and historical maps. A 20-m thick GPR sequence provides a stratigraphic record from which we detail ~150-year period of coastal dune change, including the initiation of the foredune. Results show a mixture of radar facies typical of natural aeolian erosion or deposition and radar facies that are the signature of human actions. These anthropogenic works include a large fence emplaced in 1860 to build and fix the foredune, and intense mechanical reshaping of the dune profile by bulldozers in 1972 followed by an intensive planting of vegetation. These various management strategies had a profound influence on coastal dune changes and, in turn, on the current coastal dune landscape. Historic archives documenting coastal dune works were critical to discriminate some of the radar facies, which could be wrongfully interpreted as natural erosion or deposition facies. Therefore, these results demonstrate the importance of coupling GPR and historical documentation wherever possible to determine, in part or fully, the contributions of human interventions and actions in modern dune evolution and morphological development.

中文翻译：

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由人类和自然过程驱动的 150 年的前因启动和进化

摘要 Foredunes 是有效的自然海岸防御，在风暴事件期间充当保护屏障。它们也有能力成为拥有重要生物多样性的生态系统。前因的经济发展和/或娱乐用途通常会导致自然功能的改变以及自然和人为过程的伴随混合。虽然人类干预对沿海沙丘短期演变的影响已经有了很好的理解，但在几十年的规模上，人们对其印记的了解相对较少。一个多世纪以来，Truc Vert 沙滩沙丘系统（法国西南部）一直采用各种沙丘管理策略，提供了一个相关站点来探索自然和人为过程对沿海前缘演化和当前沿海沙丘景观的各自贡献。为此，我们使用多种结合探地雷达 (GPR)、地形数据、航拍照片和历史地图的方法对沿海沙丘系统进行了调查。一个 20 米厚的 GPR 序列提供了一个地层记录，我们从中详细说明了大约 150 年的海岸沙丘变化时期，包括前序的开始。结果显示了典型的自然风蚀或沉积的雷达相与作为人类行为特征的雷达相的混合。这些人为工程包括 1860 年安置的大栅栏，用于建造和修复前哨，1972 年推土机对沙丘轮廓进行了强烈的机械重塑，随后密集种植了植被。这些不同的管理策略对沿海沙丘的变化产生了深远的影响，进而对当前的沿海沙丘景观产生了深远的影响。记录海岸沙丘工程的历史档案对于区分某些雷达相至关重要，这些雷达相可能被错误地解释为自然侵蚀或沉积相。因此，这些结果证明了尽可能将 GPR 和历史文献结合起来的重要性，以部分或全部确定人类干预和行为对现代沙丘演化和形态发展的贡献。在目前的沿海沙丘景观上。记录海岸沙丘工程的历史档案对于区分某些雷达相至关重要，这些雷达相可能被错误地解释为自然侵蚀或沉积相。因此，这些结果证明了尽可能将 GPR 和历史文献结合起来的重要性，以部分或全部确定人类干预和行为对现代沙丘演化和形态发展的贡献。在目前的沿海沙丘景观上。记录海岸沙丘工程的历史档案对于区分某些雷达相至关重要，这些雷达相可能被错误地解释为自然侵蚀或沉积相。因此，这些结果证明了尽可能将 GPR 和历史文献结合起来的重要性，以部分或全部确定人类干预和行为对现代沙丘演化和形态发展的贡献。