Pagán J I, Bañón L, López I, Bañón C, Aragonés L
Dept. of Civil Engineering, University of Alicante, Carretera San Vicent del Raspeig s/n, 03690 Alicante, Spain.
AIRLAB, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore.
Sci Total Environ. 2019 Oct 15;687:1034-1045. doi: 10.1016/j.scitotenv.2019.06.186. Epub 2019 Jun 14.
Dune ecosystems play a key role in coastal dynamics, so it is essential to measure their movements with high precision and monitor their changes over time. It is crucial to have a system that allows us to know the natural and anthropic impacts affecting these ecosystems. The aim of this study is to ascertain the historical evolution of the dune system of Guardamar del Segura (Spain) and its relationship with coastal erosion. Likewise, it is also intended to assess the state of the foredune restoration works carried out in 2011. To this end, a comparison of existing cartographic data has been undertaken by using geospatial analysis techniques through Geographic Information Systems (GIS). As a novelty, a low takeoff weight UAV (Unmanned Aerial Vehicle) has been used to produce a high-precision 3D model from two-dimensional images using photogrammetric techniques, such as Structure from Motion (SfM). This technique made it possible to obtain a digital terrain model of high density and precision (30 pt/m and RMSE Z of 0.173 m). The results show a constant erosion of both the beach and the foredune, with an overall loss of 143,561 m of material in the period analyzed (2001-2017). The anthropogenic restoration actions executed within this period have not been effective. In fact, erosion has increased in the period 2016-2017, with a significant reduction in the beach width and sea waves directly affecting the foredune. The main conclusion is that the combined use of UAV and SfM techniques is an excellent procedure to periodically supervise dune ecosystems with high precision and significant time and cost savings.
沙丘生态系统在海岸动力学中起着关键作用，因此高精度测量其移动并监测其随时间的变化至关重要。拥有一个能让我们了解影响这些生态系统的自然和人为影响的系统至关重要。本研究的目的是确定西班牙塞古拉河畔瓜尔达马尔沙丘系统的历史演变及其与海岸侵蚀的关系。同样，本研究还旨在评估2011年开展的前沙丘恢复工程的状况。为此，通过地理信息系统（GIS）使用地理空间分析技术对现有的地图数据进行了比较。作为一项创新，使用了一架低起飞重量的无人机（无人驾驶飞行器），通过摄影测量技术（如运动结构法（SfM））从二维图像生成高精度三维模型。该技术使得能够获得高密度和高精度的数字地形模型（30点/米，Z方向均方根误差为0.173米）。结果表明，海滩和前沙丘均持续受到侵蚀，在分析期（2001 - 2017年）内总共损失了143,561立方米的物质。在此期间实施的人为恢复行动并未奏效。事实上，在2016 - 2017年期间侵蚀加剧，海滩宽度显著减小，海浪直接影响到前沙丘。主要结论是，无人机和SfM技术的联合使用是一种极好的方法，可定期对沙丘生态系统进行高精度监测，并显著节省时间和成本。
