Dept. of Civil Engineering, University of Alicante, Carretera San Vicent del Raspeig s/n, 03690 Alicante, Spain.
Dept. of Civil Engineering, University of Alicante, Carretera San Vicent del Raspeig s/n, 03690 Alicante, Spain.
Sci Total Environ. 2018 Sep 1;634:739-748. doi: 10.1016/j.scitotenv.2018.04.037. Epub 2018 Apr 10.
Storms can alter the beach shape, relocating large volumes of sediments and generating drastic changes in the coastline. In the last 60years, beaches shoreline behaviour has been different even though the energy of the waves was similar. Therefore, it is necessary to understand the factors that affect the sandy coasts for better future management. In this research, two beaches, with different erosion rate, located in the southeast of Spain (separated by only 40km of distance) have been studied. The beaches: i) have similar orientations, ii) are open to waves with similar sand lengths of 9.8km and 6.6km, and iii) have similar median sediment size (D). For its study, shoreline evolution has been analysed from 1956 to 2017. From the results obtained, it can be seen that: i) Between 1992 and 2017, San Juan just lost 3% of its surface, while in the previous period (1956-1990) it was 50%, and ii) Guardamar surface lost in 1992-2017 was 18%, and in the previous period it was 14%. For the analysis of the agents involved in both beaches, cross-shore profiles (volume), marine climate, biocenosis and sedimentology studies were carried out. The results showed that the energy on both beaches was very similar. The biocenosis had not changed and, however, the morphology of Guardamar seabed had increased to 1m deep in some places, which had caused part of the beach berm erosion. Furthermore, important differences were found from the sedimentological study, concluding that the content of calcites and the degree of homogeneity of the particles are the real factors that caused these two beaches to behave differently against erosion.
风暴会改变海滩的形状，使大量沉积物移位，并使海岸线发生剧烈变化。在过去的 60 年中，尽管波能相似，但海滩海岸线的行为却有所不同。因此，有必要了解影响沙质海岸的因素，以实现更好的未来管理。在这项研究中，研究了位于西班牙东南部的两个具有不同侵蚀率的海滩（相距仅 40 公里）。这些海滩：i）具有相似的方位，ii）面向具有相似沙长的波浪，沙长分别为 9.8 公里和 6.6 公里，iii）具有相似的中值泥沙粒径（D）。为了进行研究，从 1956 年到 2017 年分析了海岸线的演化。从获得的结果可以看出：i）1992 年至 2017 年期间，圣胡安仅损失了 3％的表面，而在前一时期（1956-1990 年）则损失了 50％，ii）1992 年至 2017 年期间，瓜尔达马失去的表面为 18％，而在前一时期则为 14％。为了分析两个海滩所涉及的因素，进行了横越剖面（体积）、海洋气候、生物区系和沉积学研究。结果表明，两个海滩的能量非常相似。生物区系没有变化，但是瓜达马雷海底的形态在某些地方增加到 1 米深，这导致了部分海滩堤岸的侵蚀。此外，从沉积学研究中发现了重要的差异，结论是方解石的含量和颗粒的均匀度是导致这两个海滩在抗侵蚀方面表现不同的真正因素。
