A quasi-3D numerical modeling of beach scarp generation due to longshore sediment transport mechanism.

在台风、飓风和东北风过后，经常可以看到海滩和沙丘陡坡。在欧盟国家和美国，通常使用跨岸泥沙输运模型计算海滩陡坡和由此导致的海岸线退缩。另一方面，日本多采用n线模型对海岸泥沙输运机制引起的滩陡进行估算。在自然条件下，究竟哪一种作用对滩沙陡坡的形成起主导作用，目前还没有明确的因素。在这里，实地研究是在台风过后进行的，并有证据证明至少海岸过程可以在沙滩上造成海滩陡坡。然后，根据岸线位置和岸岸输沙量的计算，建立了模拟滩崖形成的准三维模型。新概念应用于理想的水深条件。

Beach and dune scarps can be seen often after a typhoon, hurricane and northeaster. In general, beach scarp and resulted shoreline recession are computed using a cross-shore sediment transport model in EU countries and US. On the other hand, beach scarp due to longshore sediment transport mechanics has been often estimated using N-line model in Japan. There is still unknown factor to distinguish which process is dominant to cause beach and dune scarp in natural condition. Here, field studies were conducted after typhoons and evidence to proof that at least longshore process could cause beach scarp in sandy beach. Then, a quasi 3-D model to simulate a beach scarp generation is developed based on longshore sediment transport calculation and resulted shoreline position. The new concept is applied to an idealized bathymetry condition.