Abstract: Field investigations with using high-precision RTK GPS technology were conducted at Pingtan Island of Fujian Province before the tenth Typhoon Matmo landed in 2014 and after almost a year. We analyzed morphological change of coastal transverse dune after typhoon Matmo. The results indicated that:(1) The basic morphological impacts of the typhoon Matmo on coastal transverse dune were comprised of reductions in volume and height. Dune volume decreased by 1.30%, and the maximum height of the slope crest was reduced by 1.43 m. However, the magnitude of morphological response was different in different sites over transverse dune.(2) The basic morphological change of coastal transverse dune after typhoon was comprised of increases in volume and height. Not last more than six months, volume and dune height can beyond the pre-typhoon volume and height in profile. The slope crest was monthly averagely increases by 0.39 m. Transverse dune on the windward can side recovery to the same as before the typhoon state, while the heights of leeward slope were increased markedly.(3) Morphological change of coastal transverse dune is related to not only adequate supplies of beach sands, but also strong onshore winds, dune morphology, and vegetation density. Among them, adequate supplies of beach sands and strong onshore winds play a critical role for transverse dune. However, the effect of typhoon on the morphological evolution of coastal transverse dunes is temporary and relatively limited.

Key words: transverse dune, typhoon Matmo, dune morphology, Pingtan Island