sông mã

Characteristics of dynamic geomorphology of coastal-river mouth zones of Ma river, Thanh Hoa province Study of dynamic geomorphological characteristics of coastal-river mouth zones of Song Ma in Thanh Hoa Province has an important meaning for rationally natural resource exploitation and use for local sustainably socioeconomic development. Main factors affecting recent dynamic processes in the coastal-river mouth zones of Song Ma include river flows, nearshore currents and active tectonic movements of the crust; controlling the formation and development of modern topography of the coastal-river mouth zones. Sedimentation process forms banks, bars, mounds, dunes and Holocene-Recent plains at the region of Len and Hoi river mouths. Especially, high accumulation rate at Len river mouth forms larger plains, banks, bars, mounds having seaward aggradational rate about 40-50 m/yr; while at Hoi river mouth, because of low flow carrying lesser source material, weaker deposition, the cumulation rate along the northern and southern coast of Hoi river mouth reaches 5 to 10 m/year. Strong erosional processes are developed at nearshore regions having less dense sediment, small river mouths or no river mouth, or occurence of active faults, such as Lach Truong mouth and in the bank of Hoi river mouth. Maximum erosion in Cửa Lach Truong is about 5 to 6 m/year; while at Cua Hoi the erosion is weaker, only about 3-5 m/year.