关键词: 海岸沙丘, 海岸风沙, 闽江口

Abstract: Along the south coast ofMinjiang estuary, coastal eolian sand makes a wide subtropical coastal dune belt. Its distributing direction is NE-NNE and runs parallel to coastline:Coastal sand dunes develop under the subtropical maritime monsoon climate and normal sea level since late Holocene. Sufficient sand supply, wide beach, strong onshore wind and the space time linkage of dry and stong windy season, available topographic space, the occurrence of periodic cold and dry climate under the trend of drying and cooling, and the strengthening of human activities are the decisive factors to the development of eolian sand dunes. The topographic types of sand dunes are incipient dune, foredune, transverse sand ridge and range, round and elliptic dune, parabolic or upsiloidal dune and sand sheet in their proper order from coastal to inland. Coastal eolian sand is a complicated system composed of natural and human factors. The kernel of its process-response system is that through the transport of sand grains eolian sand dunes exert a self organized process of surface topography and attain a harmonious development between topographic structure and dynamic environment. The age of 14C dating illustrates that the coastal sand dunes began to develop 2470±90a B. P. On their early stage, it presented a slow natural desertization process. From 250a B. P. to now they are in a period of great prosperity and show a natural human desertification process.

Key words: Coastal sand dune, Coastal eolian sand, Minjinag