A STUDY ON EQUILIBRIUM COASTAL PROFILES OF THE CLOSE TIDAL FLAT—A Case Study of Fengxian Tidal Flat

The article analyses the temporal-spatial changes of profiles by EOF(Emipirical Orthogonal Function)analysis and DTM analysis of GIS.These profiles,which are not affected by engineering,are chosen from the coast with successive field monitoring data from 1990 to 1999.Temporal and spatial EOF indicates the obvious stability of coast profile paramclino with steep slopes flat.In spatial scale,high tidal flats and deep-water terraces are in a balance state while upper clino with steep slopes are sensitive and the stability is easy to be destroyes.In temporal scale,the erosion and deposition in this area are kepy in balance in a whole.There are almost no change below -8-9.5m.At the same time,it is the lower limit of tidal affection and the erosion and deposition process from it to high tidal flat keep in balance for many years.So the closre depth is appointed to from -8m to -9.5m(Wusong datum mark).

A study on equilibrium coastal profiles of the close tidal flat

The article analyses the temporal-spatial changes of profiles by EOF (Empirical Orthogonal Function) analy-sis and DTM analysis of GIS. These profiles, which are not affected by engineering, are chosen from the coast with succes-sive field monitoring data from 1990 to 1999. Temporal and spatial EOF indicates the obvious stability of coast profile param-eters in Fengxian tidal flat. In spatial scale, high tidal flats and deep-water terraces are in a balance state while upperclino with steep slopes are sensitive and the stability is easy to be destroyed. In temporal scale, the erosion and deposi-tion in this area are kept in balance in a whole. There are almost no change below -8 - -9.5m. At the same time, it isthe lower limit of tidal affection and the erosion and deposition process from it to high tidal flat keep in balance for manyyears. So the closure depth is appointed to from -8m to -9.5 m (Wusong datum mark).