Topographic evolution of tidal flats based on remote sensing: an example in Jiangsu coast, Southern Yellow Sea

The topographic evolution of tidal flats is critical for local ecological conservation, coastal zone management, and physical oceanographic studies. However, obtaining this knowledge often challenging due to the lack frequently updated data over large areas. With explosion remotely sensed data, waterline method has become most operational flat topography acquisition. In study, digital elevation models (DEMs) around Tongzhou Bay on Jiangsu coast were constructed using three periods (2013, 2015, 2017) before after construction phase I reclamation project. Furthermore, characteristics analyzed from four aspects: contours, area changes, erosion–deposition distribution, typical cross-sections. results showed that: 1) During 5 years 2013 2017, overall (500 km 2 ) had been in a state deposition, with total siltation thickness 0.19 m. 2) activities affected quickly, but recovery was also rapid. implementation project (in 2015), above −2-m contour rapidly reduced by 20 recovered pre-project level completion 2017). 3) directly distribution erosion siltation. Outside seawall east side Yaosha sand ridge, 0-m expanded outer sea, reaching more than 250 m/year. 4) sandbars generally southward-moving trend. Over past 40 years, ridge shifted southward 2,500 m Lengjiasha 5,000 This study provides remote sensing solution under influence human activities.