Figure 1

(A) Location of the Mekong River delta. Catchments of the Mekong and Red rivers are shaded. The map was derived from ref. ¹⁹ and generated with the software Adobe Illustrator 2020. (B) A map compiling geomorphology of the Mekong River delta⁴⁵ and bathymetry relative to mean sea level and substrate of the coastal area^21,30. A transect (X-X’) is defined by linking six newly obtained drill cores for the cross section in Fig. 2. OSL ages NE and SW of the Bassac River are from existing¹⁶ and newly reported data in this paper, respectively. Shoreline segments are defined following previous spatial analysis¹³ while Seg 1 is further divided here into Segs 1a and 1b by the mouth of the Bassac River. The map was simplified from ref. ⁴⁵ and generated with the software Adobe Illustrator 2020. (C) Temporal variations of average rates of shoreline change from 1973 to 2015 for shoreline segments¹³.