Accurate elevation data is essential for flood risk assessment. We assess land elevation to local mean sea level of the Ayeyarwady Delta with a new, local DEM based on geodetic data and evaluate the performance of 10 global DEMs in an SLR impact assessment. Our study reveals major differences in performance between global DEMs and consequentially introduced uncertainty in SLR impact assessments, indicating potential similar uncertainties for other data-poor coastal lowlands around the world.

We demonstrate that the world's largest beach-ridge plain in southern Mexico was formed under an ample long-term fluvial sediment supply. The beach-ridge elevation is strongly influenced by aeolian accretion during the time when the ridge is located next to the beach. The beach-ridge elevation is negatively correlated with the progradation rate, which we relate to the variability in sediment supply to the coastal zone, reflecting decadal-scale precipitation changes within the river catchment.

Land subsidence rates of ~1-4 cm yr-1 are measured in the low-lying Vietnamese Mekong Delta. These relatively high subsidence rates are attributed to groundwater extraction, which has increased drastically over the past decades. There is an urgent need to go from measurements to predictions to test future groundwater management scenarios and reduce subsidence. In this study, we present an approach to build a 3D geo-hydrological model to determine the subsidence potential of the Mekong Delta.