Relative sea-level rise is traditionally measured with tide gauges, but we question the reliability of tide-gauge data in low-elevation coastal zones. Benchmark data show that tide gauges typically do not record subsidence in the shallow subsurface and thus underestimate rates of relative sea-level rise. We present an alternative method of measuring relative sea-level rise and conclude that low-elevation coastal zones may be at higher risk of flooding than previously assumed.

We show that in the last 3 kyr the evolution of the Chenier Plain, >200 km west of the Mississippi Delta, was influenced by changes in the position of the main river mouth, local sediment sources and sea-level rise. This information can be used to constrain future generations of numerical models to obtain more robust predictions of the effects of improved sediment management and accelerated rates of relative sea-level rise on the evolution of mud-dominated coastal environments worldwide.

The Ebro Delta in Spain has a distinctive coastline shape, the origin of which has been debated. Here we show with two simple models, one of the Ebro River and one of its delta, that is it possible to reproduce this distinctive shape under constant sediment supply, wave climate, and sea-level conditions. We also find that the majority of the delta grew in the last 2000 years, when a great increase in sediment supply from the Ebro River allowed it to accelerate its growth.

Our work presents a novel method of measuring the capacity of deltaic landforms to trap and retain river-borne sediments, and we demonstrate that sediment retention is closely connected to sedimentary composition. Our results, supported by a unique high-resolution coring dataset in a major crevasse splay, show that finer sediments are a much larger component of the Mississippi Delta than is often acknowledged and that their abundance indicates exceptionally high rates of sediment retention.

This review/position paper addresses problems in creating new interdisciplinary databases for palaeo-climatological sea-level and ice-sheet data and gives an overview on new advances to tackle them. The focus therein is to define and explain strategies and highlight their importance to allow further progress in these fields. It also offers important insights into the general problem of designing competitive databases which are also applicable to other communities within the palaeo-environment.

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.