The world's largest rivers transport ~19 billion tonnes of sediment each year, with a significant fraction being sequestered in the large deltas that are home to 14% of the world's population. Most (>70%) of these large deltas are under threat from rising sea levels, ground surface subsidence and declining riverine sediment supply required for delta construction.

However, while measurements and projections of sea level rise and subsidence exist for many deltas, data quantifying historic changes in fluvial sediment supply are sparse, limiting our understanding of how delta building is related to climatic fluctuations. This situation reflects the complexity of controls on river sediment loads, which include the influence of climate and land use change in upland areas, dam construction, and flood driven storage and remobilisation of sediment within the extensive floodplains that characterise the lowland reaches ("sediment transfer zones") of the world's major rivers.

This project will provide the first comprehensive quantification of these controls on riverine sediment fluxes for one of the world's largest rivers (the Mekong), leading to new generic understanding of the relationships between climatic variability, fluvial processes and sediment flux to deltaic zones and the ocean.

An introduction to the STELAR-S2S project. Click play to watch the video

the Mekong River delta as seen from an orbiting space shuttle mission

the Mekong River delta buliding into the South China Sea