What can we learn from recent development of the Atchafalaya River Delta, USA and the Yellow River Delta, China?

Over the past century many river deltas throughout the world have been altered by anthropogenic disturbances, both to the deltas as well as to their drainage basins. Alterations such as dam construction, channel modification, and land cover changes in the drainage basins have led to changes in riverine sediment transport, deposition, distribution, and deltaic subsidence. Two of the most highly engineered rivers in the world are the Mississippi-Atchafalaya River system in the United States and the Yellow River (Huanghe) in China. Both have experienced tremendous hydrologic and land-use changes in the past. The anthropogenic changes have caused the Mississippi River Delta Plain to undergo land loss endangering coastal communities and impacting major economies. Even with land loss, the main distributary of the Mississippi, the Atchafalaya River, has developed a prograding delta feature at the man-made Wax Lake Outlet and main stem south of Morgan City, Louisiana. The Yellow River has also experienced many alterations with dams completed over the past 50 years, and agriculture expansion within the drainage basin. This has led to interrupted river discharge and large decline in sediment delivery to the river mouth. In the recent years, wetland loss has been observed in the Yellow River Delta. An understanding of how these two deltas respond to land and river alterations is integral to continued sustainability of environmental, commercial, and industrial capabilities. This study compares over 20 years (1989-2010) of delta development (growth/erosion) at approximately 5-year intervals in these two largely modified river systems using remotely sensed images, river discharge, and suspended sediment yield data to better understand the long-term effect of river alterations on deltaic development.