부산대학교 도서관

As humans continue to inhabit and modify river deltas, the natural processes governing material transport through these landscapes are altered. Two common engineering projects undertaken on deltas are the dredging of channels to enable shipping and the construction of embankments to reduce flooding. While the impact of these topographic modifications has been studied at a local level for specific sites, there is a gap in our generalized understanding of how these landscape modifications impact material transport. To narrow this gap, we conduct exploratory numerical modeling to develop deltaic landscapes with different input sediment compositions, modify their topography to mimic dredging and embankments, simulate different flow conditions, and then model the transport of passive particles. We find that human modification of topography lowers hydrological connectivity by reducing the area visited by fluvial inputs. The amount of time particles spend within the delta is reduced by the construction of polders and is lengthened by dredging. Material buoyancy has a greater impact on nourishment areas and exposure times than flow regime or topographic modification, with positively buoyant particles spending longer and visiting a greater area of the delta than neutral and negatively buoyant material. The results of this study can help guide the design of future engineering projects by providing estimates of their likely impact on transport processes. [ABSTRACT FROM AUTHOR]