The Mekong Delta is one of the largest and most intensively used estuaries in the world. It experiences annual widespread flooding, which provide the basis of livelihood for about 17 million people in the Mekong Delta, but they also pose a considerable hazard when extreme events exceed protection levels. Especially since the Delta in Vietnam is intensively used for agriculture, the pristine natural floodplains have been altered to channel networks, dike rings, paddy fields and aquaculture ponds. Sediment dynamics play an important role in carrying contaminants, bacteria, nutrients, heavy metals, phytoplankton, pesticides, etc. They are the primary source for the productivity of biota in floodplains as well as a sustainable agroecosystem within the Delta. However, little is known about the dynamics of these suspended sediments, including multi-processes erosion, deposition, and suspension in the complex channel network of the Delta. In particular, quantitative analyses are lacking, mainly because of lacking data about the inundation processes in the floodplains. In 2008, therefore, a comprehensive in-situ monitoring scheme to monitor floodplain inundation as well as the dynamics of suspended sediment was established in a study area of the North-Eastern part of the Delta, the Plain of Reeds. The in-situ monitoring system is equipped with twenty-one water level probes and seven water quality monitoring stations. They all have a robust design, autonomous power supply, and the ability to gather reliable data over a long period of time with a high temporal resolution. The water quality parameters include suspended sediment concentration, pH, EC (electrical conductivity) and water temperature. Sediment traps were installed additionally and used in combination with recorded suspended sediment loads to investigate deposition and erosion in the floodplains. This in-situ data collection was complemented by high-resolution inundation maps derived from the TerraSAR-X satellite. Hence, the floodplain hydrology of the Delta could be described quantitatively for the first time. In detail, the present study investigates:(1) spatial and temporal floodplain inundation processes, (2) anthropogenic influence on floodplain hydrology, (3) the tidal influence on flow regime, (4) suspended sediment dynamics, and (5) the erosion and deposition processes during flood season. These processes were analysed quantitatively, providing insights into basic control parameters, dynamics of the processes and the quantity and timing of human interference. The practical contribution of this study is to fill the knowledge gaps in water resources management in order to foster a sustainable future development of the Delta. The scientific contributions are the new ideas in the in-situ monitoring system for floodplain inundation study. In particular, it provided insights into the sedimentation process and enabled an estimation of the key parameters for deposition and erosion as a basis for future model based quantitative estimations of floodplain sedimentation.