Excess riverine sediments are key stressors on the Great Barrier Reef (GBR) ecosystem. Fitzroy Estuary, as the second largest sediment source to the GBR, shows pronounced temporal variability in flow and sediment transport along the river-estuary-coastal-reef continuum. There is lack of high-resolution monitoring and modelling relative to the scales of interannual, seasonal, fortnightly, and semi-diurnal variability on hydrodynamics and sediment transport in the Fitzroy Estuary. This study aims to better understand the seasonal characteristics of sediment being delivered to the GBR and to quantify the sediment fluxes originating from the Fitzroy River into the GBR, especially during major flood events. We took the measurement-to-modelling pathway to continuously monitor the seasonal variability in the estuary over period of 02/2022-03/2023 through three voyages and a high-resolution model was built to predict the sediment budget under different scenarios of physical forcings and morphology setting. We apply these study results to examine the following processes: 1. How river-derived sediments are driven by different estuarine processes from catchment to reef during both dry and wet season? 2. The seasonal variability on sediment budget and the effect of floodplain on sediment trapping. 3. Response of estuary morpho-dynamics to seasonal variations on sediment transport.