Jang, E.-K. and Kang, W., 2023. Improvement of the existing flow discharge-sediment load regression estimation method near the Nakdong River Estuary Bank (NREB). In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 116-120. Charlotte (North Carolina), ISSN 0749-0208.
The Nakdong River Estuary Bank (NREB) was built for preventing salt damage and ensuring sufficient water. Water was smoothly supplied throughout the basin by adjusting the water gate after installing an estuary embankment. Nonetheless, the decrease in flow velocity near the estuary bank resulted in quick sand building upstream of the estuary bank. Analysis of sedimentary flow is essential to solve the problem of river runoff caused by the construction of estuarine embankments and observe topographical changes. The construction of estuaries and opening of sluice gates can affect riverbed slopes and inflow rates, leading to changes in sediment transport patterns. Analyzing and understanding the depositional trends of sediments throughout the Nakdong River watershed and estuary will help determine the balance of hydrological openings. In this study, based on sediment data previously measured in the entire Nakdong River watershed, the sedimentation characteristics around the estuary bank and in the estuary bank-limited section were compared and the differences were quantified. The most commonly used method for estimating the sediment load is a regression formula that uses the relationship between the measured flow and sediment discharges. Also, the limitations of the current flow discharge and sediment load relationship were quantified and attempted to improve for better estimation. Thus, deriving an NREB sediment load estimation formula was possible with improved prediction accuracy compared with the existing method. A data mining technique was used based on the measured data. The sediment estimation model derived using the mining technique is expected to reflect the changes caused by the adjustment of artificial hydraulic coefficients and floodgate openings in the estuary bank area.