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2006ROMS/TOMS Europe Nov 6-8, 2006 Alcala De Henares Spain. Predictability of Seabed Change due to Underwater Sand Mining in Coastal Waters of Korea Chang S. Kim, Hak Soo Lim and Jinah Kim Korea Ocean R&D Institute Coastal Engineering Division 1270 Sa2Dong Ansan 426-744 South Korea.
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2006ROMS/TOMS Europe Nov 6-8, 2006 Alcala De Henares Spain Predictability of Seabed Change due to Underwater Sand Mining in Coastal Waters of Korea Chang S. Kim, Hak Soo Lim and Jinah Kim Korea Ocean R&D Institute Coastal Engineering Division 1270 Sa2Dong Ansan 426-744 South Korea. surfkim@kordi.re.kr
Numerical modeling and field experiment have been conducted to predict the seabed change due to underwater sand mining in coastal waters of Korea. The macro-tidal Kyunggi Bay is approximately 20,000 km2, where underwater sand has been extracted approximately more than 20 million m3 annually. Suspended sediment (SS) transport in the water column and sea bed has been a critically important issue to many concerns. In this study, we present the numerical prediction of sediment transport processes such as SS dispersion and consequent change in sediment types in sea bottom. We use full 3-D model ROMS to implement the sediment dynamics by adopting the extensively observed field data associated with modeling inputs and model validation. Abstract
Numerical Model Grid for Kyunggi Bay Terrain-Following Vertical Grid (20 arrays) Curvilinear Orthogonal Grid
SS Dispersion (Started during Spring Tide) Volume =3,000,000 m3 / 12.5day Ø1:Ø2:Ø3:Ø4:Ø5 = 2:2:2:2:2 Surface Bottom
SS Dispersion (Started During Neap Tide) Volume =3,000,000 m3 / 12.5day Ø1:Ø2:Ø3:Ø4:Ø5 = 2:2:2:2:2 Surface Bottom
Model Validation with Field Observed Data (2,000 m3 3 Barges ) Field Experiment conducted between 14:00 -16:00 on October 12, 2001 in Kyunggi Bay.
Comparison of Model Results and Field Observed Data Vertical Profiles of SS Concentration Observed and Simulated for 14:00-16:00 on October12, 2001 in Kyunggi Bay.
SS Redistribution at Seabed Based on Particle Size (Model Results) Tidal current of 0.5 m/s Extractuin Volume 300,000 m3
Conclusions • In this study, a numerical approach using the fully 3-D model ROMS has been conducted to investigate the sediment dynamics arising from the undersea sand mining operation. Fundamental parameters required for model implementation have been obtained through extensive field experiments done in Kyunggi Bay in Korea. • The estimation of sediment source concentration adapted in this study might be very useful for application to other site-specific area. • The bottom sediment composition is very important to predict the habit change at the seabed. Three-dimensional evolution of sediment transport shows a variety of dependent parameters on environmental impacts, particularly on the geologic change in benthic habitat.