Local/Spatial Variation of Settling Velocities of Cohesive Sediments from Han Estuary

J. Ocean Eng. Technol. 2008;22(1):37-45.

Seo Young-Deok,Jin Jae-Youll,Hwang Kyu-Nam

Dept. of Civil Eng Chonbuk National Univ,Coastal Engineering Research Department KORDI,Dept. of Civil Eng & RICT Chonbuk National Univ

한강 하구역 점착성 퇴적물 침강속도의 지엽적/공간적 변화

서영덕,진재율,황규남

전북대학교 토목공학과,한국해양연구원 연안개발연구본부 해양에너지.환경개선연구사업단,전북대학교 토목공학과.공업기술연구센터

Keywords: Cohesive sediments, Settling velocity, Physico-chemical properties, Han estuary

핵심용어: 점착성 퇴적물, 침강속도, 물리.화학적 특성, 한강하구

Abstract

The purpose of this study is to quantify the settling velocities of cohesive sediments from Han estuary and to evaluate their local variation within Han estuary. This study also includes an estimation of their spatial variation, for which the settling velocities of cohesive sediments from Han estuary arecompared with those for sediments from other regions. At the same time, physical-chemical properties, such as grain size distribution, the percentage of organic contents, mineralogical composition etc are measured in this study in order to examine their correlation with settling velocities and their effect on settling velocities.
Results
from settling tests shaw that the settling velocities of Han estuary mud varies in the range of two orders of magnitude(from 0.01 to 1.5 mm/sec) over the corresponding concentration range of 0.1 to 80 g/L, and a feature of the settling velocity profile is quite different in quantity as compared to those of previous studies for muds from other regions. Particularly in the flocculated settling region, the settling velocity for Han estuary muds is shown to be larger than that of Saemankeum and Keum estuary sediments, while in the hindered settling region all three sediments are shown to have a similar settling velocity. However, local variability of the settling velocities within Han estuary is shown to be insignificant.