Analysis on the relationship between suspended sediments and relating

Abstract

Suspended Sediments (SS) in coastal area has high concentration due to terrestrial inputs and sediment resuspension. It also has dynamics variation. For monitoring of SS variation, previous researchers employed the satellite images such as MODIS, SeaWiFS, MERIS and so on. However, it is difficult to monitor dynamic variation of SS in coastal area. In recent years, GOCI, the world's first geostationary satellite ocean color sensor, was launched on June 27, 2010. Although GOCI has low spatial resolution which is 500m by 500m, it provides hourly observation. On other hand, Landsat ETM+ image has high spatial resolution. If we use Landsat ETM+ images, we can supplement the disadvantage of GOCI. In this study, we analyzed the variation of SS concentration in coastal water using GOCI and Landsat ETM+ images in Gyeonggi-bay, Korea. We also analyzed the relationship between SS and environment factors such as water depth, tidal cycle and river discharge. As a result, GOCI could detect the diurnal SS variations in coastal area. And Landsat ETM+ images also observed the seasonal SS variation. SS concentration of GOCI gradually increased after flood time. Also, SS concentration value in summer season shows lower value than winter season. For analysis of relationship between SS concentration and environment factors, we compared SS concentration with the tidal cycle, wind speed and water depth. In shallow depth area, SS concentration had higher value than deep area. In addition, wind speed influences the SS concentration variation in study area. In open sea, SS concentration had high value because of northwest monsoon. Open sea also had no relationship between tide cycle and SS variation. But SS concentrations were decreased up to 1 hour after high tide but increased after that time. In the future, we need to analyse the relationship between SS concentration and tidal flat erosion/deposition based upon SS concentration movement and current velocity combined with numerical models and in situ measurements.