태풍 "매미" 내습시 낙동강 하구역 부유쓰레기 거동 특성

Abstract

Nakdong river estuary located at the south-eastern coast of the Korea shows very unstable topographical changes due to the various uses of the wet-land area, and/or changes of interactions between environments: such as sediments, waves and currents. A lot of studies concerned about behavior of marine debris have been carried hardly out on the initial condition and distribution as inflow in Nakdong river estuary. Especially, when a typhoon propagates to Korea peninsula many floating debris come into the estuary and pollutes coastline around Nakding river estuary. The aim of the study is to clarify the behavior of floating debris released from inland and their spatial distribution in Nakdong Estuary. this study therefore carried out mainly by checking distribution status around Nakdong river estuary and monitoring on the settled floating debris in the Jinudo. To examine the behavior of floating debris over the study area, we applied a 2D numerical model coupled with tidal current circulation and particle tracking. Main results obtained in this study are summarized as follows: 1) From the campaign of floating debris which settled coastline in Nakdong river estuary, We found that 80 % of floating debris in Nakdong river estuary is the wood, and estimated about 240 ton of floating debris settle at coastline using monitoring in Jinudo. 2) When the typhoon "Maemi" pass over Korea peninsula, the discharge in Nakdong estuary dam was 17,803 ton/sec. we applied the quantity at the model boundary of Nakdong estuary dam for the 15 days simulation. The model result suggests constant distribution of particle within 72 hours in study area. 3) We divided the study area into four arbitrary to calculate existent particle within each section between 0 and 72 hour. It was found from the results that the areas were, respectively, range of 20～40 % between east coastline of Gadukdo and Sinjado and convergence of 30～40 % between Sinjado and Dadaepo even though particle keep release from the area.