1. Senior Researcher, National Institute of Environmental Research, Nakdong River Environment Research Center, 24, Pyeongri-1gil, Dasan-myeon, Goryeong-gun, Gyeongsangbuk-do 717-873, Republic of Korea.
2. Professor, Dept. of Civil Engineering, Changwon National Univ., 9 Sarim, Changwon, Gyeongnam 641-773, Republic of Korea (corresponding author).