STUDY OF SEDIMENT CHANGE AFTER OPENING WATER GATE IN THE LAKE SHIHWA, KOREA

摘要

In recent years, water environment of the lake Shihwa has been deteriorating and it has created huge environmental as well as social problems in Korea. In order to identify the possible reasons for the deterioration, investigation is required which can trace the reason of the problems and can recommend the measures to overcome such problems. This article will mainly be focused on water and sediment quality of the lake Shihwa. Based on the field observation and analysis of the collected samples, we will discuss the water quality of the lake Shihwa, considering the parameters such as water temperature, salinity and dissolved oxygen (DO). Similarly, in order to analyze the sediment quality, core samples from three points in the lake area were collected and the particle distribution, total carbonitrogen content, C/N ratio and radioactive strength were measured. Even in autumn, lower values of DO concentration were observed in the near bottom layer of the river mouth and in the front area of BanWeul which is caused by salinocline. Furthermore, the core sample analysis clearly showed the change of sedimentation process on the time basis such as before, during and after the construction of the water gate. The sediment layer has been found to be a good record of the contamination after the completion of the water gate. In other words, the finding of the research enables us to understand the impacts of construction of the water gate which triggered the pollution of the organic matters in the lake.