This study was focused on estimating instream flow, and its optimal alternative for securing the required total amount of instream flow was also researched in order to restore ecosystems and riverine aesthetics of the Mugeo Stream, the first tributary of the Taewha River flowing through the center of Ulsan. In this study the hydraulic and hydrologic conditions and water quality were investigated at specific channel reaches and representative stations of the Mugeo Stream to determine a proper estimate of instream flow. And riverine functions, such as the minimum flow, water quality conservation, fish habitat, and recreation, were considered to restore the environmental functions of the stream. As a result, the total amount of 11,500㎥/day was set as the target instream flow for the Mugeo Stream. It was chosen as the optimal alternative for securing the total external supply of 10,000㎥/day which have to be transfered from the riverbed flow diverted through the Taewha Main river at upstream of Samho bridge. The water quality throughout the Mugeo Stream channels will be improved considerably to 3-4 mg/l of BOD standard if the target instream flow is supplied and sewage is intercepted by the sanitary sewage system.

본 연구는 미동산 내 형성되어 있는 소하천 주변의 식생정보와 식물상을 객관적으로 분석하여 자연형 하천복원계획을 위한 기초 자료 제공과 더불어 복원용 소재개발을 위해 수행되었다. 본 지역의 식물상은 33과 84속 81종 14변종 등 총 95분류군이 확인되었다. 출현한 귀화식물은 오리새, 미국개기장, 소리쟁이, 취명아주, 토끼풀, 수박풀, 큰달맞이꽃, 돼지풀, 미국쑥부쟁이, 개망초, 망초, 기생초, 서양민들레, 미국가막사리, 코스모스 등 총 15분류군이었다. 식생군락은 달뿌리풀이 전체 우점종으로 판명되었고 부 우점종이 갯버들, 갈풀, 미국가막사리, 고마리로 관찰되었다. 하천복원을 위해서는 생물종다양성과 서식처 등을 고려해야 할 것이며, 달뿌리풀, 갯버들, 고마리, 큰물칭개나물 등의 다양한 소재 이용이 필요할 것으로 판단된다.

The purpose of this study is to present the model of ecological restoration through analysis on the condition of hydrach succession process in brackish water lake. To this study, we investigate and research the present condition of brackish water lake in South Korea. Most brackish water lake in South Korea have characteristics that is come into being malignant hydrach succession. Many lakes were reclaimed to increase foodstuff production. And river conservation work seperate lakes from the ocean. In a embryological view, most lakes based on the brackish water lakes. But present lakes show many different types such as a fresh water lake, a salt lake, a brackish water lake, a swamp, and a marshland. As a result, brackish water lakes have greatly damaged by diverse artificial interventions to promote people's activities. Therefore, in order to manage brackish water lakes systematically, criteria of lake preservation must be coincide with the present conditions of hydrach succession in each lake.