title: Factors dominating stratification cycle and seasonal water quality variation in a Korean estuarine reservoir.
abstract: A comprehensive monitoring program was conducted during 2005-2007 to investigate seasonal variations of hydrologic stability and water quality in the Yeongsan Reservoir (YSR), located at the downstream end of the Yeongsan River, Korea. A principal component analysis (PCA) was performed to identify factors dominating the seasonal water quality variation from a large suite of measured data--11 physico-chemical parameters from 48 sampling sites. The results showed that three principal components explained approximately 62% of spatio-seasonal water quality variation, which are related to stratifications, pollutant loadings and resultant eutrophication, and the advective mixing process during the episodic rainfall-runoff events. A comparison was then made between YSR and an upstream freshwater reservoir (Damyang Reservoir, DYR) in the same river basin during an autumn season. It was found that the saline stratification and pollutant input from the upstream contributed to greater concentrations of nutrients and organic matter in YSR compared to DYR. In YSR, saline stratification in combination with thermal stratification was a dominant cause of the longer period (for two consecutive seasons) of hypoxic conditions at the reservoir bottom. The results presented here will help better understand the season- and geography-dependent characteristics of reservoir water quality in Asian Monsoon climate regions such as Korea.
authors.affiliation: Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 500-712, Korea.
authors.forename: Young Geun
authors.initials: YG
authors.lastname: Lee
authors.forename: Joo-Hyon
authors.initials: JH
authors.lastname: Kang
authors.forename: Seo Jin
authors.initials: SJ
authors.lastname: Ki
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Cha
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Cho
authors.forename: Yun Seok
authors.initials: YS
authors.lastname: Lee
authors.forename: Yongeun
authors.initials: Y
authors.lastname: Park
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Joon Ha
authors.initials: JH
authors.lastname: Kim
mesh_terms: D004784:Environmental Monitoring / Q000379:methods; D005068:Eutrophication; D005618:Fresh Water / Q000737:chemistry*; D025341:Principal Component Analysis; D056910:Republic of Korea; D012621:Seasons; D014873:Water Pollutants / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
chemical_list: D014873:Water Pollutants