Trophic conditions of man-made reservoirs within keum-river watershed and geographical dynamics in empirical relations of chlorophyll-a to some other parameters = 금강수계 내 인공호의 영양상태 및 엽록소-a와 수질변수들간의 경험적 상관관계에서의 지리적 변동

Abstract

In this study, we identified spatial and temporal patterns of reservoir trophic state within Keum-river watershed and analyzed correlations between chlorophyll-a (Chla) and water quality parameters including conductivity and total phosphorus (TP). The reservoirs were separated into three trophic categories by the criteria of TP: 2 oligotrophic (9.3~~9.4 μg L-1), 15 mesotrophic (10.3~~19.2 μg L-1), and 14 eutrophic reservoirs (38.9~~117.1 μg L-1). Water quality parameters such as conductivity, TP, and Chla reflected rainfall patterns, and the patters of annual mean TP were similar to the variation of annual mean Chl-a. Empirical models of Chl-a against TP in reservoirs showed that statistical significance (p/0.05) occurred in only some seasons and the trophic relations were modified by a washing-out effect or high non-algal light attenuation.