A comparative study on the phytoplankton dynamics between two large artificial reservoirs in Korea

摘要

Artificial reservoirs are built in downstream river valleys, so that their morphology and water quality are influenced by valley characteristics. These physical characteristics affect biological processes in many complex ways, the most important of which are light and nutrient availability (Wetzel 1990). Artificial reservoirs in Korea can be divided into river-type or lake-type, though the characteristics of each may not be universally applied to all reservoirs. According to the results of 61 surveyed Korean reservoirs, features of lake-type reservoirs were categorized by: nutrient uptake by algae after rainfall; retention time over 60 days, and; chlorophyll-a concentration of winter season higher than that of summer season. River-type reservoirs, however, were categorized by: nutrients wash out after rainfall; algal growth was low in rainy season because of high turbidity and wash out (Kong 1997a). The potential for algal blooms in each reservoir type depends on the nutrient load and rainfall amount. Further, the effect of autochthonous organic matter produced by the photosynthesis of both macrophyte and plankton in lake-type reservoirs was relatively larger than that of river-type reservoir (Han et al. 2002).