Seasonal-Spatial Distribution and Long-Term Variation of Transparency in Xin'anjiang Reservoir: Implications for Reservoir Management.
Water transparency is a useful indicator of water quality or productivity and is widely used to detect long-term changes in the water quality and eutrophication of lake ecosystems. Based on short-term spatial observations in the spring, summer, and winter and on long-term site-specific observation from 1988 to 2013, the spatial, seasonal, long-term variations, and the factors affecting transparency are presented for Xin'anjiang Reservoir (China). Spatially, transparency was high in the open water but low in the bays and the inflowing river mouths, reflecting the effect of river runoff. The seasonal effects were distinct, with lower values in the summer than in the winter, most likely due to river runoff and phytoplankton biomass increases. The transparency decreased significantly with a linear slope of 0.079 m/year, indicating a 2.05 m decrease and a marked decrease in water quality. A marked increase occurred in chlorophyll a (Chla) concentration, and a significant correlation was found between the transparency and Chla concentration, indicating that phytoplankton biomass can partially explain the long-term trend of transparency in Xin'anjiang Reservoir. The river input and phytoplankton biomass increase were associated with soil erosion and nutrient loss in the catchment. Our study will support future management of water quality in Xin'anjiang Reservoir.
Chun'an Environmental Monitoring Station, Hangzhou 311700, China. caepb@126.com.
Zhixu
Z
Wu
Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. ylzhang@niglas.ac.cn.
Yunlin
Y
Zhang
Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. yohnchou917251@126.com.|College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. yohnchou917251@126.com.
Yongqiang
Y
Zhou
Institute of Environmental Protection Science, Hangzhou 310014, China. lmllyx@163.com.
Mingliang
M
Liu
Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China. kshi@niglas.ac.cn.
Kun
K
Shi
Institute of Environmental Protection Science, Hangzhou 310014, China. yzm0571@163.com.
Zuoming
Z
Yu
D061006:Bays; D018533:Biomass; D002681:China; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005068:Eutrophication; D005618:Fresh Water / Q000737:chemistry*; D060106:Lakes; D010839:Phytoplankton; D011891:Rain; D045483:Rivers; D012621:Seasons; D062206:Spatial Analysis; D060753:Water Quality
D002734:Chlorophyll; D000077194:Chlorophyll A
Xin’anjiang Reservoir; chlorophyll a; long-term trend; rainfall; water transparency