Temporal and spatial changes in nutrients and chlorophyll-a in a shallow lake, Lake Chaohu, China： An ll-year investigation

• Published in: 环境科学学报：英文版 no. 6; pp. 1117 - 1123
• Main Author: Libiao Yang Kun Lei Wei Meng Guo Fu Weijin Yan
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: 中国; 叶绿素a; 季节性变化; 巢湖; 平均浓度; 时空变化; 水质参数; 营养物质
• ISSN: 1001-0742; 1878-7320

Temporal and spatial changes of total nitrogen （TN）, total phosphorus （TP） and chlorophyll-a （Chl-a） in a shallow lake, Lake Chaohu, China, were investigated using monthly monitoring data from 2001 through 2011. The results showed that the annual mean concentration ranges of TN, TP, and Chl-a were 0.08-14.60 mg/L, 0.02-1.08 mg/L, and 0.10-465.90 ~tg/L, respectively. Our data showed that Lake Chaohu was highly eutrophic and that water quality showed no substantial improvement during 2001 through 2011. The mean concentrations of TP, TN and Chl-a in the western lake were significantly higher than in the eastern lake, which indicates a spatial distribution of the three water parameters. The annual mean ratio of TN：TP by weight ranged from 10 to 20, indicating that phosphorus was the limiting nutrient in this lake. A similar seasonality variation for TP and Chl-a was observed. Riverine TP and NH4＋ loading from eight major tributaries were in the range of 1.56× 10^4-5.47 × 10^4 and 0.19 × 104-0.51 × 10^4 tons/yr over 2002-2011, respectively, and exceeded the water environmental capability of the two nutrients in the lake by a factor of 3-6. Thus reduction of nutrient loading in the sub-watershed and tributaries would be essential for the restoration of Lake Chaohu.