Temporal and spatial changes in nutrients and chlorophyll-a in a shallow lake,Lake Chaohu, China: An 11-year investigation

作     者：Libiao Yang Kun Lei Wei Meng Guo Fu Weijin Yan 

作者机构：River and Coastal Environment Research CenterChinese Research Academy of Environmental Sciences Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2013年第25卷第6期

页      面：1117-1123页

核心收录：

学科分类：08[工学] 081501[工学-水文学及水资源] 0815[工学-水利工程] 

基　　金：supported by the National Science-technology Support Project of China (No.2010BAC69B02) the National Natural Science Foundation of China (No. 41203080) 

主　　题：eutrophication Lake Chaohu nitrogen phosphorus 

摘      要：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.