Estimation of internal nutrient release in large shallow Lake Taihu, China
文献类型：期刊论文
| 作者 | Qin Boqiang; Zhu Guangwei; Luo Liancong; Gao Guang; Gu Binhe |
| 刊名 | SCIENCE IN CHINA SERIES D-EARTH SCIENCES
 |
| 出版日期 | 2006 |
| 卷号 | 49期号:4页码:38-50 |
| 关键词 | shallow lake eutrophication internal loading sediment nutrient dynamic turbulence |
| ISSN号 | 1006-9313 |
| 英文摘要 | Based on field investigation of wave, sediment suspension and the changes in nutrient concentration of the water column in Lake Taihu, China, we proposed two release models to quantify nutrient release under static and dynamic conditions, respectively. Under static conditions, nutrient release from sediments to the overlying water mainly depends on chemical diffusion induced by concentration gradient, in which the nutrient release is controlled by the temperature, dissolved oxygen concentration in the sediment-water interface, oxidation-reduction potential and the concentration difference between porewater and overlying water. Under dynamic condition (or disturbed condition), both dissolved and particulate nutrients in sediments are released into the water column because of wind-induced sediment suspension. The amount of nutrient release under dynamic conditions is larger than that under the static condition. The release of dissolved nutrients, however, does not increase because the wind induced turbulence made oxidation of metallic elements such as Fe (ferric iron), Mn which are capable of precipitating soluble reactive phosphate (SRP). Under dynamic conditions, therefore, the release of total phosphorus (TP) increases dramatically but the release of SRP is close to those under static conditions. In sediments of Lake Taihu, high Fe content leads to a high ratio of Fe to P contents in sediments (Fe:P ratio). Under dynamic conditions, therefore, nutrient release is controlled by the intensity of disturbance, sediment consolidation and nutrient content in sediments. As for dissolved nutrients, especially SRP, the release is also controlled by the intensity of dynamic re-oxidation, Fe content in sediments and nutrient concentration gradient between porewater and overlying water. Based on these two release modes, the release flux in Lake Taihu has been estimated. In the static condition (i.e. laboratory experimental condition), total release of NH4+-N for whole lake is ca. 10,000 ton/a, and PO43--P is ca. 900 ton/a. In the dynamic condition, nutrient release following sediment suspension was estimated according to three different intensities of wind forcing which were defined as "calm" (wind speed is less than 2 m/s), "gentle" (wind speed is greater than 2 m/s and less than 6 m/s) and "gust" (wind speed is greater than 6 m/s). The release rate in the condition of "calm" was estimated in terms of the nutrient release in the laboratory experimental static condition; whereas the release rate in conditions of "gentle" and "gust" was estimated in terms of measurement during sediment resuspension conducted in flume experiments. With the observation of wind velocity and frequency in 2001, each type of wind forcing took the frequency of 12%, 82% and 6% for "calm", "gentle" and "gust", respectively. The yearly release of nitrogen was 81,000 ton and phosphorus was 21,000 ton, which is about 2-6 folds of annual external loading, respectively. |
| 公开日期 | 2012-03-08 |
| 源URL | [http://159.226.73.51/handle/332005/2999]  |
| 专题 | 南京地理与湖泊研究所_湖泊室 |
| 推荐引用方式 GB/T 7714 | Qin Boqiang,Zhu Guangwei,Luo Liancong,et al. Estimation of internal nutrient release in large shallow Lake Taihu, China[J]. SCIENCE IN CHINA SERIES D-EARTH SCIENCES,2006,49(4):38-50. |
| APA | Qin Boqiang,Zhu Guangwei,Luo Liancong,Gao Guang,&Gu Binhe.(2006).Estimation of internal nutrient release in large shallow Lake Taihu, China.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,49(4),38-50. |
| MLA | Qin Boqiang,et al."Estimation of internal nutrient release in large shallow Lake Taihu, China".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 49.4(2006):38-50. |
入库方式： OAI收割
来源：南京地理与湖泊研究所
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