检索结果-南通市图书馆

Study on the simulation of transparency of Lake Taihu under different hydrodynamic conditions

Science china Earth sciences 2006年第Z1期49卷 162-175页

作者： PANG Yong, LI Yiping & LUO Liancong College of Environmental Science and Engineering, Hohai University, nanjing 210098, china nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210098, china College of Environmental Science and Engineering Hohai University Nanjing China nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China

It was indicated in this study that there were negative relations between the concentrations of suspended solid (SS) and transparency according to the analysis of measured data of Lake Taihu. Their relations in pervious studies were reviewed, which showed that the changes of transparency in Lake Taihu could be reflected by simulating suspended solid concentration (SSC). Measured data showed that the changes of SSC with wind speed were similar at different water *** increased with the increasing of wind speed. Both wave and lake current of Lake Taihu had positive relations with SSC. However, wave was the main factor affecting sediment suspension, while flow took the second place. In this study, a numerical model coupling lake current, wave and SSC of Lake Taihu was developed. In the SS model, the combined effects of wave and current were *** amounts of suspended and deposited sediments near the lake bed surface layer were treated separately. The stochastic characteristics of turbulent flow pulsation near lake beds were also considered, and the start-up conditions of sediment suspension were introduced to the model. The model elucidated the mutual exchange processes between sediment particles in SS and active sediments within and on the bed surface layer. Simulated results showed that lake current had relatively significant effects on the SSC at littoral areas of Lake Taihu, while SSC at the central area of the lake was mainly influenced by wave. The changes of transparency with SSC were simulated for Lake Taihu using this model. Calculated results were validated by measured data with good fitness, which indicated that the model is basically suitable for the simulation and prediction of transparency of Lake Taihu.

关键词： transparency, suspended solid, hydrodynamic, sediment suspension, model.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

不同气候区月蒸散发能力计算模式适用性分析

引用

水文 2004年第5期24卷 1-4,40页

作者：陈喜姜彤河海大学水资源开发教育部重点实验室江苏南京210098 中国科学院南京湖泊与地理研究所江苏南京210008

根据实测气象资料和蒸散发量资料,对几种蒸散发量计算模式进行了对比分析,提出不同气候区计算模式的适用性。以彭曼-蒙蒂斯公式计算的蒸散发量作为参考值,得出Φ20蒸发皿换算成蒸散发能力的折算系数。分析成果对我国水文水资源计算和进... 详细信息

根据实测气象资料和蒸散发量资料,对几种蒸散发量计算模式进行了对比分析,提出不同气候区计算模式的适用性。以彭曼-蒙蒂斯公式计算的蒸散发量作为参考值,得出Φ20蒸发皿换算成蒸散发能力的折算系数。分析成果对我国水文水资源计算和进行气候变化影响评价具有指导意义。

关键词：气候区蒸散发计算模式相关系数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Alkaline phosphatase activity and the phosphorus mineralization rate of Lake Taihu

引用

Science china Earth sciences 2006年第Z1期49卷 176-185页

作者： GAO Guang, ZHU Guangwei, QIN Boqiang, CHEN Jun & WANG Ke nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210008, china Hohai University, nanjing 210098, china nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China Hohai University Nanjing China

The phosphorus fractions, the alkaline phosphatase activity (APA) and other water chemical parameters were concomitantly monitored from April 2003 to October 2004 in different ecotype sites of Lake Taihu. During the stages of algae growth, the phosphorus fractions and their relationships with APA in different ecotype sites were discussed and the phosphorus mineralization rate was calculated. In the water of Lake Taihu, most of the phosphorus (70.2%) could be attributed to the suspended particulate phosphorus, while the dissolved reactive phosphorus (DRP) seems to contribute less than 7%. About 58% of the total phosphorus, however, can be hydrolyzed as inorganic phosphate to compensate for phosphorus deficiency of algae and bacteria growth. During the different algae growth stages, the APA and its Kinetic parameters were varied significantly between different ecotype sites of Lake Taihu. This trend is also visible by comparing the phosphorus mineralization rate,and the most rapidly phosphorus turnover time is only several minutes. The fast recycle of phosphorus can, to some extent, be explained that the phosphorus source of algal blooms. The phytoplankton seems to compensate for phosphorus deficiency by using the alkaline phosphatase to hydrolyze phosphomonoesters.

关键词： Lake Taihu, alkaline phosphatase, kinetic parameters, phosphorus, mineralization rate.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

THREEDIMENSIONAL NUMERICAL SIMULATION OF WINDINDUCED CIRCULATION IN LAKE TAIHU

引用

Journal of Hydrodynamics 2004年第3期16卷 341-349页

作者： LUOLian-cong QINBo-qiang nanjinginstituteofgeographyandlimnology ChineseAcademyofSciencesNanjing210008China

A three-dimensional (3-D) numerical circulation model for shallow-lake ispresented and described in detail in this paper, which employs model-splitting technique in order tocalculate water level, mean-depth velocities and horizontal and vertical velocities at differentdepth simultaneously. The results show the current circulation pattern features four eddies with twoclockwise and two anticlockwise induced by prevailing wind. Opposite wind field will lead toopposite current pattern with phase shifted by 180° The surface convergence zone is located in theupwind area and the surface divergence part in the downwind region, This results in drastic verticalmovement in the two zones and the return currents at the bottom with phase shifted by 180° fromthe surface current vectors. Thus the water level decreases significantly at the leeward side andincreases quickly at the windward part. Verification and calibration for the model were made basedon the water-level and current data observed during the 9711 Storm in Lake Taihu. The predictedresults are in satisfactory agreement with the observed data, which raises the possibility that thismodel can be used to decide the bottom current stress for sediment resuspension and also tosimulate sediment transportation. It can provide a fundamental tool to study the nutrient releasefrom bottom sediment in Lake Taihu.

关键词： numerical simulation three dimensional hydrodynamics lake taihu

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evidence from isotopic geochemistry as an indicator of eutrophication of Meiliang Bay in Lake Taihu, china

引用

Science china Earth sciences 2006年第Z1期49卷 62-71页

作者： LIN Lin, WU Jinglu & WANG Sumin nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210008, china Graduate University of the chinese academy of sciences, Beijing 100039, china nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China Graduate University of the chinese academy of sciences Beijing China

In this paper, Lake Taihu, a large shallow freshwater lake in china, is chosen as an example of reconstruction of eutrophication through the comparison between stable isotopes from dissolved nutrients and plants and water column nutrient parameters and integration of multiple proxies in a sediment core from Meiliang Bay including TN, TP, TOC, C/N, δ15N, δ13C, etc. Differences in aquatic plant species and trophic status between East Taihu Bay and Meiliang Bay are indicated by their variations in δ13C and δ15N of aquatic plants and δ15N of NH4+. A significant influence ofexternal nutrient inputs on Meiliang Bay is reflected in temporal changes in δ 15N of NH4+ and hydro-environmental parameters. The synchronous change between δ13C and δ15N values of sedimented organic matter (OM) has been attributed to elevated primary production at the beginning of eutrophication between 1950 and 1990, then recent inverse correlation between them has been caused by the uptake of 15N-enriched inorganic nitrogen by phytoplankton grown under eutrophication and subsequent OM decomposition and denitrification in surface sediments, indicating that the lake has suffered from progressive eutrophication since 1990. Based on the use of a combination of stable isotopes and elemental geochemistry, the eutrophication of Meiliang Bay in Lake Taihu could be better traced. These transitions of the lake eutrophication respectively occurring in the 1950s and 1990s have been suggested as a reflection of growing impacts of human activities, which is coincident with the instrumental data.

关键词： stable carbon isotope of OM, stable nitrogen isotope, eutrophication, Lake Taihu.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A STUDY ON EQUILIBRIUM COASTAL PROFILES OF THE CLOSE TIDAL FLAT—A Case Study of Fengxian Tidal Flat

引用

chinese Geographical Science 2002年第1期12卷 55-60页

作者： LI Heng peng, YANG Gui shan(nanjing institute of geography and limnology, the chinese academy of sciences, nanjing 210008, P.R. china) nanjing institute of geography and limnology the Chinese Academy of Sciences Nanjing 210008

The article analyses the temporal spatial changes of profiles by EOF (Empirical Orthogonal Function) analysis and DTM analysis of GIS. These profiles, which are not affected by engineering, are chosen from the coast with successive field monitoring data from 1990 to 1999. Temporal and spatial EOF indicates the obvious stability of coast profile parameters in Fengxian tidal flat. In spatial scale, high tidal flats and deep water terraces are in a balance state while upper clino with steep slopes are sensitive and the stability is easy to be destroyed. In temporal scale, the erosion and deposition in this area are kept in balance in a whole. There are almost no change below 8- 9.5m. At the same time, it is the lower limit of tidal affection and the erosion and deposition process from it to high tidal flat keep in balance for many years. So the closure depth is appointed to from 8m to 9.5 m (Wusong datum mark).

关键词：经验正交函数分析空间分析 GIS 平衡剖面海岸剖面空间分析 DTM

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental study on phosphorus release from sediments of shallow lake in wave flume

引用

Science china Earth sciences 2006年第Z1期49卷 92-101页

作者： SUN Xiaojing,ZHU Guangwei, LUO Liancong & QIN Boqiang nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210008, china Graduate School of chinese academy of sciences, Beijing 100039, china nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China Graduate School of chinese academy of sciences Beijing China

Influence of wave on sediment resuspension and nutrients release from sediments, collected from Lake Taihu and Lake Chaohu, was studied in flume experiments. Under strong-wave conditions, concentrations of suspended solids (SS), total phosphorus (TP) and dissolved total phosphorus (DTP) in overlying water were increased significantly following the sediments re-suspension. During the experiments on sediments of Lake Taihu and Lake Chaohu, TP concentrations increased 6 times and 3 times, and DTP concentration increased 100% and 70% more than it in presuspension, respectively. Concentration of soluble reactive phosphorus (SRP) of experiment on sediment of Lake Taihu increased 25%. During the massive sediment suspension, the dissolved phosphorus in pore water and much of the phosphorus adsorbed by the sediment particles were released into overlying water. The phenomena in this wave flume experiment are quite similar to the situation observed in situ of Lake Taihu. The critical wave stresses of sediment re-suspension are nearly equal. The change of concentrations of SS, TP, and SRP was the same as that in situ *** study showed that concentrations of TP and SRP in lake water could be increased significantly by wave disturbance. Phosphorus release was significantly enhanced by wave disturbance at the beginning of massive sediment re-suspension, but decreased later.

关键词： shallow lakes, wave disturbance, internal release, phosphorus, wave flume experiment.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New progress of lake sediments and environmental changes research in china

引用

chinese Science Bulletin 1999年第19期44卷 1744-1754页

作者： WANG Sumin and ZHANG ZhenkeLaboratory of Lake Sediment and Environment, nanjing institute of geography and limnology, chinese academy of sciences , nanjing 210008, china Department of geography and Oceanology, nanjing University , nanjing 210093 , china Laboratory of Lake Sediment and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China Department of geography and Oceanology Nanjing University Nanjing China

Environmental change recorded by lake sediments is one of the important branches of the past global changes study. The new progress of lake sediments and environmental changes in china since the late 1980s has been comprehensively discussed. The highlights emphasized are Asian paleomonsoon migration reflected by lake level fluctuation, uplift of the Qinghai-Xizang Plateau recorded by lacustrine sediments, saltlake sediments and

关键词： lake sediments environmental change.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of sediment resuspension on underwater light field in shallow lakes in the middle and lower reaches of the Yangtze River:A case study in Longgan Lake and Taihu Lake

引用

Science china Earth sciences 2006年第Z1期49卷 114-125页

作者： ZHANG Yunlin, QIN Boqiang, ZHU Guangwei, GAO Guang, LUO Liancong & CHEN Weimin nanjing institute of geography & limnology, chinese academy of sciences, nanjing 210008, china Graduate School of chinese academy of sciences, Beijing 100039, china nanjing institute of geography & limnology Chinese Academy of Sciences Nanjing China Graduate School of chinese academy of sciences Beijing China

Based on three continuous in situ underwater light field measurement under different wind waves conditions in Longgan Lake, Meiliang Bay of Taihu Lake in July 2003 and littoral zone near TLLER in July 2004, respectively, the effects of sediment resuspension caused by wind waves on PAR diffuse attenuation, absorption coefficients and euphotic depths are analyzed. In Longgan Lake, PAR diffuse attenuation coefficients during small, middle and large wind waves were 1.74, 2.02 and 2.45 m-1, respectively, and the corresponding PAR spectral diffuse attenuations ranged from 0.98 to 2.97, 1.34 to 3.95 and 1.80 to 5.40 m-1, respectively. In Meiliang Bay, PAR diffuse attenuation coefficients were 2.63, 3.72, 4.37 m-1 during small, middle and large wind waves. PAR diffuse attenuation coefficients increased by 41% and 66% from small to middle, large wind waves, *** coefficients integrated over the range of PAR of CDOM, phytoplankton were 0.26, 0.28 m-1;0.76, 0.49 m-1, respectively during middle and large wind waves. Absorption coefficients integrated over the range of PAR of non-algal particulate matter and total suspended particulate matter increased from 0.94 to 1.73 m-1, and from 1.70 to 2.22 m-1, respectively during middle and large wind waves. Relative contributions of absorption coefficients of non-algal particulate matter to total absorption coefficient integrated over the range of PAR were 44.14%, 65.05%, respectively, during middle and large wind waves. PAR euphotic depths decreased by 0.40, 0.19, 0.20 m from middle to large wind waves in Longganhu Lake, Meliang Bay and littoral zone near TLLER. Significant correlations were found between transparency, PAR diffuse attenuation coefficients, euphotic depths and total suspended particulate matter, wind velocity, wave height. Most significant correlations were found between transparency, PAR diffuse attenuation coefficients, euphotic depths and inorganic suspended particulate matter but low correlations

关键词： shallow lake, Taihu Lake, diffuse attenuation coefficient, absorption coefficient, total suspended particulate matter.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

DIATOM COMMUNITY SUCCESSION AND NUTRIENT EVOLUTION RECORDED FROM A SEDIMENT CORE OF THE LONGGAN LAKE, A LARGE SHALLOW LAKE IN EAST china

引用

水生生物学报 2006年第6期30卷 702-710页

作者： DONG Xu-Hui and YANG Xiang-Dong (nanjing institute of geography & limnology, the chinese academy of sciences, nanjing 210008, china) nanjing institute of geography & limnology the Chinese Academy of Sciences Nanjing 210008

The Longgan Lake is a shallow mesotrophic macrophyte-dominated lake. According to the high-resolution diatom research from its sediment core, the diatom community succession was built, and the total phosphorus (TP) and chlorophyll-a (Chl-a) concentration were quantitatively reconstructed for the past 2000 years, based on the diatom-TP and diatom-Chla transfer functions. The shifts of diatom assemblages also mirrored the developments of aquatic plant, reflecting the characters of aquatic ecosystem evolution. The inferred epilimnetic TP concentration fluctuated within a small range of 36 to 62μg/L, indicating the lake remained a relative stable mesotrophic status in the long historical period. The periodical variations of the diatom assemblage and trophic status suggest a mitigating function of shallow macrophyte-dominated lakes to nutrient input. The changes of lakes’ trophic status don’t linearly respond to the human disturbance in the catchment. The dynamics mechanism of phosphorus in macrophyte-dominated lakes, as inferred from diatoms, will provide a scientific foundation for the prediction of trophic status change in a shallow lake, as well as the lake ecological restoration and management decisions.

关键词： Diatom assemblage Nutrient Quantitative reconstruction Aquatic macrophyte Longgan Lake

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：