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

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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： silted tidal flat EOF analysis equilibrium profile spatial analysis

New progress of lake sediments and environmental changes research in China

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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.

APPLICATION　OF　GIS　IN　ANALYZING　ECOSYSTEM＇S　RELATIVE　SENSITIVITY　TO　ACID　DEPOSITION

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Chinese Geographical Science 1996年第4期6卷 359-363页

作者： He Longhua Yans Hongwei(nanjing institute of geography & limnology, the Chinese Academy of Sciences,nanjing 210008, PRC) nanjing institute of geography & limnology the Chinese Academy of Sciences Nanjing PRC

This paper decribo an application of GIS technology in estimating estem's relive sensitivity to acid despition. East China is selected as the research area. Four variable layers, which are ha rock, soil buffering ability, vegetation type and soil humidity, are used in the process. Five grades are separated in this research. The sensitivity mapping is also discussed in this paper.

关键词： acid deposition sensitivity index geographic information system

Alkaline phosphatase activity and the phosphorus mineralization rate of Lake Taihu

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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 Chinese Acad Sci Nanjing Inst Geog & Limnol Nanjing 210008 Peoples R China Hohai Univ Nanjing 210098 Peoples R 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.

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

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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 Hohai Univ Coll Environm Sci & Engn Nanjing 210098 Peoples R China Chinese Acad Sci Nanjing Inst Geog & Limnol Nanjing 210098 Peoples R 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 hydrodynamlc sediment suspension model.

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

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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 Chinese Acad Sci Nanjing Inst Geog & Limnol Nanjing 210008 Peoples R China Chinese Acad Sci Grad Univ Beijing 100039 Peoples R 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.

MAJOR PROBLEMS OF SUSTAINABLE DEVELOPMENT ALONG THE BANK AREA OF THE CHANGJIANG RIVER

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Chinese Geographical Science 2000年第2期10卷 97-104页

作者： YANG Gui-shan(nanjing institute of geography and limnology,the Chinese Academy of Sciences, Nanjng 210008, P R. China) nanjing institute of geography and limnology the Chinese Academy of Sciences Nanjing P. R. China

Developing the Changjiang(Yangtze) River and building a developed economic zone along the bank area of the Chanajiang River is a great strategic decision of the national macroeconomic development distribution. This decision has both given an impetus to fast development of the regional economy and exacerbated the contradiction among economy and resources and environment. In this paper, some major problems ekisting in economic sustainable development, such as scattered industrial structure, duplicated construction of the great projects, enlarging the development gap of the regional economy and deteriorated environment etc., have been studied. The results show that scattered structure and duplicated distribution of some key industries and projects, especially automobile, electronics and petrochemical industry and communication, power installations, is one of the reasons for low industrial economic benefit; the great development gap among upper, middle and lower reaches areas are enlarging since the 1990’ s; soil erosion, nood disaster and environmental pollution are still exacerliating due to unreasonable over-development. Based on the above analysis, this paper brings out some countermeasures and proposals for increasing the ability of regional sustainable development, including transregional reorganization of industrial structure linking by assets and speeding the process of regional economy integration; gradually controlling and reducing the development gap arnong upper, middle and lower reaches areas through regional cooperation on a mutually beneficial basis; as well as strengthening ecological construction and environmental protection and increasing environmental bearing capacity etc.

关键词： the bank area of the Changjiang River sustainable development structure problems environment deterioration

Effects of main range and strength factors on change of COD in a shallow lake

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Journal of Environmental Sciences 1998年第1期10卷 51-57页

作者： Fan Cheng xin nanjing institute of geography and limnology,Chinese Academy of Sciences,nanjing 210008,China

A model involving the relationship between non conservative matter (COD) and main range factors(loading, water stage) and strength factor (temperature) in a shallow lake has been established on the basis of less change of water stage area curve in certain extent, broader distribution in pollution sources and more homogeneous in quantity of heat. The effects of COD inflow and /or outflow, and hydro meterological factors upon COD content in Lake Taihu were calculated and simulated under the actual situation of the loadings and regimen. The results simulated by using the model are in better agreement with the observed field data. The error of the model was also discussed.

关键词： COD model environmental factor effects shallow lake.

Assessment of coastal vulnerability to environmental change in Jiangsu coastal plain

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Journal of Geographical Sciences 2001年第1期11卷 24-33页

作者： YANG Gui-shan, SHI Ya-feng, ZHANG Chen, LIANG Hai-tang (nanjing institute of geography and limnology, CAS, nanjing 210008, China) nanjing institute of geography and limnology CAS Nanjing China

Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the Yangtze River Delta in China, is most vulnerable to sea level rise and exacerbating coastal hazards. This paper develops the method of delimiting vulnerable scope and assessing coastal vulnerability through field observations and sampling and by applying remote sensing and GIS, which are suitable for great river delta and coastal plains with large area, relative complex micro-geomorphology and the protection of seawall. Applying this method, the coastal vulnerability of the Jiangsu coastal plain to relative sea level rise (approximately 50 cm up to the year 2050) and exacerbating storm surges have been assessed. The results show that, up to the year 2050, the Jiangsu coastal plain will probably lose 12.8 % of tidal flats (about 5.8x104 hm2) and 7.9 % of cultivated land (about 7.2x104 hm2). Meanwhile, 2.0 % of population, 3.8 % of original value of fixed assets, 3.2% of GDP (Gross Domestic Product), 40.3 % of salt industry and 5.8 % of aquiculture respectively will be affected due to coastal environmental change.

关键词： coastal vulnerability assessment vulnerable scope coastal environmental change Jiangsu coastal plain