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Preliminary study on assessment of nutrient transport in the Taihu Basin based on SWAT modeling

Science china Earth sciences 2006年第z1期49卷 135-145页

作者： LAI Geying, YU Ge & GUI Feng nanjing institute of {2. & limnology, chinese academy of sciences, nanjing 210008, china The Graduate School of the chinese academy of sciences, Beijing 100039, china Key Lab of Poyang Lake Ecological Environment and Resource Development, Jiangxi Normal University, Nanchang 33002., china 1. nanjing institute of {2. & limnology Chinese Academy of Sciences Nanjing 210008 China2. The Graduate School of the Chinese Academy of Sciences Beijing 100039 China3. Key Lab of Poyang Lake Ecological Environment and Resource Development Jiangxi Normal University Nanchang 330027 China

With the Taihu Basin as a study area, using the spatially distributed and mechanism-based SWAT model, preliminary simulations of nutrient transport in the Taihu Basin during the period of 1995～2.02.has been carried out. The topography, soil, meteorology and land use with industrial point pollution discharge, the loss of agricultural fertilizers, urban sewerage, and livestock drainages were all considered in the boundary conditions of the simulations. The model was calibrated and validated against water quality monitoring data from 2.01 to 2.02. The results show that the annual total productions of nitrogen (TN) and phosphorus (TP) into Lake Taihu are 40000t and 2.00t respectively. Nutrient from the Huxi Region is a major resource for Lake Taihu. The non-point source (surface source) pollution is the main form of catchment sources of nutrients into Lake Taihu,occupied TN 53% and TP 56% respectively. TN and TP nutrients from industrial point pollution discharge are 30% and 16%, and sewerage in both forms of point source and non-point source are TN 31% and TP 47%. Both the loss of agricultural fertilizers and livestock drainages from the catchment should be paid more attention as an important nutrient source. The results also show that SWAT is an effective model for the simulation of temporally and spatially nutrient changes and for the assessment of the trends in a catchment scale.

关键词： Taihu Basin, nutrients, catchment resource inputs, SWAT model, simulation.

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Dating sediments on several lakes inferred from radionuclide profiles

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Journal of Environmental sciences 1998年第1期10卷 58-65页

作者： Xiang Liang Lake Sediment and Environment Laboratory,nanjing institute of {2. & limnology, chinese academy of sciences,nanjing 210008,china

In this paper, several sediment cores from three lakes (Gucheng Lake, Dianchi Lake and Dabusopao Lake) in the different regions of china were dated radiometrically by 2.0 Pb, 137 Cs and in Dianchi also by 2.1 Am. The study shows that the profiles of 137 Cs in lake sediment of china generally have 2.4 distinct chronological markers, i.e. the onset of fallout in 1954 and peak fallout in 1963, 1974 and 1986. As many places of the northern hemisphere, the peak fallout in 1963 was the result of the atmospheric atomic weapons test. But in some areas of china, there may be have one or two other peaks of 137 Cs fallout, one can derive from Chernobyl fallout in 1986 and the other is caused by the nuclear testing fallout in early 1970s. So in these areas, the profiles of 137 Cs can have 2.or 3 peaks as the time markers. 2.1 Am, which is another fallout product from nuclear weapons testing, also provides a useful dating marker in Dianchi. These time markers are of considerable value to confirm 2.0 Pb dates in the three lakes. Despite there are some questions remain concerning the interpretation of these radionuclide records in lake sediments, coupling with 2.0 Pb and 137 Cs (and/or 2.1 Am) is suggested to be a valuable limnological tool for establishing sediment chronologies for the lake sediments in china.

关键词： lake sediment radionuclide dating method.

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Nutrient fluxes induced by disturbance in Meiliang Bay of Lake Taihu

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Science china Earth sciences 2006年第z1期49卷 186-192页

作者： LUO Liancong, QIN Boqiang, ZHU Guangwei, SUN Xiaojing, HONG Dalin, GAO Yajun & XIE Rui nanjing institute of {2. & limnology, chinese academy of sciences, nanjing 210008, china nanjing Hydraulic Research institute, Ministry of Water Resources, nanjing 2.002., china 1. nanjing institute of {2. & limnology Chinese Academy of Sciences Nanjing 210008 China2. Nanjing Hydraulic Research Institute Ministry of Water Resources Nanjing 210024 China

A wave flume experiment was conducted to study nutrient fluxes at water-sediment interface of Meiliang Bay under different hydrodynamic conditions. The results reveal that hydrodynamics has remarkable effects on nutrient fluxes in this area. With a bottom wave stress of 0.019 N m-2.(equivalent to disturbance caused by wind SE 5-7 m s-1 at the sediment sample site of Meiliang Bay), the fluxes of TN, TDN and NH4+-N were separately 1.92. 10-3, -1.81 × 10-4 and 5.2.× 10-4 mg m-2.s-1(positive for upward and negative for downward), but for TP, TDP and SRP, the fluxes were 5.69 × 10-4, 1.68 × 10-4 and -1.2. × 10-4 mgm-2.s-1. In order to calculate the released amount of nutrients based on these results, statistic analysis on the long-term meteorological data was *** result shows that the maximum lasting time for wind SE 5-7 m s-1 in this area is about 15 h in summer. Further calculation shows that 111 t TN, 32.t NH4+-N, 34 t TP and 10 t TDP can be released into water (the sediment area was 47.45% of the whole surface area), resulting in concentration increase of 0.02., 0.007, 0.007 and 0.002.mg L-1 separately. With stronger disturbance (bottom wave stress is 0.2.7 N m-2.which is equivalent to disturbance caused by wind SE 10-11 m s-1 at the same site), there has been significant increase of nutrient fluxes (1.16× 10-2. 6.76×10-3, 1.14× 10-2.and 2.14× 10-3 mgm-2.s-1 for TN, DTN and NH4+-N and TP). The exceptions were TDP with flux having a decrease (measured to be 9.54× 10-5 mgm-2.s-1 ) and SRP with flux having a small increase (measured to be 5.42.× 10-5 mgm-2.s-1). The same statistic analysis on meteorological data reveal that the maximum lasting time for wind SE 10-11 m s-1 is no more than 5 h. Based on the nutrient fluxes and the wind lasting-time, similar calculations were also made suggesting that 2.2.t TN, 134.9 t TDN, 2.8 t NH4+-N, 42.7 t TP, 2.0 t TDP and 1.1 t SRP will be released from sediment at this hydrodynamic condition resulting in the concentration

关键词： hydrodynamics disturbance water-sediment interface nutrient release flux Lake Talhu.

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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 2.0098, china nanjing institute of geography & limnology, chinese academy of sciences, nanjing 2.0098, 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.

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Simulation　of　sludge－dredging　effects　in　controlling　nutrient　release　of　LakeKasumigaura　with　large－size　core　samples

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Journal of Environmental sciences 1996年第4期8卷 385-389页

作者： Fan Chengxin (nanjing institute of {2. and limnology, chinese academy of sciences,nanjing 210008,china) Morihiro AIZAKI Kunio KOHATA(The National institute for Environmental Studies, Tsukuba), Japan nanjing Inst. Geogr. and limnology Chinese Academy of Sciences Nanjing 210008 China Natl. Inst. for Environ. Studies Tsukuba Japan

Nutrient release from the dredged and undredged sediments in Lake Kasumigaura were simulated under the laboratory control conditions with large-size core samples. It was found that phosphate and ammonia release fluxes are less in aerobic than those in anaerobic. In different simulated dredged depth, the phosphate release showed large divergence in the anaerobic than in the aerobic. There was a larger accumulated release of phosphate and ammonia at actual dredged (St. B) than the undredged (St. A) in anaerobic condition. This showed that the sludge-dredging was effective of controlling phosphorus and nitrogen release. A preliminary assessment is drawn from the experiments that the sludge-dredging work in Tsuchiura Bay of Lake Kasumigaura can reduce about 15. 9% of phospbate and 56. 2. of anunonia release from the sediments respectively.

关键词： sludge-dredging nutrient release aerobic and anaerobic conditions core samples Lake Kasumigaura.

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The reconstruction and interpretations of lake status at 6 ka and 18 ka *** inland mainland Asia

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chinese Science Bulletin 1998年第14期43卷 1145-1157页

作者： QIN Boqiang 1, SHI Yafeng 1 and YU Ge 2. 3 1. nanjing institute of {2. & limnology, chinese academy of sciences, nanjing 210008, china 2. Dynamic Palaeoclimatology, Lund University, PO Box 117, S 2.1 00, Lund, Sweden 3. Department of nanjing institute of {2. & Limnolagy Chinese Academy of Sciences Nanjing China Dynamic Palaeoclimatology Lund University Lund Sweden Department of Geology and Ocean sciences Nanjing University Nanjing China

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi arid mainland Asia at 6 and 18 ka B.P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 18 ka B.P., but low or intermediate water stands at 6 ka B.P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 18 ka B.P. and significantly high one at 6 ka B.P. The lowering of lake level at 18 ka B.P. was caused by the weakened summer monsoon and the high lake level at 6 ka B.P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B.P. but became similar to that in northwestern Asia at 18 ka B.P. Thus this zone became a transitional sector from the monsoon to the westerlies.

关键词： lake status inland mainland Asia westerlies monsoon.

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Discovery of Cathaysiodendron Lee from the Early Carboniferous of Jingyuan,Gansu,western china

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Progress in Natural Science:Materials International 2004年第10期14卷 63-66页

作者： WANG Jun and WU Xiuyuan (nanjing institute of Geology and Palaeontology,{2. academy of sciences,nanjing210008,china) chinese Acad Sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Peoples R China

As one of the representative members of the Late Palaeozoic Cathaysian flora,Cathaysiodendron has been previously recorded from the Early Permian Taiyuan and Shanxi Formations in north *** species of Cathaysiodendron presented here are from the lower member of Chouniugou Formation of Ciyao,Jingyuan,*** overlying marine beds yield fusulinids that are of Visean age in western Europe and conodonts of the Datang Stage in south china,so that the age of the bed containing Cathaysiodendron as Visean,Early Carboniferous,is well *** a record of Cathaysiodendron is significant in terms of Carboniferous phyto-geography and the evolution of the Cathaysian Lepidophytes.A new species,Cathaysiodendron jingyuanense Wang&Wu *** described and a second one mentioned.

关键词： Cathaysiodendron Early Carboniferous Visean Cathaysian flora

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Spacial organization on the rural settlements in plain areas—taking Pinghu city in Zhejiang of china as an example

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Journal of Geographical sciences 2000年第3期10卷 59-64页

作者： XUE Dong-qian1, YAO Shi-mou2. ZHANG Hong1 (1. Dept. of Tourism and Environment, Shaanxi Normal University, Xi’an 710062. china 2. nanjing {2. of geography and limnology, chinese academy of sciences, nanjing 210008, china)

This paper analyses the spacial distribution, quantity-scale, function-structure and facilities from the angle of spacial organizational optimizing theory and sustainable development thought. The authors point out the distributional principles of rural settlements in plain areas, and put forward planning and distribution of various levels of rural settlements (central villages, basic villages and natural villages).

关键词： plain area central villages basic villages natural villages spacial organization

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The Urbanization Pattern of china in the 2.st Century

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中国人口·资源与环境：英文版 2005年第2期3卷 55-63页

作者： Wang Chengxin 1,2. Yao Shimou 1 & Wang Gefang 31 nanjing institute of {2. & limnology, the chinese academy of sciences, nanjing 210008, china 2.Graduate School, the chinese academy of Science, Beijing 100039, china 3 Shandong Party School of the Communist Party, Jinan 2.002., china nanjing institute of {2. and limnology Chinese Academy of Sciences Nanjing 210008 China Graduate School Chinese Academy of Science Beijing 100039 China Shandong Party School of the Communist Party Jinan 250021 China

The 2.st century is referred to as a"century for cities" or "era for cities" and china hasalso speeded up its process of urbanization. It is veryimportant to choose a scientific urbanization patternto exert the function of cities and realize our dreamfor china to become a powerful modernized ***’s concluded from history since 1800 that the patternof the world urbanization has transformed from"extensive" to "intensive". However, it is still anextensive pattern in china, and there are manyproblems behind the splendid achievements, reflectedon the urbanization process of our country since1949. Today, sustainable development and theknowledge economy are the themes of the cities; itis inevitable to change our urbanization *** on the dialectic relationship of quality andquantity, the article points out that urbanizationshould not only focus on quantity but also on qualityin china. High quality and multiform urbanizationpattern is an inevitable choice of china, and thedevelopment of the region can also be exalted by theradiation of the cities. But what’s the real meaningof the new pattern? What’s its difference from thewestern countries’? The article discusses its contentaccording to the reality of china.

关键词： Urbanization pattern multiform intensive china

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Effect of climatic change on snowmelt runoffs in mountainous regions of inland rivers in Northwestern china

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Science china Earth sciences 2006年第8期49卷 881-888页

作者： WANG Jian1 & LI Shuo2.1. Cold and Arid Regions Environmental and Engineering Research institute, chinese academy of sciences, Lanzhou 730000,{2. 2. College of geography, nanjing Normal University, nanjing 2.0097,{2. 1. Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou 730000 China 2. College of geography Nanjing Normal University Nanjing 210097 China

Climatic change has significant impacts on snow cover in mid-latitude mountainous re- gions, in the meantime, spatial and temporal changes of snow cover and snowmelt runoffs are con- sidered as sensitive indicators for climatic change. In this study, the upper Heihe Watershed in the Qilian Mountains was selected as a typical area affected by snow cover and snowmelt runoffs in northwestern china. The changes in air temperatures, precipitation, snowfall and spring snowmelt runoffs were analyzed for the period from 1956 to 2.01. The results indicate that climatic warming was apparent, particularly in January and February, but precipitation just fluctuated without a clear trend. The possible changes of snowmelt runoffs in the upper Heihe watershed in response to a warming of 4℃ were simulated using Snowmelt Runoff Model (SRM) based on the degree-day factor algorithm. The results of the simulation indicate that a forward shifting of snow melting season, an increase in water flows in earlier melting season, and a decline in flows in later melting season would occur under a 4℃ warming scenario.

关键词： climatic changes, snowmelt runoff, SRM model, upper Heihe Watershed, simulating.

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