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MONITORING OF HEAVY METALS IN MACROPHYTES AND ASSESSMENT OF LACUSTRINE ENVIRONMENTAL QUALITY OF TAIHU LAKE
水生高等植物对太湖重金属的监测及其评价

Dai Quanyu,
戴全裕

环境科学学报 , 1983,
Abstract: Taihu Lake is one of the five famous big fresh-water lakes in China with an area of 2460km2 and a depth of about 2-3m. In order to assess the lacustrine environmental quality of Taihu Lake heavy metals in macrophytes were investigated in the year between 1980-1981. The monitoring data and in turn assessment of the lacustrine environmental quality of Taihu Lake were studied and came to following conclusions:1) The heavy metals in macrophytes in polluted area are found to be higher than in non-polluted area.2) The heavy metals in macrophytes at the mouth of the river are higher than in other lacustrine places.3) The higher the heavy metals in natural lacustrine soils, the higher are the heavy metals in macrophytes in this same area.It is shown that macrophytes possess the capability of indicating heavy metal elements in the Lake. Taihu Lake so far has been found of good water quality, with only 1% of it polluted by heavy metals.
Spatial distribution and stratigraphic characteristics of surface sediments in Taihu Lake, China
Ji Shen,HeZhong Yuan,EnFeng Liu,JianJun Wang,Yong Wang
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-010-4214-0
Abstract: A geophysical survey was carried out for Taihu Lake, one of the largest shallow lakes in China. The StrataBox Marine Geophysical Instrument was applied for the first time to obtain high-resolution seismic data (in the form of vectorgraphs) of the lake sediment. Data were then interpreted by SonarWiz.Map acoustics software. Data were correlated with core stratigraphy from the lake as well as an outcrop on the northern side of the lake at Yao Bay. Results show that the upper 10 m sediment (beneath the interface of the sediment and the overlying lake water) is characterized by laminated sediments, which can be classified into two stratal types, i.e. lacustrine sediment stratum (U1) and underlying hard loess stratum (U2). The contact of these two lithologies is not continuous, and part of it is absent in the lake basin. Unequally spread over the lake basin, the lacustrine sediment (mainly consisting of sludge and muddy-clay) is found in areas along the western bank, to the northwest of the Xishan Mountains and along the northwestern side of the lake. In the rest of the lake basin, the hard loess stratum is exposed in outcrops. The depth of the lacustrine sediment ranges from 1 to 2 m, while the depth of the sludge (closely related to the modern lacustrine environment) varies from 0.03 to 1.0 m. The spatial distribution of lacustrine sediments in Taihu Lake is primarily influenced by transportation and sedimentation of riverine materials, as well as the hydrodynamics of lake currents.
CHANGES IN ECO-ENVIRONMENT AND CAUSES FOR LAKE TAIHU, CHINA
太湖生态环境演化及其原因分析

秦伯强,罗潋葱
第四纪研究 , 2004,
Abstract: Lake Taihu located in the Changjiang River Delta, has been characterized by its shallowness with a water surface area of 2 338km 2 and a mean depth of 1.9m. Its flat topographic catchment made the complexity of hydraulic connection between the rivers and the lake. The major runoff comes from mountainous west and southwest of watershed of Lake Taihu, and flows out throughout East Taihu Bay and the River Wangyu in northeast which flush into Huangpu River and Changjiang River. This causes shorter water retention in the south of lake than that in the north. In the past decades, eutrophication problem gradually became serious with a large amount of pollutants from Wuxi City and Changzhou City discharged into Wuli Bay and Mailiang Bay in the north of Lake Taihu. The water quality, therefore, is much worse in the north than that in the south of the lake. Aquaculture in East Taihu led to water quality deterioration and eutrophication, which caused the problem of water supply in the surrounding areas. In addition, the function of East Taihu for flood discharge resulted in the increase in sedimentation rate and made this area toward marsh. Reclaimation around the lake due to development of agriculture production and construction of water conservancy facilities over the rivers resulted in the reduction of pollutant retention ability. Solutions for these problems need an enhanced management based on the understanding of the changes in the lake eco system.
Lacustrine wetland in an agricultural catchment: nitrogen removal and related biogeochemical processes
R. Balestrini, C. Arese,C. Delconte
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2008,
Abstract: The role of specific catchment areas, such as the soil-river or lake interfaces, in removing or buffering the flux of N from terrestrial to aquatic ecosystems is globally recognized but the extreme variability of microbiological and hydrological processes make it difficult to predict the extent to which different wetlands function as buffer systems. In this paper we evaluate the degree to which biogeochemical processes in a lacustrine wetland are responsible for the nitrate removal from ground waters feeding Candia Lake (Northern Italy). A transect of 18 piezometers was installed perpendicular to the shoreline, in a sub-unit formed by 80 m of poplar plantation, close to a crop field and 30 m of reed swamp. The chemical analysis revealed a drastic NO3–-N ground water depletion from the crop field to the lake, with concentrations decreasing from 15–18 mg N/l to the detection limit within the reeds. Patterns of Cl–, SO42–, O2, NO2–-N, HCO3– and DOC suggest that the metabolic activity of bacterial communities, based on the differential use of electron donors and acceptors in redox reactions is the key function of this system. The significant inverse relationship found between NO3–-N and HCO3– is a valuable indicator of the denitrification activity. The pluviometric regime, the temperature, the organic carbon availability and the hydrogeomorphic properties are the main environmental factors affecting the N transformations in the studied lacustrine ecosystem.
Lacustrine wetland in an agricultural catchment: nitrogen removal and related biogeochemical processes
R. Balestrini,C. Arese,C. Delconte
Hydrology and Earth System Sciences Discussions , 2007,
Abstract: The role of specific catchment areas, such as the soil-river or lake interfaces, in removing or buffering the flux of N from terrestrial to aquatic ecosystems is globally recognized but the extreme variability of microbiological and hydrological processes make it difficult to predict the extent to which different wetlands function as buffer systems. In this paper we evaluate the degree to which biogeochemical processes in a lacustrine wetland are responsible for the nitrate removal from ground waters feeding Candia Lake (Northern Italy). A transect of 18 piezometers was installed perpendicular to the shoreline, in a sub-unit formed by 80 m of poplar plantation, close to a crop field and 30 m of reed swamp. The chemical analysis revealed a drastic NO3-N ground water depletion from the crop field to the lake, with concentrations decreasing from 15–18 mg N/l to the detection limit within the reeds. Patterns of Cl, SO4, O2, NO2-N, HCO3 and DOC suggest that the metabolic activity of bacterial communities, based on the differential use of electron donors and acceptors in redox reactions is the key function of this system. The significant inverse relationship found between NO3-N and HCO3 is a valuable indicator of the denitrification activity. The pluviometric regime, the temperature, the organic carbon availability and the hydrogeomorphic properties are the main environmental factors affecting the N transformations in the studied lacustrine ecosystem.
Detection of Critical LUCC Indices and Sensitive Watershed Regions Related to Lake Algal Blooms: A Case Study of Taihu Lake  [PDF]
Chen Lin,Ronghua Ma,Zhihu Su,Qing Zhu
International Journal of Environmental Research and Public Health , 2015, DOI: 10.3390/ijerph120201629
Abstract: Taihu Lake in China has suffered from severe eutrophication over the past 20 years which is partly due to significant land use/cover change (LUCC). There is an increasing need to detect the critical watershed region that significantly affects lake water degradation, which has great significance for environmental protection. However, previous studies have obtained conflicting results because of non–uniform lake indicators and inadequate time periods. To identify the sensitive LUCC indices and buffer distance regions, three lake divisions (Meiliang Lake, Zhushan Lake and Western Coastal region) and their watershed region within the Taihu Lake basin were chosen as study sites, the algal area was used as a uniform?lake quality indicator and modeled with LUCC indices over the whole time series. Results showed that wetland (WL) and landscape index such as Shannon diversity index (SHDI) appeared to be sensitive LUCC indices when the buffer distance was less than 5 km, while agricultural land (AL) and landscape fragmentation ( Ci) gradually became sensitive indices as buffer distances increased to more than 5 km. For the relationship between LUCC and lake algal area, LUCC of the WC region seems to have no significant effect on lake water quality. Conversely, LUCC within ML and ZS region influenced algal area of corresponding lake divisions greatly, while the most sensitive regions were found in 3 km to 5 km, rather than the whole catchment. These results will be beneficial for the further understanding of the relationship between LUCC and lake water quality, and will provide a practical basis for the identification of critical regions for lake.
Lake Sediment Records on Climate Change and Human Activities in the Xingyun Lake Catchment, SW China  [PDF]
Wenxiang Zhang, Qingzhong Ming, Zhengtao Shi, Guangjie Chen, Jie Niu, Guoliang Lei, Fengqin Chang, Hucai Zhang
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0102167
Abstract: Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS) and CaCO3 content), as well as accelerator mass spectrometry (AMS) 14C datings, four major climatic stages during the Holocene have been identified in Xingyun′s catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60–1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (~1.35 cal. ka BP) were associated with the ancient Dian culture within Xingyun’s catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.
Sediment resuspension in the Lake Taihu, China
Chunhua Hu,Weiping Hu,Fabing Zhang,Zhixin Hu,Xianghua Li,Yonggen Chen
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-0731-2
Abstract: In order to examine the intensity of surficial sediment resuspension in Lake Taihu, a large shallow lake in eastern China, suspended sediment concentrations (SSCs) were measured on the basis of analysis of water samples collected using an innovative multi-level water sampler. The results show that under calm weather conditions, the SSC is relatively homogenous through the entire water column. However, when strong winds occur, the SSC in the bottom layer is 1–2 orders of magnitude greater than in the surface layer; thus, in this case, the amount of total suspended matter in the water column cannot be estimated using the SSC values of the surface layer alone. Furthermore, the depth of disturbance, or the thickness of the sediment layer that is set in motion by wind-wave induced currents, is of the order of 100 mm.
Sediment resuspension in the Lake Taihu, China
Chunhua Hu,Weiping Hu,Fabing Zhang,Zhixin Hu,Xianghua Li,Yonggen Chen,
HU
,Chunhua,HU,Weiping,ZHANG,Fabing,HU,Zhixin,LI,Xianghua,CHEN,Yonggen

科学通报(英文版) , 2006,
Abstract: In order to examine the intensity of surfi-cial sediment resuspension in Lake Taihu, a large shallow lake in eastern China, suspended sediment concentrations (SSCs) were measured on the basis of analysis of water samples collected using an in-novative multi-level water sampler. The results show that under calm weather conditions, the SSC is rela-tively homogenous through the entire water column. However, when strong winds occur, the SSC in the bottom layer is 1-2 orders of magnitude greater than in the surface layer; thus, in this case, the amount of total suspended matter in the water column cannot be estimated using the SSC values of the surface layer alone. Furthermore, the depth of disturbance, or the thickness of the sediment layer that is set in mo-tion by wind-wave induced currents, is of the order of 100 mm.
Characteristics of petroleum contaminants and their distribution in Lake Taihu, China
Jixiang Guo, Jia Fang, Jingjing Cao
Chemistry Central Journal , 2012, DOI: 10.1186/1752-153x-6-92
Abstract: The result showed that water samples from near industrial locations were of relatively higher petroleum contaminants concentrations. The oil pollutants concentrations in different areas of Lake Taihu ranged from 0.106 mg/L to 1.168 mg/L, and the sequence of total contents distribution characteristics of petroleum pollutants from high to low in different regions of Taihu Lake was: “Dapu”, “Xiaomeikou”, “Zhushan Bay”, “Lake center”, “Qidu”. The results showed that total concentrations of n-alkanes and PAHs ranged from 0.045 to 0.281 mg/L and from 0.011 to 0.034 mg/L respectively. In the same region, the concentrations of hydrocarbon pollutants in the surface and bottom of the lake were higher than that in the middle.This paper reached a conclusion that the petroleum contaminants in Taihu Lake mainly derived from petroleum pollution caused by human activities as indicated by OEP, bimodal distribution, CPI, Pr/Ph ratio, the LMW/HMW ratio and other evaluation indices for sources of n-alkanes and polycyclic aromatic hydrocarbons (PAHs).Taihu Lake is one of the five largest freshwater lakes in China, and it is a typical plain eutrophic shallow lake. As the major fresh water resource in the economically developed region of Yangtze River Delta, the water quality and environmental condition of Taihu Lake have direct influence on the natural environment and sustainable development of economy in this region [1]. With rapidly economic development of the lake area, the petroleum products and oil wastewater produced in the process of oil processing, transportation and application of various refined oil have been inevitably discharged into Taihu Lake.Petroleum is a complex mixture mainly composed of hydrocarbons, in which most of alkanes are proved to be narcotic and irritant, and most of PAHs have strong toxicity, carcinogenicity, teratogenicity and mutagenicity [2,3]. The large amount of oil pollutants in water environment will cause serious pollution to the water ecosystems and
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