基于卫星测高数据的2002～2018年太湖水位变化监测

针对传统水位监测方法的弊端以及太湖水位变化监测的现实需求,基于Envisat和Cryosat-2测高数据,采用Morlet小波分析、Mann-Kendall检验法研究2002年6月～2018年12月近20a的水位以及周期变化,并应用实测数据进行精度验证,从气象因素和人为影响两方面分析其不同时间尺度的变化趋势以及原因.结...     

洪泽湖湿地生态服务功能分区及其效益分析

总结了洪泽湖湿地的11种生态服务功能,采用生态服务功能相容性分析方法,将洪泽湖湿地生态系统划分为6个功能区:重要物种栖息区、湖体水产养殖区、水产品精养区、水源供应区、社会文化功能区和污染物降解区,并提出了相应的保护措施。     

太湖水体中丁基锡化合物污染现状研究

对太湖表层水、沉积物和水生生物样品的丁基锡污染物进行了研究.结果表明,绝大多数表层水样中未检出丁基锡化合物;沉积物样品中丁基锡的检出率为50%,浓度在0～0.95ng/g范围内,主要以一丁基锡为主;生物样品中检测到较高含量的丁基锡污染物,总丁基锡浓度为27.05～181.23 ng/g,这反映丁基锡具有明显的生物富集效应.生物样品中三丁基锡是主要污染物,大约占总丁基锡含量的70%.太湖中丁基锡的污染来源可能主要来自养殖网箱和船舶防污涂料的使用.     

湖南典型农田土壤有机碳含量及其演变趋势

以湖南省沅江市(28°42′～29°11′N、112°16′～112°56′E)为代表,通过典型样区密集取样分析和同一区域的历史资料比较,研究了洞庭湖区农业用地土壤有机碳的演变趋势,发现稻田土壤有机碳在最近25a中稳步增加,而改为旱地的土壤有机碳含量减少.2004年典型样区土壤有机碳均值为(26.66±4.93)g·kg^-1,主要分布区间为20～35g·kg^-1,比1979提高22.64%;其中耕作制度为双季稻的土壤有机碳含量,由1979年的20.29g·kg^-1提高到了2004年的28.12g·kg^-1,年均增加量约313.5mg·kg^-1(年递增率为1.15%);耕作制度为一季稻的土壤有机碳含量,由1979年的20.29g·kg^-1提高到了2004年的27.25g·kg^-1,年均增加量约278.3mg·kg^-1(年递增率为1.16%),耕作制度为水旱轮作的土壤有机碳含量,由1979年的20.29g·kg^-1提高到了2004年的23.90g·kg^-1,年均增加量约144.5mg·kg^-1(年递增率为0.78%),而改为旱地的土壤有机碳含量,由1979年的20.29 g·kg^-1降低到了2004年的18.40g·kg^-1,年均减少量约75.48mg·kg^-1(年递减率为0.37%).方差分析表明,稻田土壤有机碳的增加达到了极显著水平,改为旱地的土壤有机碳含量的减少未达到了显著水平.表明洞庭湖区不同利用类型的土地均是重要的固碳场所,农业用地的土壤有机碳库是大气CO₂循环的“汇”,而不是“源”.     

太湖梅梁湾沉积物中多环芳烃的生态和健康风险

持久性有机物引起的水质安全性问题日益受到广泛的关注.利用生态和健康风险评价的原理和方法,对太湖梅梁湾水源地沉积物中的多环芳烃可能导致的负面效应进行了分析.首先采用商值法筛选出该地区沉积物中具有潜在风险的多环芳烃,再进一步用建立在暴露浓度分布和物种敏感度分布上的概率法定量表征风险.结果表明,太湖梅梁湾水源地沉积物的多环芳烃中,菲、荧蒽、芘、苯并[a]蒽、屈、苯并[a]芘、二苯并[a,h]蒽7种具有潜在风险;在保护95%的物种水平下,菲的风险最小,而荧蒽和芘风险较高,达20%.健康风险分析表明,美国EPA提出的7种具有遗传毒性的多环芳烃其致癌风险在梅梁湾沉积物中均在10-5水平以下.     

Land-cover changes in an urban lake watershed in a mega-city, Central China

Urbanization can exert a profound influence on land covers and landscape characteristics. In this study, we characterize the impact of urbanization on land cover and lacustrine landscape and their consequences in a large urban lake watershed, Donghu Lake watershed (the largest urban lake in China), Central China, by using Landsat TM satellite images of three periods of 1987, 1993 and 1999 and ground-based information. We grouped the land covers into six categories: water body, vegetable land, forested land, shrub-grass land, open area and urban land, and calculated patch-related landscape indices to analyze the effects of urbanization on landscape features. We overlaid the land cover maps of the three periods to track the land cover change processes. The results indicated that urban land continuously expanded from 9.1% of the total watershed area in 1987, to 19.4% in 1993, and to 29.6% in 1999. The vegetable land increased from 7.0% in 1987, 11.9% in 1993, to 13.9% in 1999 to sustain the demands of vegetable for increased urban population. Concurrently, continuous reduction of other land cover types occurred between 1987 and 1999: water body decreased from 30.4% to 23.8%, and forested land from 33.6% to 24.3%. We found that the expansion of urban land has at least in part caused a decrease in relatively wild habitats, such as urban forest and lake water area. These alterations had resulted in significant negative environmental consequences, including decline of lakes, deterioration of water and air quality, and loss of biodiversity.     

PCB Levels and Trends Within the Detroit River-Western Lake Erie Basin: A Historical Perspective of Ecosystem Monitoring

An international workshop held in the spring of 2002 convened a group of technical experts to address monitoring, modeling, and management of PCBs within the Detroit River-Western Lake Erie basin. Participants shared and discussed a diverse set of research data bases pertaining to PCB levels within the region, discussed observed changes within different components of the local ecosystem, and identified several primary issues impacting future PCB management strategies. Results presented at the workshop indicate dramatic reductions in PCB contamination levels have been observed in much of study area between the late 1970s and mid-1990s. Estimates of loadings attributable to water and atmospheric sources have generally declined, as have PCB concentrations in herring gull eggs, smelt and walleye. Nevertheless, additional improvements have not been observed during recent years and elevated contamination levels remain a concern within local hot spots, particularly in the lower Detroit River and Trenton Channel. A primary recommendation broadly supported by workshop participants is the need to maintain, support, and coordinate a comprehensive ecosystem monitoring program for the Detroit River-Western Lake Erie basin, one that incorporates both near-field and far-field monitoring elements. Such a program is crucial to provide necessary data in support of understanding ecosystem trends, calculating annual mass loadings to the system, assessing impacts of remediation actions, developing improved modeling frameworks, and formulating cost-effective management strategies for the future.     

The Status of Pesticide Residues in the Drinking Water Sources in Meiliangwan Bay, Taihu Lake of China

The study was carried out to assess the levels of pesticide residues in the water of Meiliangwan Bay, Taihu Lake of China. The most commonly employed organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and herbicide atrazine were analyzed. The water samples were collected seasonally from Meiliangwan Bay within a period of one year. The pesticides were analyzed by gas chromatography (GC) with μECD or NPD after solid-phase extraction (SPE), which was confirmed by GC with an ion trap mass spectrometry (MS). The mean concentrations were 1.98 ng/l for lindane, 0.378 ng/l for heptachlor epoxide, 0.367 ng/l for p,p′-DDE, 0.496 ng/l for p,p′-DDD, 1.06 ng/l for p,p′-DDT and 51.6 ng/l for dichlorvos, 39.0 ng/l for demeton, 346 ng/l for dimethoate, 4.12 ng/l for methyl parathion, 11.6 ng/l for malathion, 2.17 ng/l for parathion and 217 ng/l for atrazine. Generally, low concentrations of OCP were found, whereas the concentrations of the OPPs and atrazine in the water of Taihu Lake were relatively high. Heptachlor epoxide and lindane were the two most commonly encountered OCPs while dichlorvos, demeton and dimethoate were found to have much higher concentrations and occurrences than other OPPs.     

稀土元素对富营养化水体中藻类增长的影响

利用藻类生长潜力测试方法,在太湖五里湖区水样中分别添加不同浓度轻,中、重３种稀土元素、Ｇｄ（Ⅲ）、Ｙ（Ⅲ）与３种稀土混合物,研究稀土元素对富营养化水体中藻类增长的影响。     

城市河流与湖库中痕量有机污染物的研究

通过采用ＧＤＸ－５０２富集,ＧＣ－ＭＳ分析,对城市河流、湖库中的痕量有机污染物进行分析,共检出５８种有机污染物,其中含有多种美国ＥＰＡ公布的重点污染物,从而为痕量有机污染物的研究建立了灵敏度高,分辨率好的测试方法。