杭嘉湖南排工程调水试验对水质改善的效果分析

在确保杭嘉湖平原区域防洪安全和供水安全的前提下,对导流港东大堤沿线各闸、太浦闸和南排各闸组合调度,通过对两次南排调水试验的效果进行监测和分析,结果表明:该措施可有效配合太湖流域"引江济太"工程,进一步增加杭嘉湖地区"引江济太"水量,扩大平原水体流动范围,增加水体流速,提高水环境容量.该研究成果可为太湖流域类似地区的工程...     

海菜花花粉母细胞微核技术监测滇池水质污染状况

以海菜花生长环境水(路南长湖水)处理作阴性对照,以滇池5个样点的水样处理作阳性对照,利用海菜花花粉母细胞微核技术监测评价滇池水质污染物致突变的情况,测定各采样点水样的海菜花花粉母细胞微核千分率及污染指数.结果表明:滇池5个样点的水样均使海菜花花粉母细胞微核千分率急剧增加,用海莱花水生植物建立的水体环境污染检验系统,可避...     

三次样条插值方法在太湖水质评价中的应用

采用三次样条插值方法对全太湖代表性水质指标和反映富营养化、藻类密度的指标进行线性插值,绘制太湖主要水质指标浓度空间变化图,直观反映了太湖水质总体状况和空间分布特征,较好地解决了监测站点密度不够的问题。虽然评价结果在水质变化较大的局部湖区存在一定误差,但该方法对于大面积湖泊水质评价工作具有借鉴价值。     

淀山湖水污染状况分析与综合治理对策研究

根据淀山湖湖区和入湖河流2000—2009年水质监测资料,分析淀山湖及环湖河流近期水质变化趋势;从城市污水排放、工业污染及农业面源等方面研究淀山湖污染特性,分析淀山湖水资源保护形势;兼顾开发、利用、保护要求,统筹上游与下游,提出淀山湖污染源治理、水利工程调水引流、污染物排放总量控制与断面浓度控制相结合的污染控制制度,建立环湖协商机制等综合治理对策。     

环太湖出入湖水量影响因素分析及对策措施研究

在收集整理1986—2007年环太湖河道出入湖水量实测资料的基础上,利用面积包围法及相关法,以太湖流域水资源四级分区为统计单元对环太湖出入湖水量进行计算分析。结果表明:降雨、水资源调度及太湖直接取水户取水量变化为影响出入湖水量变化的主要因素。建议水行政相关部门建立健全水资源监控系统,并加快制定和实施太湖水量分配方案,加强取水许可监督工作。     

查干湖水体溶解氧浓度的变化趋势及影响因素分析

通过多年对查干湖水质的监测以及近几年逐月监测参数,综合分析水体溶解氧变化趋势和驱动机制,总结出导致溶解氧浓度降低的原因,除了光合作用影响外,溶解氧浓度较低的补给潜水、水体中存在的还原性物质也是主要因素。提出将潜水变为地表水、增加对水体中还原性物质的转化能力等增加溶解氧的措施。     

Spatio-temporal variability of diatom assemblages in surface sediments of Lake Peipsi

The modern diatom assemblages in surface sediments of large and shallow Lake Peipsi sensu stricto (2611 km²; maximum depth 12.9 m) in north-eastern Europe (Estonia) were studied. Ordination techniques were used to identify physical environmental parameters (grain size of sediment, water depth and distance from the shore) that explain the distribution of diatoms in the lake. Diatom species distribution and concentration in surface sediment showed large variations (concentrations varied from 3.3 × 10⁶ to 149 × 10⁶ g⁻¹ dry weight). The texture of surface sediments and concentration of diatoms are highly correlated (p ≤ 0.05), thus suggesting that the relocation of cohesive particles (silt) due to wind and wave actions affects the spatial variations of diatoms in surface sediments. The diatom data set analysed in the 1970s, and samples taken in 2006 showed some perceptible changes in the composition and concentrations of the diatom assemblages over this time period. However, main dominant diatom taxa have not changed during more than 25 years.     

Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth

A thermophilic anaerobic bacterium was isolated from a sublacustrine hydrothermal vent site in Lake Tanganyika (East Africa) with recorded fluid temperatures of 66-103 °C and pH values of 7.7-8.9. The bacterium (strain TR10) was rod-shaped, about 1 by 5 μm in size, and readily formed distal endospores. Based on the 16 S rDNA sequence the novel strain was homologous to Thermobrachium celere and Caloramator indicus, which are closely related. The novel strain was strictly anaerobic, fermentative and had a doubling time as short as 10 min during growth on complex substrates, such as yeast extract and peptone. The optimum temperature for growth was 60 °C, while minimum and maximum temperatures were 40 and 75 °C. The pH response was alkalitolerant with optimum pH at 7.4 and 8.5 depending on the growth medium. The distinct feature of rapid proliferation and endospore formation may allow the novel organism to exploit the temporarily fluctuating growth conditions in the hydrothermal vent environments of Lake Tanganyika.     

Unionid mussels from nearshore zones of Lake Erie

Concern exists that the introduction of dreissenid mussels following long-term effects of pollution may have completely eliminated native mussel species from Lake Erie. Natural seiche events were used to facilitate surveys for live unionids on five occasions in the western basin of Lake Erie and Sandusky Bay between 2007 and 2009, and beach and estuary surveys were conducted at numerous additional sites between 2004 and 2009. Sixteen unionid species were found living in or near Lake Erie, including six sites in the nearshore zone of the lake. Each community consisted of live individuals from two to eight species, and evidence included live and/or fresh dead material from several state listed species at multiple sites. Where estimated, the mean overall density was low at 0.09 unionids/m², although similar to other known unionid refuges in the lower Great Lakes. While the ephemeral nature of seiche events makes them a limited survey tool, their application combined with increasing numbers of fresh shells washing ashore over the past few years indicates that unionids are extant in the western basin of Lake Erie, and may further suggest that conditions may be improving for native mussel species.     

Assessment of landed and non-landed by-catch of walleye, yellow perch and white perch from the commercial gillnet fisheries of Lake Erie, 1994-2007

Theoretical by-catch (including landed and non-landed bycatch) of walleye (S. vitreus), yellow perch (Perca flavescens), and white perch (Morone americana) from the Lake Erie commercial gillnet fisheries during 1994-2007, was predicted by a delta model developed on the fishery-independent survey data (Lake Erie Partnership Index Fishing Survey). The delta model consisted of one generalized additive model and one AdaBoost model. The generalized additive model was used to predict non-zero catches of the by-catch species, and the AdaBoost model was used to predict the probability of obtaining non-zero catches. Non-landed by-catch was estimated as the difference between the theoretical by-catch predicted from the delta model and the landed by-catch recorded in the commercial fishery data. The theoretical by-catch of walleye was relatively higher in the west basin in October. A higher theoretical by-catch of yellow perch occurred in the west central basin in November, and a higher theoretical by-catch of white perch occurred in the west central basin in October. We observed higher levels of non-landed by-catch of walleye in the west basin during August to September, higher levels of non-landed by-catch of yellow perch in the west central and east central basins in November, and higher levels of non-landed by-catch of white perch in the west basin in August and November. The combination of the AdaBoost model with the delta model provided an alternative model in by-catch analyses when the percentage of zero observations was high.