Spatial Heterogeneity of Cyanobacteria and Diatoms in a Thermally Stratified Canyon‐Shaped Reservoir

Phytoplankton communities in lakes and reservoirs are seldom homogeneously distributed but usually aggregate in patches and gradients. In this study we have combined the use of in vivo spectrofluorometry and acoustic Doppler current profiling to investigate the effect of water movements on the spatial distribution of cyanobacteria and diatoms in a thermally stratified reservoir in SW Spain. The distinctive canyon‐shaped morphometry of the reservoir (El Gergal) favoured the development of a “conveyor belt” pattern of circulation aligned with the long axis of the reservoir. Under non‐regulated conditions, the spatial distribution of phytoplankton was almost entirely dependent on the interactions between advective transport and the buoyancy properties of the different functional groups of phytoplankton. The positively‐buoyant cyanobacteria accumulated near the surface and were then transported downwind by the surface drift currents. In contrast, the negatively‐buoyant diatoms sank in the water column and were transported upwind by the sub‐surface return currents. When deep water was abstracted from the reservoir, these distribution patterns were modified. The results are discussed in relation to the problem of acquiring representative water samples from the reservoir and the application of a simple empirical model to optimize the location of the station used for routine cyanobacteria sampling on the reservoir. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

南宁市湖库型饮用水源景观结构与涵养功能关系耦合优化

为探明湖库型饮用水源景观结构与涵养功能间的内在机理,优化水源涵养林功能,保护水源安全,借助遥感解译技术得到各用地类型面积并计算水源涵养功能指数,依据取水量和水源涵养量间水量平衡模式计算所需最小森林面积,应用多元数量分析方法探究水源涵养功能指数、景观格局指数、水质指标之间的耦合关系。结果表明:(1)水源地3 km缓冲区较500 m缓冲区的水源涵养功能有所下降。(2)用最小面积法优化筛选出以软阔叶林、栎林、硬阔叶林、竹林为主的岸边带森林生态系统可有效提高水源涵养功能,最大限度的满足饮用水源保护区面积、集雨区面积和涵养区面积间的数量关系。(3)水源涵养功能与景观格局、水资源、水质和污染物排放间可建立起通过显著性检验的多元回归拟合模型方程。(4)多维尺度综合分析过程可诊断出南宁市湖库型饮用水源在生态系统稳定性、水资源量和水质方面存在的生态安全与风险隐患问题,建议南宁市开展饮用水源环境综合整治、生态系统保护与修复工作。     

土地利用变化对生态系统服务功能的影响——以密云水库流域为例

生态系统服务功能与人类福利息息相关,土地利用变化是生态系统服务功能退化的主要驱动力之一,以人地关系紧张,生态系统服务功能变化剧烈的密云水库流域为对象,分析流域1990-2009年土地利用的变化,采用空间显式的生态系统服务功能评估软件InVEST中的“产水量”、“土壤保持”、“水质净化”模型,研究流域土地利用变化对生态系统服务功能的影响.结果表明1990-2009年密云水库流域土地利用变化剧烈,农田、草地和水体的面积分别减少了30％、48％、61％,林地、建筑用地和裸地的面积增加,增幅分别为30％、230％、282％.随着土地利用变化,生态系统服务功能相应产生着显著变化,研究期内,土壤保持功能和固碳服务分别增加46％和19％,但水资源供给服务和水质净化功能分别减少了3％和25％.农田面积的减少和森林的扩张改善了土壤保持服务,森林面积的增加同时也改善了固碳服务,但会削弱水资源供给服务,建筑用地的扩张会大幅度削弱水质净化功能,为维持和改善流域整体的生态系统服务功能,应加强对森林和建筑用地的控制.其研究为密云水库流域土地利用科学管理决策提供参考.     

不同尺度景观空间分异特征对水体质量的影响——以深圳市西丽水库流域为例

由于景观格局对水体质量的影响是依赖于研究尺度、并且随着时间尺度和空间尺度的变化而变化的,因此探讨不同尺度上景观格局变化对水质的影响程度具有重要的研究价值。从深圳市水库流域水环境保护的需求出发,选择西丽水库及其汇水子流域为研究对象,以陈利顶等提出的景观空间负荷对比指数分析方法为基础,区分高度、坡度和距离3个空间要素计算了分区和累积景观空间负荷对比指数,继而利用该指数对比分析了不同时空尺度上“源”“汇”景观空间分异特征变化对水质的影响程度。研究结果表明,不同尺度上的景观空间分异特征可以显著影响“源”“汇”景观在非点源污染输出和削减方面贡献程度的对比关系,从而影响水体质量。由于不同尺度上景观空间分异特征的复杂性以及“源”“汇”景观在数量和类型方面差异的显著性,景观空间负荷对比指数的对比关系并不能良好地反映不同空间尺度上景观空间分异特征对水质影响的差异状况,因此必须 针对不同的研究尺度有选择的应用该方法来探讨景观空间分异特征对水质的影响程度。     

Operation of the Kis-Balaton reservoir: evaluation of nutrient removal rates

As one of the major measures for controlling the man-made eutrophication of Lake Balaton, the Hidvég reservoir of 20 km² surface area was built near the mouth of River Zala, draining half the watershed of the lake, and representing the largest nutrient source for the lake. The reservoir, as the first element of the expected total system of 70 km² surface area (Kis-Balaton Control System), started to operate in June 1985, aiming at removing nutrients primarily through sedimentation, adsorption and uptake by macrophytes.Detailed investigations began with the operation. These cover the observation of upstream and downstream nutrient loads and the water quality in the reservoir, the study of major phosphorus removal processes, and analysis of the nitrogen cycle and of the behaviour of phytoplankton, zooplankton, fish and macrophytes. The research programme is completed by the evaluation of observations (including the use of phosphorus budget models), with special emphasis on future operation modes of the reservoir.The nutrient removal efficiencies in the reservoir came up to expectations. The removal rates for suspended solids, total-P, soluble reactive-P and nitrate-N exceeded 50 % in the first full year of operation (1986). As a result of reservoir operation, nutrient loads in the western basin of Lake Balaton have been significantly reduced. However, the improvement in water quality can be expected only with a lag time due to the internal P load of the basin.     

Potential sites of geosmin production by streptomycetes in and around reservoirs

Water from several oligotrophic reservoirs of the North West Water Authority at Longridge, Lancashire, supported only sparse growth of streptomycetes isolated from the reservoirs. Growth was enhanced by nutrient-amendment of the water and one common isolate, identified as Streptomyces albidoflavus , produced geosmin in water which was supplemented with sufficient concentrations of available carbon, nitrogen and phosphorus. The minimum concentrations required for geosmin production were higher than those recorded in natural reservoir water. Synthesis of geosmin in water also required a minimum temperature of about 15dEC. Sterilized samples of reservoir sediment, sediment extract, plant debris from banks and surrounding soil also supported geosmin production by S. albidoflavus. Both bank debris and exposed sediment developed earthy odours without inoculation. The structure of reservoir banks influenced the quantity of plant growth and accumulation of litter, and therefore also the potential for contamination of reservoir water by geosmin. The potential of these various sites of geosmin production to contaminate reservoir water is assessed.     

赣江流域土地利用方式对河流水质的影响

赣江是鄱阳湖的最大支流,是鄱阳湖水污染物的主要来源,查明流域土地利用方式对赣江水质的影响和鄱阳湖的水环境保护具有重要意义。基于2012年对赣江7个主要支流NH+4-N、TP、CODMn和DO浓度的每月测定结果,通过不同空间尺度和土地类型等级划分,利用相关分析和冗余分析研究土地利用方式对赣江流域河流水质的影响。研究结果表明,子流域的土地利用方式对TP的影响大于缓冲区;对CODMn的影响在丰水期大于缓冲区,在枯水期小于缓冲区;对NH+4-N的影响在丰水期与缓冲区接近,在枯水期小于缓冲区;DO受土地利用方式的影响较小。水田中的丘陵水田是赣江水体TP和丰水期CODMn的主要来源;平原水田是枯水期CODMn的主要来源。居民建设用地中的城镇用地是赣江水体TP、NH+4-N和丰水期CODMn的主要来源,农村用地是CODMn的主要来源。水域中的水库坑塘是赣江水体TP和丰水期NH+4-N、CODMn的主要来源。     

我国饮用水源水库微生物多样性研究述评

水源水库的水环境质量和生态安全世人瞩目,微生物在饮用水源水库生态系统的物质循环、能量流动和信息联系中发挥着重要作用,同时其丰度和多样性也是水环境质量监测的重要指标。综述了我国饮用水源水库微生物的作用、丰度、多样性等研究概况,并对水源水库微生物监测方法、蓝细菌分类和毒素特点及未来研究方向进行了讨论。     

层次分析法对南水北调中线水源区的水质评价

层次分析法(AHP)是一种多指标多因素综合评价法,其理论内容深刻而表现形式简单,包括递阶层次结构模型、判断矩阵的建立及其求值、一致性检验和综合指数计算等运算过程.在南水北调中线水源区3个采样点进行了2a的水体浮游植物和9项理化指标的检测,并应用层次分析法通过季节4因素和6项理化指标对水质进行综合评价.结果表明:层次分析综合指数PI在3采样点有差异并且变化灵敏,渠首 (陶岔S1 ) PI=0.5697,水质属于污染;库心 (小太平洋S2 ) PI=0.3619,水质属于尚清洁;丹江入库上游 (大石桥S3 ), PI=0.7755,水质属于中污染;AHP分析结果与实际基本相符.根据结果分析认为:层次分析法做为综合评价法对水质评价有重要性,值得推广应用;丹江口水库是重要的水资源,但目前水质状况并不理想,因此做好水源区的长期生态监测,加强理论和技术研究,改善水质,极为重要.     

水库生态系统特征研究及其在水库水质管理中的应用

水库是一种半人工半自然水体,兴建水库是人类调节自然水资源在时间和空间上分布的主要手段,水库生态系统受人类调节明显,具有独特的生态学特征,对近20a来国际水库生态系统的研究进行总结,概括水库生态系统的主要特征,阐述这些特征在水库中水质管理中的应用与实施方法,强调开展水库生态学研究在我国水资源可持续利用中的重要性和必要性。     

上海中心城区绿地土壤水库特征

以上海中心城区典型公园和公共绿地土壤为研究对象,通过实地调查,分析上海中心城区绿地土壤水库库容、常数特征及影响因子.结果表明: 上海中心城区绿地土壤总库容偏低,但就整个中心城区绿地,土壤蓄积水量可观,达1.88×10⁷ m³;土壤水分现存量较高,占总库容的75.7%,土壤剩余蓄水空间偏低;绿地土壤滞洪库容和有效库容分别占土壤总库容的31.6%和27.2%;而土壤死库容占总库容的44.5%.不同植被类型土壤水库存在差异:其中,乔木和灌木地土壤总库容、剩余蓄水空间均显著高于草地;灌木地土壤滞洪库容、有效库容均显著高于乔木地、草地;但各植被类型土壤水分现存量、死库容差异不显著.建议通过降低土壤压实、增加土壤有机质含量、改善土壤物理性质和优化绿地植物配置来提高城市绿地土壤水库库容.     

The application of the algicide CA 350 in the Lubi Reservoir near Třebič, Czechoslovakia

Summary In 1964 two applications of the algicide CA 350 were made on the reservoir Lubí near Tebí in order to remove a blue-green algae water blooming.The first use of the algicide was made in May. Blue-green algae disappeared during 24 hours and no marked changes occurred of other biological and chemical characteristics in the reservoir water. Two weeks following the control heavy development of green algae was noted to occur in the reservoir, but it ceased in a short interval having no bad effects on the raw water quality.In the beginning of July, about 6 weeks following the first application, Hydrodictyon reticulatum, a green alga, developed in the lower part of the reservoir in such an amount that it must be removed mechanically. This development was probably raised by the deteriorated water quality in the inflowing stream and due to the omission of the suggested preventive measures.Another water bloom appeared in the beginning of August and the algicide was applied again with similar effects.This report confirms the results gained by the workers of the Institute of Hygiene, Prague, on the Sedlice reservoir, and by VEC, who experimented on the Fryták reservoir in 1959: The algicide CA 350 acts immediately against blue-green algae without any side toxic effects produced by copper.     

The application of artificial neural networks to the problem of reservoir classification and land use determination on the basis of water sediment composition

Presented work reports on the use of artificial neural networks to recognize and classify water reservoir types (lakes, rivers) and the nature of their surroundings (forests, fields, meadows) based on the chemical composition of sediments. The quantitative content of a selection of elements (Ag, As, Ba Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, P, Pb, S, Sr, TOC – Total Organic Cabon, V and Zn) in the sediments of lakes and rivers in the Lublin Province (Poland) were taken and used as working data file. Statistical analysis suggested that both reservoir types and area usage differ in terms of the quantity of studied determinants (elements) and thus might be distinguished on their basis. Artificial neural networks were then examined with respect to their ability to recognize and classify the data. Multilayer perceptron was used as the statistical model. Constructed models were able to give correct answers in 74% of cases when classifying reservoir’s area usage and 100% for the type of body of water.     

Air bells of water spiders are an extended phenotype modified in response to gas composition

The water spider Argyroneta aquatica (Clerck) is the only spider that spends its whole life under water. Water spiders keep an air bubble around their body for breathing and build under-water air bells, which they use for shelter and raising offspring, digesting and consuming prey, moulting, depositing eggs and sperm, and copulating. It is unclear whether these bells are an important oxygen reservoir for breathing under water, or whether they serve mainly to create water-free space for feeding and reproduction. In this study, we manipulated the composition of the gas inside the bell of female water spiders to test whether they monitor the quality of this gas, and replenish oxygen if required. We exchanged the entire gas in the bell either with pure O2, pure CO2, or with ambient air as control, and monitored behavioural responses. The test spiders surfaced and replenished air more often in the CO2 treatment than in the O2 treatment, and they increased bell building behaviour. In addition to active oxygen regulation, they monitored and adjusted the bells by adding silk. These results show that water spiders use the air bell as an oxygen reservoir, and that it functions as an external lung, which renders it essential for living under water permanently. A. aquatica is the only animal that collects, transports, and stores air, and monitors its property for breathing, which is an adaptive response of a terrestrial animal to the colonization of an aquatic habitat.     

The study of the multifactorial anthropogenic effect on the ecosystems of the industrial reservoirs of "Maiak" industrial complex

The analysis of the ecological situation of the Southern Urals industrial water reservoirs of the nuclear fuel cycle enterprise, "Mayak" PA is represented. The study was held in the 80s - early 90s. The subjects of the study were: a cooling water reservoir--Kysyl-Tash Lake (R-2) as well as a radioactive waste storage reservoir (R-10). Irtyash Lake, which is a drinking water reservoir for the city of Ozyorsk and Alabuga and Kazhakul Lakes, located on the boundary of the Eastern Urals Radioactive Trace (EURT), were taken as control ones. Such water reservoirs as Irtyash, Kysyl-Tash and the waste storage reservoir (R-10) are incorporated into the Techa River basin; while Alabuga and Kazhakul Lakes are related to the interfluve between the Techa River and the Sinara River. The complex effect from such man--caused factors as radiation, chemical and thermal to water reservoirs' ecosystems was studied. Radionuclide specific activities of the major reservoir components (water, bottom sediments, and biological objects), cumulative stock and radiation doses to the biota were determined. Assessment of the condition of biological structures of individual reservoirs was performed. It was found that the long-term complex influence of radiation, thermal and chemical factors resulted in the formation of the unique technology-induced ecosystems being a part of "Mayak" PA process cycle. Radiation doses to the fish of the cooling water reservoir and the radioactive waste storage reservoir were experimentally estimated. These doses from the incorporated beta-emitters were not less then 2-3 Gy/year. The long-term complex influence of radiation and chemical factors didn't cause any irreversible changes either in the fish population or in the ecosystem. Water purity indicators like crayfish (Astacus leptodactilus Esch) and mollusk (Anodonta cygnea L.) were found in the cooling water reservoir. The comparative analysis of the ecological situation of the reservoirs carried out on the basis of several qualitative indicators and with the help of the formalized scoring system allowed determining that the optimum ecological conditions can be observed in Irtyash Lake. The quality of the environment of Alabuga Lake is slightly lower. The ecological conditions in Kysyl-Tash Lake are up to the standard, while in Kazhakul Lake they are lower than the standard. This is the result of the natural salinization of the ecosystem. The lowest indicator was obtained for the radioactive waste storage reservoir.     

Growth of legionella and other heterotrophic bacteria in a circulating cooling water system exposed to ultraviolet irradiation

The effect of ultraviolet irradiation on the growth and occurrence of legionella and other heterotrophic bacteria in a circulating cooling water system was studied. Water of the reservoir was circulated once in 28 h through a side-stream open channel u.v. radiator consisting of two lamps. Viable counts of legionellas and heterotrophic bacteria in water immediately after the u.v. treatment were 0—12 and 0·7—1·2% of those in the reservoir, respectively. U.v. irradiation increased the concentration of easily assimilable organic carbon. In the u.v. irradiated water samples incubated in the laboratory the viable counts of heterotrophic bacteria reached the counts in reservoir water within 5 d. The increase in viable counts was mainly due to reactivation of bacterialcells damaged by u.v. light, not because of bacterial multiplication. Despite u.v. irradiation the bacterial numbers in the reservoir water, including legionellas, did not decrease during the experimental period of 33 d. The main growth of bacteria in the reservoir occurred in biofilm and sediment, which were never exposed to u.v. irradiation.     

Limnological Observations on Rihand Reservoir (Uttar Pradesh) with Reference to the Physical and Chemical Parameters of its Water

Observations in respect of Rihand Reservoir based on monsoon inflow, reservoir level, evaporation loss, air and water temperature, rainfall and wind velocity have been discussed in relation to the physical and chemical parameters of the water body. A weak thermocline has been observed, and the water showed a biogenic chemical stratification during the warmer months. Rihand is a monomictic tropical lake with a moderate nutrient supply, but is not very productive from the limnological point of view. The nutrient content of this lake declined from 1972 to 1974, but improved in 1975 and 1976 with the increase in rain and inflow of water. The productivity of the reservoir depends greatly on the nutrient level of the inflowing water from the catchment area, so that the monsoon inflow largely influences the water quality of the reservoir.     

Observation of anoxic water mass in a tropical reservoir: the Cirata Reservoir in Java,Indonesia

We conducted a transect survey of water quality and bottom sediments in a large tropical reservoir, the Cirata Reservoir, located on the Citarum River, West Java, Indonesia. In the main basin of this reservoir, the surface water contained high concentrations of chlorophyll a, up to 48 μg l⁻¹, and most of the water body was occupied by thick anoxic water. The thickness of the surface oxygenated water was only 5–7 m, whereas that of the anoxic water mass was more than 70 m. The concentrations of phosphate and ammonia were quite high in the anoxic hypolimnion. The reasons for the formation of the huge anoxic water mass include the oligomictic status of circulation, a relatively weak mixing caused by topography, high hypolimnion temperature, and high loads of organic matter. The carbon/nitrogen (C/N) ratios and the carbon stable isotope ratios of sediments indicated that the major source of organic carbon in the sediments was algal production in the reservoir and fish culture activity. The mechanism of eutrophication in the reservoir is also discussed.     

Analysis of consequences of contribution from major sources of chemical matter in water of novosibirsk reservoir

The contribution of chemical matter from major sources to the composition of water in the Novosibirsk reservoir is assessed. It is confirmed that the chemical composition of water in the Novosibirsk reservoir is essentially formed due to the inflow of chemicals from the Ob’ river.     

北京半城子水库水体营养物质表观沉降速率

表观沉降速率是流域非点源污染模型中反映水体营养物质通过不同过程,输移进入水库沉积物净效果的参数。选择位于密云水库上游的半城子水库进行水体营养物质监测,计算营养物质表观沉降速率,分析其影响因素,主要得出以下结论:半城子水库TN表观沉降速率平均为55.5mm/d,TP表观沉降速率平均为25.2mm/d,相对于世界其它地区的湖泊水库而言,TP表观沉降速率较慢。水体营养物质表观沉降速率受表层水温和水流条件共同影响。TN表观沉降速率均随表层水温的升高而递增。上游来水后,水体中P元素则经历了内源磷快速释放,之后快速沉降的变化过程。研究成果可为水污染防治和流域环境综合治理提供理论依据。