Phytoplankton pigments as ecological state indices of the Cheboksary Reservoir

Data on the composition and content of plant pigments in water of the Cheboksary Reservoir collected in 1985–2005 are used to analyze the seasonal dynamics and spatial distribution of phytoplankton at different stages of reservoir life. A trophic burst could be distinctly seen in the reservoir in 1985, manifesting itself in exceedingly high (198 ± 41 μg/l) concentrations of photosynthetic pigment chlorophyll. In the process of ecosystem stabilization, chlorophyll concentration significantly dropped to vary from 8.2 ± 1.5 to 45.1 ± 21.0 μg/l in 1989–2005. The reservoir, located in a region subject to high anthropogenic load, has acquired the features of an eutrophic water body immediately after its creation and its trophic status remains unchanged all over its existence.     

The Effect of the Hydrological Regime in the Rybinsk Reservoir on the Distribution and Dynamics of Benthic Cyclops

Data on the abundance, horizontal distribution, and the seasonal dynamics of the dominant species and the entire group Cyclopoida in the meiobenthos of the open littoral and profundal of the Rybinsk Reservoir are presented. The probability that the passive and active migrations of cyclops in the reservoir are controlled by the natural (transsedimentational activity of hydrodynamic processes) and human-induced factors (artificial water level control) is discussed.     

Status of Water Quality in King Talal Reservoir Dam,Jordan

This work intends to monitor and assess the current water quality conditions at King Talal Dam (KTD), Jordan, based on vertical profiles and longitudinal surveys. While the surface distribution of water quality parameters in KTD varied spatially, their variations showed no distinct trends. Lateral and horizontal variations in water quality in KTD are probably linked with photosynthesis, sampling period, closeness to Zarqa River and Wadi Rmemeen, and water depths, among other factors. The vast majority of water quality parameters in KTD dammed reservoir showed vertical profiles that either decrease slightly with increasing depth from the surface (temperature and dissolved oxygen) or remain relatively unchanged (major ions, trace elements). These results suggest that water has probably been vertically mixed. Data also demonstrated rock weathering as a dominant process governing the water chemistry of KTD reservoir water. Based on chlorophyll- a classification of Forsberg and Ryding [19], KTD reservoir is in a mesotrophic-eutrophic condition. Evaluation of water quality for irrigation use revealed that KTD reservoir water is suitable for irrigation purposes, except for Na% and total hardness.     

Changes in Water Quality in the Bureiskoe Reservoir Caused by a Large Landslide

Water Resources - The study considers the factors that had an effect on water quality in the Bureiskoe Reservoir (Far East) after a large landslide event in December 2018 (with a volume of 24.5...     

Mineral water formation in the eastern part of the Cheboksary deposit

The results of multidisciplinary uranium-isotopic and microelement hydrochemical studies were used to establish that mineral waters in the eastern part of the Cheboksary reservoir have formed from mixing of strata waters of Tatarskie deposits with a deep water, entering through fractured-weakened zones of deep faults of the Gor’kii-Kil’mezskaya lineament zone.     

On Relationships between Characteristics of Benthic Communities and Some Characteristics of Their Habitat

Relationships between the principal characteristics of benthic communities, physical characteristics of soil, depth, current rate, and the concentration of pollutants in the soil and water of the Gorky and Cheboksary reservoirs are investigated. Numerous significant correlations are found to exist between these characteristics. It is recommended that the assessment of water quality by characteristics of benthic communities should be made with a great caution.     

Application of Water Quality Index and Water Quality Model QUAL2K for Evaluation of Pollutants in Dez River,Iran

Water Resources - Dez River in Iran is a long river and has generally good-quality water. Unfortunately, in this river water quality has decreased over recent years due to drought, industrial and...     

浙江瓯江开潭水库库区浮游植物与水质的关系

通过2001年7月-2002年6月对瓯江开潭水库库区水体浮游植物的调查,以及对溶解氧和叶绿素a等理化指标的逐月测定,结果表明：该水域共有浮游植物7门40属82种(包括变种),其中以绿藻门和硅藻门的种类占优势,浮游植物的群落类型为绿藻型和硅藻型为主,种类和数量随季节和水域不同而呈现差异,水体营养特征为浮游植物响应型,水体向中营养化发展趋势明显,部分水体受到不同程度污染．     

Water Self-Purification in the Mozhaisk Reservoir in Winter

The results of determinations of the concentration and demand of oxygen for the decomposition of organic substances in water masses and bottom sediments of the low-flowage Mozhaisk reservoir are presented. The considerable spatiotemporal variability of these characteristics within this ice-covered water body is shown to be controlled by differences in the temperature, salinity, and organic matter content of different water masses constituting this ecosystem. It is noted that this water body forms a winter-type density stratification and oxygen-bearing circulation of waters that is caused by a density current. On the basis of daily O₂ budgets calculated by means of a quasi-two-dimensional hydrological model of the reservoir, the processes of the winter self-purification of water are shown to account for 50% of the oxygen supply. The discrepancy of this model was shown to be < 5.5% both for the entire water body and for its four constituent regions.     

The Space and Time Variations of Water Quality and Water Pollution Dynamics in the Oka Basin

Water Resources - The space–time variations in the Oka basin water chemistry have been considered. The specific features in the river water and groundwater pollution along the Oka channel and...     

Microbiological Characterization of the Ivan'kovo Reservoir Water

The current state of the Ivan'kovo Reservoir bacterioplankton is assessed. Data on the total number, biomass, and production of planktonic microflora are presented. The concentrations of active bacteria and their detritus are determined. The distribution of saprophytic microflora is studied.     

于桥水库的水质保护与渔业生产

大水面增养殖将水体中的氮、磷、有机物转化成鱼产品,并以渔获物的形式输出水体,从而加大水体氮、磷、有机物的输出量,有减缓水体富营养化、净化饮水水质的作用;同时鱼类的摄食、消化、排泄等新陈代谢活动可加速水中氮、磷等物质循环,使藻类繁衍,如果大量放养草鱼还会导致水草资源破坏、生态失衡,对饮水卫生、安全不利;网箱养鱼投入饲料,直接增加了水源有机污染。围网养殖对局部水域生态平衡有破坏作用,放养密度过大,投入     

南水北调中线水源区浮游植物

通过对南水北调中线水源区水体浮游植物的调查,结合理化指标的逐月测定,结果表明:该水域共有浮游植物8门40属71种(包括变种),其中以硅藻门的种类占优势,浮游植物的种类和数量随季节和水域不同而呈现差异,浮游植物对水体污染具有较好的指示作用,水体为寡污型水体.本研究为建立中线水源区长期生态研究数据信息库及库区生态环境保护政策制定提供科学依据.     

Evaluation of Sea Water Quality in the Coastal Zone of Primor'e Using the Method of Microbial Indication

The response of marine microorganism community to variations in the concentrations of heavy metals in the environment is investigated for the coastal waters of Peter the Great Bay and the northern part of Primor'e. The fact of the existence and sensitivity of the individual response of plankton community microorganisms to variations in the concentrations of metals in the water under the conditions of water contamination with a complex of metals are confirmed on the basis of microbiological data and the results of their comparison to the data of chemical analysis. Microbial indication is shown to serve as an operative method of monitoring and short-term forecasting of changes in the environmental conditions of sea coastal waters. This method allows obtaining preliminary information at the stage of selecting environmental quality observation stations.