Evaluation of the effects of seasonal changes in sediment characteristics on macroinvertebrate assemblage in a tropical reservoir

Osinmo Reservoir is an important water body in south‐western Nigeria. Despite being critically important, there is a lack of detailed biological studies on this reservoir. This study investigated the effect of seasonal variations on the characteristics of the sediment and the community structure of the macroinvertebrates in the reservoir between May 2012 and March 2014. The sediment was generally slightly acidic and was dominated by silty sand and sandy mud with low organic matter. Twenty‐four taxa of macroinvertebrates with a total abundance of 55,065 individuals (ind.) belonging to three phyla were recorded. Overall, the composition and the abundance of the macroinvertebrates were not significantly different (P > 0.05) in the wet and dry seasons. Seasonal variations in the sediment quality did not have a significant impact on the community metrics such as species diversity, species richness and species evenness. The dominance of sensitive species indicated a moderately clean status of the reservoir.     

Modelling the surface circulation and thermal structure of a tropical reservoir using three‐dimensional hydrodynamic lake model and remote‐sensing data

Diurnal variations in surface circulation, heat budget and thermal structure were investigated in a tropical reservoir using a synergistic approach that combines in situ observations, remote‐sensing data and numerical modelling. The study area, the Itumbiara Reservoir (Brazil) at the beginning of the austral winter, is characterized by the presence of a weak thermal stratification and the passage of several cold fronts. Both in situ observations and numerical modelling showed that the surface circulation is wind‐driven. The strongest water current was observed at 13:00 h, which lagged behind the strongest wind. The daily heat budget was negative during the period and was controlled by short‐wave radiation and latent heat flux. The diurnal cycle of stratification was at its maximum at 17:00 h, and the surface mixed layer deepens at night. The colder waters of the Paranaíba River contribute to the stability of the water column near the river‐reservoir transition zone.     

Relationship between macroinvertebrate fauna and environmental variables in small streams of the Dominican Republic

Field assessment methods for freshwater macroinvertebrates and water quality in tropical small-island states were assessed in the Dominican Republic. Macroinvertebrate samples were collected from 26 river sites within the Dominican Republic's Yaque del Norte river catchment. Environmental data on geographical, physical and chemical variables were also collected from each site. The Biological Monitoring Working Party score and total numbers of Ephemeroptera and Trichoptera were calculated for each site. Physico-chemical and biological data sets were ordinated by principal components analysis and non-parametric multi-dimensional scaling, and the biotic and abiotic data sets were correlated to determine the most influential factors determining site similarities. Macroinvertebrate assemblage structure was correlated with declining water quality: however, a high correlation between water quality and altitude confounded an unqualified interpretation of impairment.     

三峡库区网箱养鱼对周围水质的影响

以朱衣河二道河湾回水区网箱养鱼水质的现场监测结果为基础,采用综合营养状态指数法对网箱养鱼水域的现状进行了营养状态评价,并用污染物浓度等值线法进行了网箱养鱼对周围水质的影响分析.结果表明:网箱养鱼及其影响区的水体综合营养状态均为轻度富营养,水质污染程度为轻度污染,其综合营养状态变化总趋势为网箱养鱼区大于网箱影响区;网箱养鱼影响区的Chla浓度明显高于网箱核心区,其余污染物浓度的平面分布总趋势是由网箱核心区向网箱影响区由高向低变化;若以超河流背景断面浓度5%作为划定超背景污染带的标准,则朱衣河二道河湾网箱养鱼引起CODMnNH3-N、TN、TP和Chla超背景的污染面积分别为35 000、22 500、23 760、54 000和16 000 m3,分别是网箱养鱼区面积(3 900 m2)的9、5.8、6.1、13.8和4.1倍.     

浅谈钢筋混凝土蓄水池的施工和质量要求

介绍了钢筋混凝土蓄水池的用途，阐述了钢筋混凝土蓄水池的施工过程及主要分项工程的施工要点和质量要求，并对水池满水实验做了陈述，以供类似工程参考借鉴。     

浅谈南水北调工程建设过程中的环境保护和水土保持

南水北调工程属于线性工程,施工环境复杂,环境保护和水土保持工作采取施工单位具体实施、监理单位进行监督、建管单位检查验收的管理模式,并介绍了具体实施措施。     

集对分析及在地下水环境质量评价中的应用

集对分析是处理不确定性问题的新的系统理论方法 ,本文利用该理论 ,以水质为主要评价因子 ,提出了地下水环境质量评价新方法。     

石河子蘑菇湖水库富营养化成因及防治对策

根据大量的监测数据，分析了蘑菇湖水库富营养化的成因，阐述了水体富营养的防治对策，并提出了蘑菇湖治理的建议，以期恢复磨菇湖水库的生态功能，促进社会的可持续发展。     

Effects of run‐of‐the‐river hydropower plants on the surface water quality in the Solakli stream watershed,Northeastern Turkey

In recent years, Turkey has turned its attention to alternative energy sources rather than fossil fuels. The Eastern Black Sea Region of Turkey has steep mountains with hilly topography and has large potential in terms of energy production with run‐of‐the‐river hydropower plants (RHPPs). In this study, the effects of two RHPPs on some water quality parameters were examined in the Solakl? stream watershed. This research was conducted over the course of 12 months (January–December 2014). In total, 12 sampling points were selected and various water quality parameters, such as temperature, pH, dissolved oxygen, total suspended solids, electrical conductivity, total dissolved solid, chloride and salinity, were monitered at each point. Statistically, significant changes occured in water quality parameters such as total suspended solids, pH and temperature. In particular, total suspended solids ranged from 10 to 440 mg/L.These results suggest that the RHPP negatively effect water quality and quantity in the main stream in both the operational and constructional phases.     

A model for identifying the vulnerability of streams and rivers to land use-induced changes

This article describes a model for identifying the vulnerability of streams and rivers to land-induced change. Landscape architects are frequently asked to make land use recommendations which affect landscape change. The challenge is to organize information to aid landscape architects in making responsible recommendations. This model considers three types of spatial information: (1) sources of land use-induced change; (2) intensity of drainage within watersheds; and (3) sensitivity of drainage basins to change. The model also demonstrates the use of a Geographic Information System (GIS) and its application. The strength of this model is that it provides landscape architects with both time- and cost-efficient means of assessing the vulnerability of streams and rivers with existing data. It further directs site-specific investigation to areas which are identified and prioritized with regard to the relative vulnerability of streams and rivers to land-induced change.     

Analysis of triclosan and 4n‐nonylphenol in Colombian reservoir water by gas chromatography‐mass spectrometry

In this work were determined triclosan and 4n‐nonylphenol in water from a reservoir that is used to provide water to a purification plant in an important city in Colombia. The analytical methodology was validated using solid‐phase extraction and analysis by gas chromatography‐mass spectrometry (GC‐MS). The analysis by GC‐MS showed good linearity in the range of 0.05–5 μg/L for both compounds. Recoveries from 79 to 109% and standard deviations of 2.5–7.7 for low concentrations and from 3.8 to 9.6 (n = 5) for high concentrations were obtained for both compounds. In Colombia, this is the first time that these compounds have been analysed in water supplying of a drinking water treatment plant. The validated method was applied to the analysis of 27 samples collected in August 2010 in 11 locations from the reservoir and in the influent and effluent of the drinking water treatment plant. In total, seven samples were found to contain triclosan.     

Farmers’ willingness‐to‐pay towards soil and water conservation measures in agro‐ecosystems of Chotanagpur Plateau,India

Lack of importance given to farmers’ knowledge and perceptions towards soil and water conservation (SWC) is a major factor responsible for failure of conservation programs. The study explores farmers understanding of SWC and further adds to the limited empirical evidence towards farmers’ willingness‐to‐pay (WTP) for SWC. Contingent valuation survey conducted to elicit the WTP (cash and labor days) for SWC draws attention to the importance of adopting SWC to ensure year‐round water availability. The willing households of the area could generate US$1302.2 and/or 1207 labor days monthly. The WTP (cash) showed strong positive influence by qualification, total income, off‐farm income and previous irrigation farming experience; while WTP (labor days) showed strong negative influence by age, qualification, dependency ratio, market access and livestock holding. The study will be useful for decision makers regarding investments and policy purposes for soil–water conservation measures in agricultural lands of developing countries.     

Barrage Developments in the Welsh Region: The Role of the National Rivers Authority in Protecting the Aquatic Environment

During recent years, barrages and marina developments have increasingly been viewed as a means of improving the aesthetic and recreational qualities of degraded urban areas, thereby encouraging inward investment. However, barrage schemes can have major implications for the National Rivers Authority's statutory responsibility for flood defence, fisheries, recreation, water quality and conservation.
The experiences gained by the National Rivers Authority's Welsh Region in its negotiations with promoters of the Tawe, Cardiff Bay and Usk barrages are presented. The paper describes the environmental safeguards secured for the Tawe barrage, together with some initial assessments of its impact on the aquatic environment following its completion in 1992. The experience gained with the Tawe barrage has contributed to a more rigorous approach being applied by the National Rivers Authority to the Cardiff Bay and Usk schemes.     

Influence of water and sediment quality on benthic biota in an acidified river

Water and sediment quality and benthic biota were investigated in all seasons during three years in the River Akagawa that receives the effluent from a mine drainage treatment plant at its upstream site. The upper reaches kept the low pH, the comparatively high concentrations of metals and a large amount of iron deposited on the riverbed. The predominant macroinvertebrates were Protonemura sp., Capnidae, Nemoura sp. and Chironomidae in the upper and middle reaches. In the lowest reaches, the community structure of the macroinvertebrate changed into Chironomidae, Trichoptera (Hydropsychidae) and Ephemeroptera (Baetis sp.) as the pH was increased. From the results of multivariate analyses, it was found that the restoration of pH and attached algae and the increase in the concentrations of nutrients and organic matter promoted the inhabitation of Chironomidae and Hydropsychidae, whereas the dissolved metals in the river water inhibited the inhabitation of these families. Moreover, the sedimentation of metals would cause a severe damage to the inhabitation of Hydropsychidae compared with that of Chironomidae.     

试论节能环保技术在建筑施工中的应用

节能环保技术作为现代化社会发展当中的必然产物,其在建筑施工当中的应用,不仅能够提高企业的经济效益,还能够为企业的未来发展打下良好的基础。笔者结合实践工作经验,对节能环保技术在建筑施工中的应用进行了探讨。     

钢筋混凝土结构清水池施工问题及处理方法

对钢筋混凝土结构清水池施工中常见的地基处理、金属止水带的位置与预留孔洞交叉、现浇混凝土使用、围护墙的施工等方面问题的技术处理方案进行了分析阐述,以供类似工程参考借鉴。     

Erosion externalities: an empirical study of resident beliefs for a watershed in south‐eastern Spain

This research explores the external effects of erosion as a criterion based on the perceptions of residents of populated areas within a watershed. We applied a multiple correspondence analysis to survey responses in order to reveal the attitudes of residents towards erosion in the study area. This analysis is combined with an analysis of the adjusted residuals, with the goal of identifying the most important erosion externalities that characterize part of south‐eastern Spain. Our results demonstrated that the survey approach, combined with the statistical analysis, is capable of revealing differences among communities within a watershed in the perceived externalities of erosion. We identified the following key variables: municipality, conservation status of access routes, conservation status of sewer systems, conservation status of landscape, nature outings per year and agriculture abandonment.     

黄河三角洲地区多水源联合调度及其环境效应研究

黄河三角洲地区南部广饶县处于淄河冲洪积平原与三角洲海积冲积平原交接部位,因形成以花园和稻庄为中心的地下水降落漏斗而造成北部咸水以3.0km~2/a的速度向南入侵。建立该区地下水、地表水和引黄河水多水源联合调度优化模型,其目标函数是使各时段研究区地下水位降深之和最小,其约束条件包括供水量、开采井取水量、引黄河水量、节水量、水位等。预测结果表明,每个区采取包括节水、减少地下水开采量、拦蓄地表水或引黄河水补给地下水、井灌区改为渠灌等不同措施,到2010年,花园和稻庄漏斗中心水位将分别由过去的低于-20.00m上升为-14.00m和-12.66m; 2003年后,能够在稻庄北部形成反漏斗(淡水帷幕),阻止北部咸水入侵。环境效应显著。     

水环境评价参数空间变异模拟数学原理与方法

对环境评价参数空间变异的二重性特征进行了分析 ,论述了环境评价参数空间变异模拟的数学原理与方法。由于所采用的方法能够弥补经典统计数学方法对环境评价参数空间变异随机性分析的不足 ,因而能够获得这类参数空间变化的结构性信息及空间最优估计值 ,使得对环境评价中各种参数空间变异不确定性的分析与评价趋于合理。     

郑州植物园展览温室节能环保新技术应用

郑州植物园展览温室工程从节约能源降低运营费用的角度,对各个分系统和总系统进行节能设计,既满足了展览温室的技术需要,又达到了节能环保的时代要求,取得了较好的经济和社会效益