Trends in the use of large wood in UK river restoration projects: insights from the National River Restoration Inventory

Large Wood (LW) is increasingly employed in river restoration to promote physical habitat heterogeneity and ecological diversity. To explore how LW has been used in restoration schemes across the United Kingdom in recent decades, we analysed data on 912 LW projects archived in the UK’s National River Restoration Inventory (NRRI). The number of LW schemes has continued to increase following the earliest records in the 1990s, largely tracking overall trends in river restorations. LW projects have been predominantly located in lowland, rural streams, although there has been a notable cluster in and around London. LW projects have mainly revolved around the desire to deliver hydromorphological improvements and specifically the creation of fish habitat. Most schemes used LW in simple deflector forms despite the growing scientific evidence of the benefits of using structurally complex LW. Post project monitoring has been limited and mostly restricted to photographic records. This type of database analysis can provide important insights and help guide future restoration practice.     

A preliminary pressure–impact analysis applied in the Pinios river basin (Thessaly, Central Greece)

Greece has not yet undertaken one of the first and most important tasks required by the Water Framework Directive (WFD: the integrated review of the impact of human activity on the status of surface waters for each river basin – the IMPRESS analysis. Owing to the lack of a national methodology, a preliminary analysis was carried out for the Pinios river basin, applying a combination of different methodologies refined to suit the particularities of the Greek freshwater environment and to accommodate the limited availability of data. Pressures caused by the main pollution sources, point and nonpoint, were quantified in terms of pollution loads with the use of emission factors. The existing limited biological and physicochemical monitoring data were used to assess impacts. Additionally, we identified pressures caused by alterations from land-use data; we carried out a River Habitat Survey (RHS) and estimated the hydromorphological impacts through the calculation of a Habitat Modification Score (HMS). Our results suggest that the probability of the Pinios river basin failing to achieve good ecological quality by 2015 due to pollution is high, and due to hydromorphological pressures is moderate.     

浅谈晋江市河流生态修复的对策

通过晋江市河流生态环境所存在的问题和成因分析,结合当前晋江市河道建设中存在的已改建、部分改建、自然状态的三种实际情况,提出了＂分河段、分阶段＂的生态修复对策和建议,以改善河流生态环境,最终实现河流的生态修复,为今后城市河流生态修复建设提供借鉴。     

Degradation of atrazine in a laboratory scale model system with Danube river sediment

A laboratory-scale model system of Danube river gravel bed was constructed. Evaluation of water chemical parameters and composition of bacterial communities confirmed the liability of the model. Degradation of atrazine, a frequent micropollutant of Danube water was examined in the model system. In case of an acute atrazine load, short-term retention of the compound was observed, accumulation and degradation were not significant. Long-term continuous dose of atrazine led to enhanced degradation of the pollutant. Principal metabolite was hydroxyatrazine. Atrazine utilizing strains isolated from the sediment belong to various, predominantly Gram positive genera and have diverse atrazine metabolism. Dominant metabolic reactions are dechlorination, dealkylation and deamination, with the sequential products ammeline and ammelide. The strain Delftia acidovorans D24 mineralizes atrazine as a sole source of carbon and nitrogen.     

Restoration of a chalk stream using wood: assessment of habitat improvements using the Modular River Survey

The installation of large wood and sediment berms to narrow the overwide channel of the River Bulbourne, Hertfordshire, aimed to restore geomorphological processes, improve channel habitat diversity and increase the amenity value of the park in which the river is located. The Modular River Survey provides a framework and suite of tools for river managers and volunteers to monitor and assess restoration activities. Applying this technique to the River Bulbourne before and after restoration demonstrated that the works increased physical habitat and vegetation complexity. The restored section was narrowed, substrate composition changed and the range of in‐stream vegetation morphotypes increased. The initial slight improvement in riparian habitat complexity immediately following the restoration is expected to increase further over time as the riparian vegetation develops and the restored section of channel matures. A public perception and recreational use survey reviewed how visitor experience and use of the park changed following restoration.     

River restoration: what are we restoring to? a case study of the Ravensbourne river, London

State of the art techniques are now being developed to restore our rivers to improve their ecological and conservation value, as well as enhancing their amenity and recreation potential. This study focuses upon the restoration of a small section of the Ravensbourne River in a suburban park near London (Queen's Mead Recreation Ground), which was channelized in the 1970s for the purposes of flood control. As well as reviewing the current status and progress in river restoration, and the feasibility of carrying out such works, the paper asks “what are we restoring to"? Is it to a rural pre twentieth century river character, or are we creating a controlled version of nature? The history of the river is examined along with possible options for restoration. Finally, results from two public perception surveys are outlined which indicate substantial support for restoration. The paper also raises the question of whether the term 'restoration' is an appropriate one to use.     

Assessment of the hydromorphological state of Carpathian rivers above and below reservoirs

The article presents the results of an assessment of the hydromorphological state of selected Carpathian rivers in sections above and below the reservoirs. An attempt has also been made to assess the impact of reservoirs on the hydromorphological conditions and quality of river habitats. The research was based on the River Habitat Survey (RHS) method. The synthetic indices Habitat Quality Assessment (HQA) and Habitat Modification Score (HMS) were calculated on the basis of the gathered data for each section studied; this allowed the hydromorphological qualities of the rivers to be assessed numerically. The reservoirs interrupt river continuum, and they alter different biotic and abiotic elements of natural environment. However, this study has shown that the operation of reservoirs does not always negatively impact the hydromorphological conditions of rivers that reflect their habitat quality. The influence of reservoirs on a river's hydromorphological state above and below a reservoir's location may be neutral, but it also can improve the habitat conditions of a river.     

Assessing landscape change and biodiversity values of the Middle Vistula river valley, Poland, using BIO-SAFE

This paper deals with the relation between legally protected biodiversity and riverine ecotopes and with the assessment of biodiversity values of the Middle Vistula river valley (Poland). Furthermore, it describes the effects of landscape change on spatial distribution of ecotope patches and biodiversity values in Kazimierski Landscape Park. Biodiversity values were calculated using BIO-SAFE, a model meant to quantify biodiversity and to value ecotopes based on legally protected species. Dissimilarity indices depict high uniqueness of ecotope types regarding their species assemblages (e.g., river dunes, banks and bars). The actual biodiversity values of the river valley in Kazimierski Landscape Park are high in comparison with floodplains of lowland rivers in Western Europe. GIS analyses of remotely sensed ecotope maps show remarkable differences in number, acreage and patchiness of ecotopes for the years 1953 and 2003. The total number of patches increased by almost 44%. Side channels and floodplain lakes became fragmented. The average and total surface area of bush, forest and arable land increased, but decreased for bare soil, pioneer vegetation and grassland. These landscape changes indicate natural vegetation succession, intensification of agriculture and progressive impacts of river regulation. The Vistula river valley still represents high biodiversity values for higher plants, birds, herpetofauna and fish. However, current landscape changes negatively affect potential values for protected and endangered species. Assessments with BIO-SAFE can help to balance biodiversity conservation, river management and landscape planning.     

Developing a new method for spatial assessment of drought vulnerability (case study: Zayandeh‐Rood river basin in Iran)

The paper presents an approach to spatially representative depiction for assessing the vulnerability of central Iran's Zayandeh‐Rood river basin to drought using multiple indicators. Drought conditions prevailed in the study basin from 2002 to 2007, with an annual rainfall deficiency of 45 to 55%. Multi‐attribute decision making (MADM) methods develop a framework to evaluate the relative priorities of drought assessment based on a set of preferences, criteria and indicators. The proposed MADM process uses well‐known techniques for product weights analytic hierarchy process (AHP) and order preference (TOPSIS). These indicators include the Standard Precipitation Index (SPI), water demand, the Palmer Drought Severity Index (PDSI) and the Groundwater Balance and Surface Water Supply Index (SWSI). Indicators' spatial information was categorised in layers prepared in the spatial domain using a geographic information system (GIS). The alternatives were ranked and presented using TOPSIS. Results show that the proposed method was highly effective in representing assessments of drought vulnerability.     

Deculverting: reviewing the evidence on the ‘daylighting’ and restoration of culverted rivers

We review published references on ‘deculverting’ (also known as ‘daylighting’) projects in the United Kingdom and internationally. The aim of the review was to assess the objectives of implemented projects and to establish where evidence exists for the purported social, economic and environmental benefits of deculverting. The outcomes highlight the need for collaboration to collate detailed information on such projects, to support the further development of evidence‐based policy. It is clear that deculverting schemes can indeed exert considerable positive impacts, including ecological benefits, reduced flood risks, recreation for local communities and a stimulus for regeneration, but that the evidence for these impacts is sparse. We conclude that improvements in policy will help to maximise these opportunities, by encouraging the implementation of good practices.     

Influence of eco‐hydrological factors on aquatic plant succession in a regulated river: a case study of the Petchburi River,Thailand

Monitoring of aquatic plant biomass in the Petchburi River, a regulated river system in Thailand, was carried out together with the examination of eco‐hydrological characters and the sedimentary organic content. The surveys were performed during May, August and November of 2010 and 2011. The results indicated temporal variation in water velocity (0.08–2.51 m/s) and medium to low organic levels (0.58–4.68%) of the benthic substrates. Dominant aquatic plants were Hydrilla verticillata (L.F.) Royle and Potamogeton malaianus Miq. with the highest biomass of 70.84 and 182.72 g/m², respectively. The biomass was substantially decreased during the flood‐induced discharge period. This study indicates that Potamogeton has more adaptive potential to high water velocities than Hydrilla, while Hydrilla prefers lower water velocities. Discharge velocities of less than 0.5 m/s could provide positive growth rates of such submerged plants. Approaching the discharge control from this ecological point of view can further contribute to river habitat conservation.     

Carbon source utilization‐based metabolic activity of Salmonella Oranienburg and Salmonella Saintpaul in river water

The presence of introduced or non‐native bacteria in river water can create a selective pressure due to their ability to overcome fluctuations in physicochemical conditions and carbon source availability. The carbon source concentrations (monosaccharides and polysaccharides), physicochemical parameters (turbidity, total dissolved solids, biochemical oxygen demand, temperature and pH) and metabolic activity of Salmonella Oranienburg and Saintpaul were determined in water from the central Sinaloa state rivers. This study's results revealed that the carbohydrate availability and physicochemical conditions of river water make it a suitable niche for the establishment of Salmonella serotypes. Metabolic profiles showed that Salmonella Typhimurium could consume a wide variety of carbon sources but only at moderate levels; in contrast, Salmonella Oranienburg and Salmonella Saintpaul demonstrated intense carbon source utilization of a limited diversity of carbon sources. Carbohydrates, amino acids and carboxylic acids were the metabolites most utilized by the environmental Salmonella strains, demonstrating their superior ability to adapt to and survive in river water.     

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.     

Dynamic performance evaluation of Shanghai Tower under winds based on full‐scale data

Shanghai Tower is the tallest building in China with a height of 632 m. This study aims to investigate the wind characteristics and its impact on Shanghai Tower so as to provide useful information for the wind‐resistant design of 600 m+ super‐tall buildings. By analyzing the data of wind speed during the occurrence of DeHong in June 2017, the relationship between turbulence intensity and mean wind speed is verified, and the correlation between gust factor and turbulence intensity is confirmed. Apart from that, it is also found that the von Karman spectrum fits well with the measured fluctuating wind speed spectrum. In addition, the 83rd and 117th acceleration data are analyzed to obtain the natural frequency by peak‐picking, frequency domain decomposition, stochastic subspace identification, and fast Bayesian fast Fourier transform methods. The amplitude‐dependence dynamic parameters of Shanghai Tower on the basis of the field measurements are studied as well. Finally, the wind‐induced vibration is investigated based on the acceleration data and wind speed data, which verifies that the responses along two main axes having a similar amplitude under wind effects. The occurrence of DeHong demonstrates that a gale equivalent to a typhoon may occur in urban areas without any urban warning.     

Evaluation of the water quality in the Guadarrama river at the section of Las Rozas‐Madrid,Spain

The variation of the water quality of the Guadarrama river and its tributaries in a section of Las Rozas‐Madrid, Spain, was studied during the time period between January 2003 and January 2008. The parameter water quality index (WQI) was used to determine the water quality based on the conventional parameters of pollution. It was found that the WQI was slightly affected in the section evaluated. The value of the WQI was in the range of 56–64, which corresponded to the classification of ‘good quality’. It was determined that 64.3% of the organic matter present in the river was removed in the section of Las Rozas‐Madrid. The river acted as a plug flow reactor and a first‐order kinetics governed the ultimate biological oxygen demand (BOD₅) (BOD_U) decay. The value of the first‐order constant demonstrated the river's high self‐purification capacity. In addition, a high linear relationship was found between the WQI and the dissolved oxygen deficit (D). Therefore, a quick determination of WQI may be carried out if the values of D are known. These are easily obtainable by field measurements.     

Assessment of the water quality and identification of pollution sources of Kaduna River in Niger State (Nigeria) using exploratory data analysis

Exploratory data analysis such as hierarchical cluster analysis and principal component analysis were applied to water quality dataset of the Kaduna River, obtained during 3 years (2008–2010), monthly monitoring of eight key different sampling sites for 19 parameters to extract correlations and similarities between variables and to classify river sampling sites in groups of similar quality. Hierarchical cluster analysis grouped eight sampling sites into three statistically significant clusters of similar water composition. Six varifactors were obtained after varimax rotation of initial principal components using principal component analysis. These techniques gave an insight into the sources of pollution. Anthropogenic influence (municipal, industrial wastewater and agricultural run‐off) was the major source of river water pollution.     

Comparative experimental study of full‐scale H‐subframe using a new industrialized building system and monolithic reinforced concrete beam‐to‐column connection

Industrialized building system (IBS) is a construction process that uses techniques, products, components or building systems that involve prefabricated components and on‐site installation. The structural behaviour of a prefabricated frame structure is widely affected by the specifications of the beam‐to‐column connection. The understanding on the real behaviour of a connection can be assessed by conducting full‐scale experimental tests. In this study, a new IBS hybrid steel–concrete connection in a full‐scale H‐subframe under monotonic loading is investigated. This innovative connection system, consists of precast concrete beam‐and‐column elements with embedded steel end connectors, is patented as Smart IBS. This paper reports the testing procedures and results of this semi‐rigid IBS beam‐to‐column connection to obtain the important attributes of the connection as well as its comparison with monolithic cast‐in‐place reinforced concrete model. The height of both H‐subframes is 3.3 m while the free length of the beam is 3.2 m. The incremental loads were applied as two point loads in one‐third and two‐third of the beam length. The characteristic relationships of the connection such as load to mid‐span deflection, strength, stiffness, ductility, failure modes and crack patterns are studied and compared between both structural systems. Copyright © 2012 John Wiley & Sons, Ltd.     

Electro‐oxidation of phenol in petroleum wastewater using a novel pilot‐scale electrochemical cell with graphite and stainless‐steel electrodes

This work investigated the removal of phenol from petroleum wastewater by the electro‐oxidation process. The experimental design was developed on a pilot‐scale electro‐oxidation system equipped with a cylindrical shape of graphite electrodes as an anode and stainless‐steel electrodes as a cathode. An initial study was performed based on operating variables such as current density and time on real petroleum wastewater. The optimum conditions were obtained as a current density of 3 mA/cm² and time 15 min. Under these applied optimum conditions, complete phenol removal from an initial concentration of about 6.8 mg/L was achieved. Also, 50–60% removal of organic matter in terms of chemical oxygen demand (COD) and biological oxygen demand (BOD). The removal of organic matter using electro‐oxidation requires a long reaction time. Also, the economic study indicated that the energy consumption was determined to be 0.79 kWh/m³ and the operating cost was 0.051 $/m³ which is very economical compared with conventional methods.     

Empirical evaluation of river basin sustainability affected by inter‐basin water transfer using composite indicators

In this study, a practical approach to evaluate the sustainability of river basins subjected to an inter‐basin water transfer project is developed. Selection of appropriate evaluation indicators is pivotal to such approach. To make use of huge amount of data, composite indicators of sustainability (CIS) should be utilised. The proposed approach relies on 15 sustainability indicators (SI) that cover three major criteria namely (economic, social and environmental), and aggregates them into eight different types of sustainability indices for a more robust outcome. Two scenarios were considered within the source and recipient basins. Furthermore, multivariate principal component analysis (PCA) was applied to determine principal and non‐principal indicators for the two river basins. The ability of CIS and PCA methods were verified via correlation and simple regression methods respectively. The results demonstrated that inter‐basin water transfer may improve sustainability, provided that a proper water resource management is enforced.     

Improved calibration of a rainfall‐pollutant‐runoff model using turbidity and electrical conductivity as surrogate parameters for total nitrogen

To address data scarcity for calibration of rainfall‐pollutant‐runoff (RPR) models, we evaluated the suitability of nutrient levels estimated based on surrogate parameters as a novel source of data, using runoff of total nitrogen (TN) in the Tegiru basin as a case study. A linear regression equation was developed for estimating TN based on turbidity and electrical conductivity; this expression was then used to generate TN data (n = 113) for calibration of a catchment‐specific RPR model. Using solely the estimated TN concentrations for calibration, the model accurately predicted TN concentrations (21% error based on measured TN, n = 13) and revealed runoff trends during periods in which TN measurements were lacking. Finally, we utilised this model to show that TN runoff was highest during months with frequent and high intensity rainfall. In summary, this study demonstrates the applicability of surrogate parameters to extend data on difficult‐to‐monitor nutrient loads for model calibration.