Journal of ecohydraulics最新文献

{"title":"Fish passage developments for small-bodied tropical fish: field case-studies lead to technology improvements","authors":"T. Marsden, I. Stuart","doi":"10.1080/24705357.2019.1646616","DOIUrl":"https://doi.org/10.1080/24705357.2019.1646616","url":null,"abstract":"Abstract In tropical coastal lowland rivers, there are frequently biodiverse upstream migrations of post-larval and juvenile diadromous fish from estuaries into freshwater. Tidal barriers completely block major migratory pathways for these fish and have contributed to major losses of freshwater biodiversity. In northern Australia, early efforts to improve tropical river fish passage with salmonid-style fishways completely failed. Since the mid-1990s, low gradient vertical-slot and rock fishways improved fish passage but the smallest and most abundant fish (i.e. from 10 to 100 mm long) often still failed to ascend. Since the mid-2000s, there was a paradigm shift in hydraulic design criteria for new fishways, with a renewed focus on: (i) low turbulence, (ii) maximized roughness and hydraulic boundary layers to optimise fish ascent. We used a combined methodology, firstly developing a conceptual model of fish movement to inform fishway design criteria, secondly tabulating past and present fishway design criteria, and thirdly conducting a series of brief field case-studies, at tidal barriers in tropical rivers for new technical and rock fishways. Our objective was to evaluate the success of these new designs for passage of very small (from 9 mm long) diadromous fish on low head barriers (i.e. <3 m high). We conclude that while there have been improvements in passage of small-bodied fish at tidal barriers further experimental work is still needed to test and refine current ecohydraulic fishway design criteria.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"116 1","pages":"14 - 26"},"PeriodicalIF":0.0,"publicationDate":"2019-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87815992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upstream movement of river lamprey through a culvert retrofitted with spoiler baffles under experimental conditions","authors":"A. Vowles, P. Karageorgopoulos, P. Kemp","doi":"10.1080/24705357.2018.1555777","DOIUrl":"https://doi.org/10.1080/24705357.2018.1555777","url":null,"abstract":"ABSTARCT Culverts used to convey river water under roads and embankments are one of the most common small-scale barriers to longitudinal fish movements worldwide. Using an open channel flume, this study assessed the ability of upstream migrating adult river lamprey (Lampetra fluviatilis) to ascend a pipe culvert when unmodified (control [C]) and retrofitted with spoiler baffles (treatment [T]) under three flow regimes (low discharge [L], high discharge [H] and high discharge with a raised downstream water level [HD]). Few lamprey attempted to ascend the culvert under low (11%) and high (21%) discharge in both the control and the treatments. Despite a greater percentage attempting to pass (75%) under HD, they frequently failed. Contrary to our predictions, upstream progress was impeded by the spoiler baffles and may reflect low motivation or avoidance of the physical and/or hydraulic conditions encountered. This study emphasizes the need to better understand the factors influencing the behaviour and motivation of fish as they ascend fish passage structures, and of the importance of reporting negative results as fish passage solutions that are promising for some species may be ineffective for others.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"54 1","pages":"107 - 99"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80162235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is the right scale? Encouraging fruitful engagement for ecology with ecohydraulics","authors":"J. Lancaster","doi":"10.1080/24705357.2018.1535260","DOIUrl":"https://doi.org/10.1080/24705357.2018.1535260","url":null,"abstract":"Abstract In ecohydraulics research, both physical and biological variables must be sampled at scales that are appropriate to the questions being addressed. This essay focuses on ecological topics that may be addressed in the context of ecohydraulics and the scales appropriate for their investigation. The first sections discuss definitions of scale, how environmental heterogeneity influences experimental and sampling designs, and the importance of recognizing that physical and ecological heterogeneity are not necessarily related. Thus, the scales appropriate for a particular research problem should be determined primarily by the ecological phenomenon of interest, plus the generation time and life-space of the study organisms. Studies over the large scales relevant to population and community ecology are logistically difficult and numerical models, but not scaled physical models, may facilitate extrapolations between scales for ecological phenomena. Three examples illustrate how complementary sets of studies executed at different scales can collectively contribute to ecological research problems in an ecohydraulics context. Two examples have strong roots in ecology (population dynamics in disturbed environments; ecosystem engineers) and the third arises from a need to solve applied problems (fish passage). These are topical areas of research to which ecohydraulics could make significant contributions.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"107 1","pages":"63 - 76"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77422511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The importance of a holistic ecohydraulics approach in advancing fish passage design","authors":"","doi":"10.1080/24705357.2019.1619990","DOIUrl":"https://doi.org/10.1080/24705357.2019.1619990","url":null,"abstract":"Recognition that monitoring the effectiveness of fish passes has tended to use non-standardized methods that make it difficult to directly compare between sites and structures on which generalized conclusions, e.g. using meta-analyses, can be formed has led to current efforts to develop a European Standard guidance document (currently a draft) for assessing fish passage efficiency. It is argued that only systematic, reproducible monitoring studies assessing the performance of fish passes will enable us to improve and develop current fish pass design. Despite describing the need for a multi-method approach, e.g. involving traps, observation, and laboratory studies, the focus of the draft standard is solely directed towards telemetry, a bias that is clear in other recent publications (e.g. Silva et al. 2018). While telemetry (e.g. acoustic, radio, and PIT tagging techniques) undoubtedly has an important role to play as part of a suite of methods that may be employed by researchers to better understand the key factors that influence fish passage efficiency, reliance only on this tool is problematic for a number of reasons. First, telemetry studies often provide valuable information, but are frequently constrained by the sitespecific context on which the case studies are based at the time they are conducted. Second, in situ field studies are unable to control for multiple confounding variables that have the potential to influence results on which conclusions are based. Third, even the most high tech and fine-scale telemetry techniques available are unable to obtain the detailed information on fish behaviour that may be achieved through direct observation. Fourth, telemetry is unsuitable for small bodied adult fish or juveniles of many species, a critical limitation in many understudied regions, such as in the temperate South (e.g. Chile and New Zealand; see Knapp et al. 2019 in a future issue of the Journal of Ecohydraulics). Finally, despite the high standard of current surgical techniques used by those proficient in telemetry, there remains the potential for tag effects that may influence behavioural and other responses (e.g. Jadot et al. 2005; Thorstad et al. 2013). Thus, in contradiction to statements made in the draft standard document, telemetry may have disadvantages, as well as “major advantages”, when compared to the other methods available, and is not the only means by which efficiency estimates can be formed as implied. Laboratory studies enable a variety of observation methods to be used (Knapp et al. 2019), ranging from tracking of fish trajectories to visualisation of flow patterns using techniques such as Particle Imaging Velocimetry (PIV) that are difficult to apply in the field (but see Biggs et al. 2019 in a future issue of the Journal of Ecohydraulics). In the current issue, Vowles et al. (2019) use a large open channel flume to assess the potential for spoiler baffles to improve passage of upstream migrating adult river lamprey (L","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"35 1","pages":"61 - 62"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82578236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sampling sufficiency for determining hydraulic habitat diversity","authors":"Severin Stähly, W. Gostner, M. Franca, C. Robinson, A. Schleiss","doi":"10.1080/24705357.2019.1576021","DOIUrl":"https://doi.org/10.1080/24705357.2019.1576021","url":null,"abstract":"Abstract The geometry and hydrodynamics of river reaches are key ecohydraulic descriptors. Statistics of water depth and velocity measurements are usually taken as proxies for habitat suitability in rivers. However, little is known about the sufficiency of data to produce effective and representative results. In this research, 19 reaches with differences in terms of discharge, river width, substrate, reach length, cross-section spacing and geomorphology are investigated. Measurements of flow depth and velocity were taken at multiple, equally spaced cross-sections along each reach. Data were sub-sampled using different methodologies and analysed each time. The sets of sub-sampled data were then compared with those calculated with the full data set from a reach. The focus was put towards the hydro-morphological index of diversity (HMID), a combination of the classical ecohydraulic variables flow depth and velocity. It represents the spatial variability of hydraulic habitats in a reach. The results point out that, with a well-defined sampling strategy, 100 measurement points lead to a good estimation of the HMID value in a reach, if more than eight measurement points are taken per cross-section. For geomorphologies with small complexity or when the analysis only includes the estimation of mean flow depth or mean flow velocity, this number can be decreased according to the results presented here. These findings help both, aquatic ecologists and engineers to estimate their data reliability for hydraulic field measurements in a river reach and are herein discussed taking into account the different studied morphologies.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"9 1","pages":"130 - 144"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84319047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The importance of riparian plant orientation in river flow: implications for flow structures and drag","authors":"R. Boothroyd, R. Hardy, J. Warburton, T. Marjoribanks","doi":"10.1080/24705357.2019.1573648","DOIUrl":"https://doi.org/10.1080/24705357.2019.1573648","url":null,"abstract":"Abstract In a series of high resolution numerical modelling experiments, we incorporated submerged riparian plants into a computational fluid dynamics (CFD) model used to predict flow structures and drag in river flow. Individual plant point clouds were captured using terrestrial laser scanning (TLS) and geometric characteristics quantified. In the first experiment, flow is modelled around three different plant specimens of the same species (Prunus laurocerasus). In the second experiment, the orientation of another specimen is incrementally rotated to modify the flow-facing structure when foliated and defoliated. Each plant introduces a unique disturbance pattern to the normalized downstream velocity field, resulting in spatially heterogeneous and irregularly shaped velocity profiles. The results question the extent to which generalized velocity profiles can be quantified for morphologically complex plants. Incremental changes in plant orientation introduce gradual changes to the downstream velocity field and cause a substantial range in the quantified drag response. Form drag forces are up to an order of magnitude greater for foliated plants compared to defoliated plants, although the mean drag coefficient for defoliated plants is higher (1.52 defoliated; 1.03 foliated). Variation in the drag coefficients is greatest when the plant is defoliated (up to ∼210% variation when defoliated, ∼80% when foliated).","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"73 1","pages":"108 - 129"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79160183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new settling velocity equation for cohesive sediment based on experimental analysis","authors":"Aisha Mhashhash, B. Bockelmann-Evans, S. Pan","doi":"10.1080/24705357.2018.1457987","DOIUrl":"https://doi.org/10.1080/24705357.2018.1457987","url":null,"abstract":"Abstract Cohesive sediment flocculates under particular circumstances, for example, the increase of salinity in the brackish zone of rivers, forming flocs that are larger and less dense than individual particles. The phenomenon of flocculation plays a significant role in the sediment transport processes of settling, deposition and erosion. This study used an extensive experimental setup using a particle image velocimetry (PIV) camera system to establish a new settling velocity equation as a function of salinity (S) and turbulence (TS). The results were compared with those of studies previously conducted at various estuaries. The experimental research was carried out in a 1 L glass beaker using suspended sediment samples from the Severn Estuary in the United Kingdom. A PIV system and an image processing routine were used to measure floc size distribution (FSD) and settling velocity. Based on the experimental data, Minitab was used to derive a new regression equation to predict the settling velocity.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"73 1","pages":"77 - 85"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79663404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of the compromise between power output and fish-friendliness in a vortex power plant","authors":"S. Müller, Olivier Cleynen, S. Hoerner, Nils Lichtenberg, D. Thévenin","doi":"10.1080/24705357.2018.1521709","DOIUrl":"https://doi.org/10.1080/24705357.2018.1521709","url":null,"abstract":"Abstract The characteristics of a vortex power plant integrated in a weir have been investigated using computational fluid dynamics, with a special focus on all flow properties relevant to fish migration and energy conversion. The numerical model relies on a Reynolds-averaged, unsteady description using the volume-of-fluid method to describe the free surface. Several monitors are implemented, quantifying, in particular, the distribution of water velocities within the plant, and the probability of impact between drifting objects and turbine blades. Parameters, such as volume flow rate, turbine clearance, turbine speed and number of turbine blades have been varied. The systematic observation of the distribution of velocities and power density help assess the ecological impact of those modifications. It is found that a moderate increase of the turbine clearance and a reduction of the number of blades provide an attractive compromise between power output and opportunity for easy migration. Finally, it is predicted that the hazard associated with a fish hitting turbine blades can be greatly reduced by a careful adaptation of the turbine rotation velocity. Those developments are a first step towards a systematic numerical assessment of the fish-friendliness of machines operating under stringent ecological regulations.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"34 1","pages":"86 - 98"},"PeriodicalIF":0.0,"publicationDate":"2018-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89488469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of river confinement on depth and spatial extent of bed disturbance affecting salmon redds","authors":"Christiana R. Czuba, J. Czuba, C. Magirl, A. Gendaszek, C. Konrad","doi":"10.1080/24705357.2018.1457986","DOIUrl":"https://doi.org/10.1080/24705357.2018.1457986","url":null,"abstract":"ABSTRACT Human impacts on rivers threaten the natural function of riverine ecosystems. This paper assesses how channel confinement affects the scour depth and spatial extent of bed disturbance and discusses the implications of these results for salmon-redd disturbance in gravel-bedded rivers. Two-dimensional hydrodynamic models of relatively confined and unconfined reaches of the Cedar River in Washington State, USA, were constructed with surveyed bathymetry and available airborne lidar data then calibrated and verified with field observations of water-surface elevation and streamflow velocity. Simulations showed greater water depths and velocities in the confined reach and greater areas of low-velocity inundation in the unconfined reach at high flows. Data on previously published scour depth of bed disturbance during high flows were compared to simulated bed shear stress to construct a probabilistic logistic-regression model of bed disturbance, which was applied to spatial patterns of simulated bed shear stress to quantify the extent of likely bed disturbance to the burial depth of sockeye and Chinook salmon redds. The disturbance depth was not observed to differ between confined and unconfined reaches; however, results indicated the spatial extent of disturbance to a given depth in the confined reach was roughly twice as large as in the unconfined reach.","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"45 1","pages":"17 - 4"},"PeriodicalIF":0.0,"publicationDate":"2018-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91324909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges of integrating habitat for aquatic life and morphodynamics offer a plethora of opportunities for advances in Ecohydraulics","authors":"C. Katopodis, P. Kemp","doi":"10.1080/24705357.2018.1484331","DOIUrl":"https://doi.org/10.1080/24705357.2018.1484331","url":null,"abstract":"Morphodynamics and aquatic biota (i.e. plants and animals) interact through complex processes, to generate suitable, diverse and resilient habitats. We define morphodynamics in broad terms as the discipline of Earth surface characteristics and evolution which integrates hydrological, geomorphological and geological aspects. This definition is similar, although narrower to that offered by Paola et al. (2006), since we include ecological and biological aspects in Ecohydraulics. Complex physical processes are linked to planforms, longitudinal profiles and cross-sectional geometries in rivers, lakes and deltas and involve the cycling of water, sediment, ice, nutrients, solutes and organic materials in watersheds. Through surface, subsurface or groundwater flow, erosion, transport, deposition and ice conditions, morphodynamics shapes bars, pools, riffles, islands, side channels and other features in waterbodies (Paola et al. 2006; Wohl et al. 2015). Ecological dynamics, commonly understood less clearly, represent the even more complex life processes and food webs, responses by aquatic species and vegetation, populations and communities, as well as suitable habitats characterized by spatial complexity, connectivity and dynamism which meet biota life cycle requirements, enable ecosystem functionality and support biodiversity (Elosegi et al. 2010). Large differences in genetic flow, dispersal and mobility strategies or abilities of aquatic biota populations add another layer to this complexity and needs for more in-depth knowledge and understanding. With such complexities, it is not surprising that large knowledge gaps exist in morphodynamics and ecology, and particularly in the interaction between the two. Although often it is thought that geomorphology sets the template for biological processes (e.g. Vannote et al. 1980), recent studies indicate direct and indirect effects on physical processes from aquatic and riparian vegetation, particularly in the riparian zone (e.g. Gurnell et al. 2012), or even from fish through nutrient enrichment or potential effects on gravel substrates (e.g. DeVries 2012). Such interactions create numerous feedback mechanisms between biotic and abiotic processes, ecology and morphodynamics, generate further knowledge gaps and offer potentially great insights if elucidated though comprehensive studies. Since Ecohydraulics is at the interface between morphoand eco-dynamics and explores biota and physical interactions, breakthroughs in this interdisciplinary field become very challenging. At the same time, such challenges offer a plethora of opportunities for pioneering research and practical applications for interand trans-disciplinary advances in Ecohydraulics. River systems have influenced people and their settlements since the dawn of civilization, while humans continue to alter, regulate and manage them to: (1) suppress floods and control water levels; (2) supply water for domestic use, agriculture, recreation and many indu","PeriodicalId":93201,"journal":{"name":"Journal of ecohydraulics","volume":"41 1","pages":"1 - 3"},"PeriodicalIF":0.0,"publicationDate":"2018-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77930121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}