Papers by Bernhard Zeiringer
River Research and Applications
Supplementary Files: A Physical and Behavioral Barrier for Enhancing Fish Downstream Migration at... more Supplementary Files: A Physical and Behavioral Barrier for Enhancing Fish Downstream Migration at Hydropower Dams: The Flexible FishProtector
EGU General Assembly Conference Abstracts, Apr 1, 2019
The Science of the total environment, 2017
High-head storage hydropower is deemed to be the ideal renewable energy source in Alpine regions ... more High-head storage hydropower is deemed to be the ideal renewable energy source in Alpine regions to meet the increasing demand for daily peak electrical energy. However, this mode of operation - called hydropeaking - can imply severe hydrological and hydromorphological consequences for river ecosystems, affecting fish populations by e.g. drift and stranding of young life stages. Several fish-stranding experiments using physical models have been performed in the past, but until now very little is known about influences of time of day or gravel bank heterogeneity. We performed experiments during late summer 2013 with juvenile European grayling (Thymallus thymallus) (mean length: 53mm) in a nature-like experimental channel enabling hydropeaking simulations. In the first experiments (n=21) we observed relative drift and stranding rates for a single hydropeaking event focusing on the effect of time of day on a homogenous gravel bank. The second test series (n=15) focused on two dewaterin...
Hydrological Processes, 2016
Hydro peaking causes an important environmental impact on running water ecosystems. Many affected... more Hydro peaking causes an important environmental impact on running water ecosystems. Many affected rivers have a poor ecological status. In rivers affected by hydro peaking, the flow conditions are highly complex and difficult to grasp. To develop a general framework for detecting and characterizing sub-daily flow fluctuations, we analysed more than 500 Austrian hydrographs, covering the whole range from unimpacted to heavily impacted rivers. Different fluctuation types could be identified according to the potential source: e.g. sub-daily flow fluctuations caused by hydro peaking, rainfall or snow and glacier melt. Additionally, the term 'hydro fibrillation' was established, to indicate frequently occurring artificial fluctuations with comparably low intensities. An automatic procedure was used to detect frequency and intensity of each flow fluctuation. Using variables based on duration curves of flow fluctuation rates (ramping rates), amplitudes, flow ratios, durations and daily numbers of fluctuations, a predictive model (linear discriminant analysis) was fitted to classify hydrographs into predominant fluctuation regimes. This is the basis for a detailed investigation of present sub-daily flow regimes and to analyse the differences between the regimes. Based on the results, we finally propose a general framework that enables a standardized assessment of flow fluctuations regarding event intensities and/or event timing. The proposed framework offers a standardized selection of particular flow fluctuations referring to increase and decrease events separately. The selection of specific flow fluctuations can be defined with respect to several research questions (e.g. ecologically relevant fluctuations), which offers a wide range of applications.
Österreichische Wasser- und Abfallwirtschaft, 2015
Zusammenfassung Wasserkraftanlagen verzögern bzw. verhindern Wanderungen von Fischen. Während die... more Zusammenfassung Wasserkraftanlagen verzögern bzw. verhindern Wanderungen von Fischen. Während die Errichtung von Fischaufstiegshilfen (FAH) mittlerweile als Stand der Technik vorgeschrieben ist und für Österreich auch ein entsprechender Leitfaden zum Bau von Fischaufstiegshilfen (BMFLUW 2012) erschienen ist, liegen Lösungsansätze hinsichtlich der Problematik des Fischabstieges aufgrund von Wissensdefiziten noch nicht in vergleichbarer Form vor. Folgender Beitrag soll einen Überblick über bisherige Erkenntnisse hinsichtlich flussab gerichteter Wanderungen heimischer, potamodromer Fischarten sowie über verschiedene technische Lösungsmöglichkeiten, deren Anforderungen und Anwendungsgrenzen für den Einsatz an Wasserkraftanlagen liefern. Darüber hinaus werden aktuell laufende, nationale Forschungsprojekte zu dieser Thematik vorstellt. Fish protection and downstream migration: current state of knowledge and research projects in Austria Abstract Hydropower plants delay or prevent fish migration. While the construction of fish passes for upstream migration is now compulsory, and guidelines for building upstream fishways (BMFLUW 2012) in Austria have been published, efficient solutions for downstream migration are much less advanced. This article summarizes our current understanding of the downstream migration of native potamodromous fish species, and of the requirements and application-related limitations of various technical solutions. Furthermore it highlights current national research projects in this area.
Proceedings of the 39th IAHR World Congress
Water
Fish protection at hydropower plants is important for the sustainability of hosting ecosystems an... more Fish protection at hydropower plants is important for the sustainability of hosting ecosystems and the acceptance of hydropower. On their way downstream, fish are exposed to hydropower plants and various related negative effects, ranging from a delay in downstream movement to being injured or killed by a turbine. Understanding the behavior of fish in close proximity to protection devices is essential in order to establish efficient fish protection facilities. In this study, physical (horizontal steel cables) and behavioral barriers (electric field) for fish protection were developed (Flexible FishProtector) and their effectiveness was investigated. The behavior of brown trout (Salmo trutta fario), rainbow trout (Oncorhynchus mykiss), grayling (Thymallus thymallus) and chub (Squalius cephalus) at the Flexible FishProtector was analyzed using video evaluation. The experimental setup was a non-scaled section model of a runoff river power plant. The used electric field induced a flight ...
Rivers have all too often been considered as two-dimensional elements of terrestrial landscapes n... more Rivers have all too often been considered as two-dimensional elements of terrestrial landscapes neglecting their own internal structure and heterogeneity. But rivers exhibit certain characteristics, which should grant them a special position in connectivity conservation. With habitat fragmentation causing dramatic losses in global aquatic biodiversity, ecological research put much effort into conservation measures for maintaining and restoring connectivity of riverine habitats. To make use of the full mitigation hierarchy, the implementation of both avoidance (e.g. large-scale planning) and mitigation measures (e.g. facilities for up- and downstream migration) should be aspired.
Ispitivanje učinkovitosti i ocjena hidroelektrane s dvojnim rotirajućim hidroenergetskim pužnim s... more Ispitivanje učinkovitosti i ocjena hidroelektrane s dvojnim rotirajućim hidroenergetskim pužnim sustavom Novorazvijeni koncept Arhimedovog dvostrukog hidroenergetskog pužnog sustava u jednom uređaju objedinjuje proizvodnju električne energije i dvosmjerni sustav za prolazak riba. Na prvom komercijalnom projektu provedena su ispitivanja učinkovitosti kako bi se provjerili podaci dobiveni tijekom projektiranja. Otprije je poznata mogućnost nizvodnog propuštanja. Međutim, u okviru ovog istraživanja dokazana je i stvarna mogućnost uzvodnog propuštanja. Također je utvrđena i hidroenergetska učinkovitost postrojenja ove vrste. Prvi je puta dokazana hidraulička učinkovitost ovog uređaja.
Riverine Ecosystem Management
The water runs the river." This chapter focuses on the river flow as the fundamental process dete... more The water runs the river." This chapter focuses on the river flow as the fundamental process determining the size, shape, structure, and dynamics of riverine ecosystems. We briefly introduce hydrological regimes as key characteristics of river flow. Hydrological regimes are then linked to habitats and biotic communities. The effects of flow regulation as a result of human activities such as water abstraction (irrigation and hydropower), river channelization, land use, and climate change are demonstrated. Finally, methods to assess the environmental flow, the flow that is needed to maintain the ecological integrity, are described, and examples of successful flow restoration presented. 4.1 The Water Cycle and Hydrological Regimes In temperate zones water received via precipitation is either stored in ice and snow during winter or infiltrates into the groundwater and is released into rivers during summer. Water cycles through stages of evaporation, water storage in the atmosphere, precipitation, (sub)surface runoff, and storage in the ocean. The water cycle and climatic conditions form the boundary conditions for the hydrological regimes that define distinct seasonal and daily flow patterns. High altitude rivers receive water mainly from glacial melt during summer with distinct diurnal melting peaks following air temperature warm-up (glacial regime) (Fig. 4.1). At lower elevations snow melting in spring causes seasonal peaks (nival regime), while periods of high flow and floods due to rainfall can occur at any time of the year (pluvial regime).
Journal of Environmental Management
Riverine Ecosystem Management, 2018
Flow is a major driver of processes shaping physical habitat in streams and a major determinant o... more Flow is a major driver of processes shaping physical habitat in streams and a major determinant of biotic composition. Flow fluctuations play an important role in the survival and reproductive potential of aquatic organisms as they have evolved life history strategies primarily in direct response to natural flow regimes (Poff et al. 1997; Bunn and Arthington 2002). However, although the organisms are generally adapted to natural dynamics in discharge, naturally caused flow fluctuations may entail negative consequences (e.g., stranding, drift, low productivity), especially if the intensity is exceptionally high or the event timing is unusual (Unfer et al. 2011; Nagrodski et al. 2012). Aside from natural dynamics in discharge, artificial flow fluctuations with harmful impacts on aquatic ecology can be induced by human activities. Hydropeaking-the discontinuous release of turbined water due to peaks of energy demand-causes artificial flow fluctuations downstream of reservoirs.
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Papers by Bernhard Zeiringer