6sterreichische Wasser- und Abfallwirtschaft / Die unbekannte dritte Dimension: Gel\ue4ndeh\uf6hen, Gew\ue4ssertiefen und Dynamik \uf6sterreichischer Donaulandschaften vor der Regulierung

Flusslandschaften sind multidimensionale, durch vielf\ue4ltige r\ue4umlich-zeitliche Wechselbeziehungen gepr\ue4gte 6kosysteme. Longitudinale Interaktionen entlang des Flusskontinuums sowie laterale Austauschprozesse zwischen Fluss und Augebiet stehen bei Restaurationsprojekten zumeist im Vordergrund. Vertikale Wechselwirkungen, wie zum Beispiel zwischen Wasserlebensraum und Flusssohle (hyporheisches Interstitial) oder zwischen Grundwasser und terrestrischen Habitaten, werden oft erst dann in die Planungen miteinbezogen, wenn die Beeintr\ue4chtigungen \uf6kologischer Funktionen und menschlicher Nutzungen bereits offensichtlich sind. Dies liegt zum Teil auch daran, dass f\ufcr die Zeit vor der Regulierung kaum fundierte Grundlagendaten \ufcber die Ausformung unserer Flusslandschaften in vertikaler Dimension vorliegen, an denen man sich bei Planungen orientieren k\uf6nnte. Ergebnisse mehrerer Forschungsprojekte aus den letzten Jahren gew\ue4hren neue Einblicke in die dreidimensionale hydromorphologische Auspr\ue4gung der \uf6sterreichischen Donaulandschaften zu Beginn und Mitte des 19. Jahrhunderts. Sie erlauben eine konkrete h\uf6henm\ue4 fige Einstufung verschiedener, \uf6komorphologisch relevanter Gel\ue4ndezonen innerhalb des Augebiets in Bezug zu charakteristischen Wasserst\ue4nden der Donau. Jede dieser Zonen entspricht einem bestimmten morphologischen Entwicklungsstadium und erf\ufcllt unterschiedliche \uf6kologische Funktionen. Rekonstruktionen der Flurabst\ue4nde innerhalb des neuzeitlichen, bis zu 500 Jahre alten Augebiets zeigen, dass diese bei Mittelwasser mit durchschnittlich rund 1,6\u20131,9 m relativ gering waren. Im Vergleich dazu liegen heute die Flurabst\ue4nde bei rund 3 m oder dar\ufcber. Der Wasserk\uf6rper der Donau war ehemals nicht nur viel breiter, sondern auch wesentlich flacher ausgebildet als heute. So nahmen bis zu einem Meter tiefe Flachwasserzonen bei sommerlichem Mittelwasser ehemals ca. 8,1 ha pro km Luftlinie ein, w\ue4hrend sie aktuell nur mehr bei 1,2 ha liegen. Dies entspricht einem R\ufcckgang um 86 %. Dabei ist noch nicht ber\ufccksichtigt, dass es ehemals auch zahlreiche durchstr\uf6mte Nebenarme mit vergleichbaren Habitaten gab, die heute nicht mehr existieren. Besonders interessante Einblicke ergeben sich bez\ufcglich der historischen Umlagerungsdynamik der Donau. Im Zuge von avulsiven Laufverk\ufcrzungen von Donauhauptarmen wurden zwischen 1812 und 1817 im Mittel j\ue4hrlich 3 Millionen m\ub3 an Material erodiert und 2,6 Millionen m\ub3 innerhalb desselben Augebiets wieder abgelagert. Rund 0,4 Millionen m\ub3 wurden durchschnittlich jedes Jahr aus dem System ausgetragen und weiter flussabw\ue4rts transportiert. Eine derart intensive Umlagerungsdynamik ereignete sich jedoch innerhalb eines bestimmten Flussabschnitts nicht permanent. In den Folgejahren reduzierten sich die erodierten Volumina erheblich, w\ue4hrend die Ablagerungen leicht \ufcberwogen. Die intensive morphologische Dynamik spiegelte sich auch in signifikanten Absenkungen und Hebungen der Wasser- bzw. Grundwasserspiegellagen innerhalb des Augebiets wider. Trotz der umfassenden Ver\ue4nderungen der Flusslandschaft blieben diese in Summe jedoch ann\ue4hernd ausgeglichen. Auch andere untersuchte Parameter deuten darauf hin, dass sich die hydromorphologische Ausformung von Aulandschaften \ufcber gr\uf6 fere Fl\ue4chen und l\ue4ngerfristig betrachtet in einem dynamischen Gleichgewicht oder quasistation\ue4ren Zustand (\u201esteady state\u201c) befanden. Nicht nur an der Donau, sondern entlang der meisten gr\uf6 feren Fl\ufcsse haben die Augebiete heute wesentlich h\uf6here Gel\ue4ndelagen in Relation zum Wasser- bzw. Grundwasserspiegel, als dies vor der Regulierung der Fall war. Eintiefung der Flusssohle einerseits und durch Ablagerung von Sedimenten bei Hochw\ue4ssern stetig auflandende Augebiete andererseits f\ufchren zu einer immer st\ue4rkeren vertikalen Entkoppelung der Wasser- und Landlebensr\ue4ume in Fluss-Auen-Systemen. Die Flurabst\ue4nde vergr\uf6 fern sich und die ehemals nassen, feuchten oder frischen Standorte der Weichen Au gehen sukzessive verloren. Die dargestellten Beispiele aus der Geschichte der \uf6sterreichischen Donau zeigen, dass eine flusstypische \u2013 und im Falle der Donau hohe \u2013 Umlagerungsintensit\ue4t, durch die gro fe Anteile der aquatischen und terrestrischen Habitate in vergleichsweise kurzen Zeitr\ue4umen regeneriert und verj\ufcngt wurden, als Schl\ufcssel zur Aufrechterhaltung eines heterogenen Habitatkomplexes anzusehen ist.River landscapes are multidimensional ecosystems characterized by diverse spatio-temporal interrelations. Longitudinal interactions along the river continuum and lateral exchange processes between river and floodplain are common focal points in river restoration projects. Vertical interactions, such as between aquatic habitats and river bottom (hyporheic interstitial) or between groundwater and terrestrial habitats, are often only addressed in planning schemes, if the impairments of ecological functions and human uses are already evident. This partly reflects the dearth of well-founded basic data on the configuration of river landscapes prior to regulation in the vertical dimension. Consequently, only few reference data are available for designing adapted restoration measures. Several research projects in recent years have yielded new insights into the three-dimensional hydromorphological configuration of Austrian Danube landscapes in the early and mid-19th century. They enable the height of different ecomorphologically significant terrain zones within the floodplain to be specified in respect to characteristic Danube water levels. Each of these zones corresponds to a particular morphological stage of development and fulfills specific ecological functions. Reconstructions of the groundwater tables at mean water level within the modern, up to 500-years-old floodplain show that these were on average only 1.6-1.9 m below the terrain surface. In comparison, today the groundwater table depths amount to c. 3 m or more. The water bodies of the Danube were formerly not only much broader, but also much shallower. Accordingly, shallow, up to 1\u2011meter-deep water zones originally amounted to c. 8.1 ha per km linear distance at summer mean water level. In contrast, the current value is 1.2 ha, representing an 86 % decrease. This calculation omits the formerly numerous lotic side arms with comparable habitats that no longer exist today. Particularly interesting insights were obtained regarding the historical morphological dynamics of the Danube. In the course of avulsive shortenings of Danube main arms, an average 3 million m\ub3 of sediments were eroded annually between 1812 and 1817, and 2.6 million m\ub3 were redeposited in the same floodplain. About 0.4 million m\ub3 were discharged each year from the system and transported further downstream. Importantly, such massive turnover processes did not occur permanently within a particular river section. In subsequent years, the eroded volumes dropped significantly, with deposition clearly exceeding erosion. The intensive morphological dynamics were reflected in significant drawdowns and uplifts of the water and groundwater levels within the floodplain. Despite the extensive changes in the river landscape, in total these hydrodynamics remained roughly balanced. Other examined parameters indicate that \u2013 viewed over larger areas and longer time periods \u2013 the hydromorphological configuration of the river landscape remained in dynamic equilibrium or a type of steady state. Today, along the Danube River and most other major rivers, floodplains show much higher terrain levels in relation to the water or groundwater level than prior to regulation. Riverbed deepening, combined with constantly increasing levels of the floodplain terrain due to flood-related sediment deposition, led to a progressing vertical decoupling of aquatic and terrestrial habitats in the river-floodplain systems. Depths of the groundwater table relative to the terrain surface increased and formerly wet, moist or fresh sites of softwood forests were successively lost. The examples from the history of the Austrian Danube River illustrate that a river-typical \u2013 and in the case of the Danube River high \u2013 intensity of fluvial dynamics is crucial in maintaining a heterogeneous habitat complex. These processes regenerate and rejuvenate large parts of the aquatic and terrestrial habitats in relatively short periods of time

How water and its use shaped the spatial development of Vienna

Telling an environmental history of Vienna’s urban waters, this paper advocates the compound study of the evolution of fluvial and urban form. It traces the structural permanence of diverse types of running waters in a period of massive urban transformation from early modern times to present. The focus on the material effects, side-effects and afterlives of socio-natural processes offers novel perspectives to the reconstruction of city development. The featured cases show that long-term studies are vital in understanding the genesis of urban water bodies and urban form as a product of socio-natural processes. They inform us about the inertia of arrangements and the unforeseen perpetuation of site-specific effects of interventions. Societal interaction with natural elements such as Vienna’s waters, we conclude, reverberates in the material and immaterial realm alike

A Conceptual Model of Vegetation-hydrogeomorphology Interactions Within River Corridors

This is the peer reviewed version of the following article: M. GURNELL, D. CORENBLITc, D. GARCÍA DE JALÓN, M. GONZÁLEZ DEL TÁNAGO, R. C. GRABOWSKI, M. T. O’HARE, M. SZEWCZYK (2015) A conceptual model of vegetationhydrogeomorphology interactions within river corridors. River Research and Applications (early view), which has been published in final form at 10.1002/rra.2928. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.European Union. Grant Number: no. 28265

Urban land for a growing city at the banks of a moving river: Vienna's spread into the Danube island Unterer Werd from the late 17th to the beginning of the 20th century

In the relation between urban development and the Viennese Danube different periods can be identified from the late 17th to the early 20th century. These periods were strongly intertwined with both the history of the river and the history of the city. Urban expansion into the floodplains is demonstrated in this paper by investigating the island Unterer Werd, next to the city centre. In the late 17th century the fluvial dynamic still hampered urban development on the island. First measures to stabilise the river banks and to protect buildings from floods were taken soon thereafter, but the majority of practices aimed at mitigating the risks and impacts of the frequent floods: inundation was a part of the arrangement and the main target was to minimise the potential impacts. This practice also prevailed after the 1830s, when urban expansion began to move into the north and northwest of the island and the Danube floodplains were considered an important land resource for the growing city. In connection with new technologies and available means to channelise the river, the relationship between Vienna and the Danube changed fundamentally. Urban development in the riverine landscape gained new momentum. This process was initiated before the Great Danube Regulation from 1870 to 1875 was completed, the rate of growth accelerated after 1875. The last decades of the 19th century mark a turning point in the urban development of Vienna, with expanding urban areas becoming dependent upon a well functioning and maintained flood protection system

The Vjosa River corridor: a model of natural hydro-morphodynamics and a hotspot of highly threatened ecosystems of European significance

Context: Large near-natural rivers have become rare in Europe, a fact reflected in the high conservation status of many riverine ecosystems. While the Balkan still harbors several intact river corridors, most of these are under pressure from planned hydropower constructions. Unfortunately, there is little information available on the hydromorphodynamics and biota of Balkan rivers under threat. Objectives: We present a synthesis of research on the Vjosa in Southern Albania. Here, longitudinal continuity in water flow, undisturbed sediment transport and intact fluvial dynamics are still maintained, but threatened by two large dams planned in its downstream section. We intend to provide a first multidisciplinary inventory of this river system as an example of the knowledge base required for sound water management decisions in the Balkans. Methods: Based on field work of a multidisciplinary consortium of scientists from Albania and other countries conducted from 2017 onwards, we summarize the most important findings on geomorphology of the riverine landscape, habitat turnover rates, vegetation ecology and selected animal taxa. Results: We found evidence that significant areas (86%) of the river corridor are covered by habitats listed in Annex 1 of the European Union Habitats Directive. These are associated with a high number of threatened biota. Conclusions: Our findings underscore the value of the Vjosa as one of the few remaining reference sites for dynamic floodplains in Europe and as a natural laboratory for interdisciplinary research. We emphasize that such multidisciplinary studies are a prerequisite for informed evaluation of potential impacts caused by hydropower plants

Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis

The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses

Inhibition of microRNA-494-3p activates Wnt signaling and reduces proinflammatory macrophage polarization in atherosclerosis

We have previously shown that treatment with third-generation antisense oligonucleotides against miR-494-3p (3GA-494) reduces atherosclerotic plaque progression and stabilizes lesions, both in early and established plaques, with reduced macro-phage content in established plaques. Within the plaque, different subtypes of macrophages are present. Here, we aimed to investigate whether miR-494-3p directly influences macrophage polarization and activation. Human macrophages were polarized into either proinflammatory M1 or anti-inflammatory M2 macrophages and simultaneously treated with 3GA-494 or a control antisense (3GA-ctrl). We show that 3GA-494 treatment inhibited miR-494-3p in M1 macrophages and dampened Ml polarization, while in M2 macrophages miR-494-3p expression was induced and M2 polarization enhanced. The proinflammatory marker CCR2 was reduced in 3GA-494-treated atherosclerosis-prone mice. Pathway enrichment analysis predicted an overlap between miR-494-3p target genes in macrophage polarization and Wnt signaling. We demonstrate that miR-494-3p regulates expression levels of multiple Wnt signaling components, such as LRP6 and TBL1X. Wnt signaling appears activated upon treatment with 3GA-494, both in cultured M1 macrophages and in plaques of hypercholesterolemic mice. Taken together, 3GA-494 treatment dampened M1 polarization, at least in part via activated Wnt signaling, while M2 polarization was enhanced, which is both favorable in reducing atherosclerotic plaque formation and increasing plaque stability.Vascular Surger

River histories : A thematic review

Peer reviewe

Six decades of changes in the riparian corridor of a Mediterranean river: A synthetic analysis based on historical data sources

Riparian corridors in semi-arid Mediterranean environments are ecosystems of high biodiversity and complexity. However, they are threatened because of high levels of human intervention. River damming and related flow manipulation is considered as one of the most prominent human impacts on riparian corridors. This study combines historical time series information on river flows and their human manipulation, historical aerial images depicting changes in riparian land cover and ground observations of the species - age composition and morphology of the riparian corridor of a Mediterranean river (the Mijares River, Eastern Spain) over the last 60years. In this sense, we explored how to integrate information from a wide variety of data sources, and we extracted a variety of indices and undertook analyses that identified and summarized spatio-temporal changes in riparian structure and in the driving flow processes. Results revealed an increase in the cover and density of woody vegetation and a decrease in bare sediment areas (essential for recruitment of riparian pioneer species), with a synchronous reduction in the complexity of the riparian corridor of the middle reaches of the Mijares River. These vegetation changes have accompanied a decrease in the magnitude and variability of river flows over the last six decades, with higher severity since dam closure. This study illustrates the effectiveness of combining disparate historical data sources and the effectiveness of processing these sources to extract informative metrics that can improve the understanding and management of riparian systems. © 2012 John Wiley & Sons, Ltd.The authors are grateful to Paula De Lamo (who worked in an early version of this study), Carlos Gonzalez-Hidalgo (who gave us access to the MOPREDAS database) and Alicia Garcia-Arias and Oscar Belmar (for their support in the calculation of confusion matrices and in the flow regime analysis, respectively). We also thank Confederacion Hidrografica del Jucar (Spanish Ministry of Agriculture, Food and Environment) and the professors Juan Marco Segura and Javier Paredes for the hydrological data provided to develop this study. TECNOMA S. A. provided logistic support. Finally, we acknowledge the Universitat Politecnica de Valencia for the two grants of the Support Programme for Research and Development 'Programa de Apoyo a la Investigacion y Desarrollo' (PAID 00-10 and 00-11). This study was partially funded by the Spanish Ministry of Economy and Competitiveness with the projects 'Recent environmental changes in fluvial systems: morphological and sedimentological consequences' (CGL2009-14220-C02-02-BTE) and SCARCE (Consolider-Ingenio 2010 CSD2009-00065). The feedback of two anonymous reviewers has been very helpful and is greatly appreciated.Garófano-Gómez, V.; Martinez-Capel, F.; Bertoldi, W.; Gurnell, Á.; Estornell Cremades, J.; Segura-Beltrán, F. (2012). Six decades of changes in the riparian corridor of a Mediterranean river: A synthetic analysis based on historical data sources. Ecohydrology. 0:0-0. https://doi.org/10.1002/eco.1330S00

Characterizing geomorphological change to support sustainable river restoration and management

The hydrology and geomorphology of most rivers has been fundamentally altered through a long history of human interventions including modification of river channels, floodplains, and wider changes in the landscape that affect water and sediment delivery to the river. Resultant alterations in fluvial forms and processes have negatively impacted river ecology via the loss of physical habitat, disruption to the longitudinal continuity of the river, and lateral disconnection between aquatic, wetland, and terrestrial ecosystems. Through a characterization of geomorphological change, it is possible to peel back the layers of time to investigate how and why a river has changed. Process rates can be assessed, the historical condition of rivers can be determined, the trajectories of past changes can be reconstructed, and the role of specific human interventions in these geomorphological changes can be assessed. To achieve this, hydrological, geomorphological, and riparian vegetation characteristics are investigated within a hierarchy of spatial scales using a range of data sources. A temporal analysis of fluvial geomorphology supports process-based management that targets underlying problems. In this way, effective, sustainable management and restoration solutions can be developed that recognize the underlying drivers of geomorphological change, the constraints imposed on current fluvial processes, and the possible evolutionary trajectories and timelines of change under different future management scenarios. Catchment/river basin planning, natural flood risk management, the identification and appraisal of pressures, and the assessment of restoration needs and objectives would all benefit from a thorough temporal analysis of fluvial geomorphology