Advertisement

The Role of Sediment and Sediment Dynamics in the Aquatic Environment

  • Christoph Hauer
  • Patrick Leitner
  • Günther Unfer
  • Ulrich Pulg
  • Helmut Habersack
  • Wolfram Graf
Open Access
Chapter
Part of the Aquatic Ecology Series book series (AQEC, volume 8)

Abstract

The dynamic component in hydrology, sedimentology, and, consequently, river morphology serves as a backbone for the entire river environment (Maddock 1999). In addition to water pollution, the hydro-morphological/sedimentological degradation is one of the main pressures on river systems (Ward and Stanford 1995; Dudgeon et al. 2006). The EU Water Framework Directive (WFD, Directive 2000/60/EC) mentions various aspects of hydro-morphological disturbances that must be addressed by management plans to achieve the aims of a good ecological status or a good ecological potential (Article 3/Article 4). However, to reach these goals, the sediment conditions of a river (e.g., sediment continuum) are not part of the evaluation needs. Here, to achieve “good ecological status,” it is assumed that the biotic criteria reflect the hydro-morphological status, while direct assessments of dynamic sedimentological processes are not taken into account (Hauer 2015).

8.1 Introduction

The dynamic component in hydrology, sedimentology, and, consequently, river morphology serves as a backbone for the entire river environment (Maddock 1999). In addition to water pollution, the hydro-morphological/sedimentological degradation is one of the main pressures on river systems (Ward and Stanford 1995; Dudgeon et al. 2006). The EU Water Framework Directive (WFD, Directive 2000/60/EC) mentions various aspects of hydro-morphological disturbances that must be addressed by management plans to achieve the aims of a good ecological status or a good ecological potential (Article 3/Article 4). However, to reach these goals, the sediment conditions of a river (e.g., sediment continuum) are not part of the evaluation needs. Here, to achieve “good ecological status,” it is assumed that the biotic criteria reflect the hydro-morphological status, while direct assessments of dynamic sedimentological processes are not taken into account (Hauer 2015).

In general, sediments play a decisive role for diversification and composition and, hence, the quality of habitats, especially for the mid- to long-term development of habitat features. According to Leopold et al. (1964), there are eight factors forming the morphological traits of a river: channel width, depth, flow velocity, discharge, channel slope, roughness of channel material, sediment load, and sediment size. Disturbances in any of those factors can alter the general habitat composition of the river and consequently the morphological type of a river. Sediments are both habitat forming (e.g., boulders) and part of morphological structures (e.g., gavel at gravel bars) (Hauer et al. 2014).

Concerning possible impacts of sediment disturbances on the aquatic biota, both the time scale and the form of impact (direct or indirect) are decisive. On the one hand, mid- to long-term indirect impacts are evident due to changes of the physical environment (e.g., changes in sedimentology, loss of spawning sites) as well as short-term, direct (highly dynamic) impacts due to physiological stress (e.g., high turbidity for fish) or risk of abrasion (e.g., for macroinvertebrates). Especially, catchment or reach-scale sedimentological and hydro-morphological disturbances may change the channel shape and/or the habitat composition in the mid- to long-term. Disturbances of the sediment regime are always related to deficits or surpluses in sediment supply and sediment transport (e.g., Brooks and Brierley 1997; Sutherland et al. 2002) which are presented in this book chapter.

Specifically, in alpine regions, the impact of sediment deficits is responsible for riverbed incision and related habitat degradation (Habersack and Piégay 2008). At the same time, increase in sediment load and transport is hardly found in alpine regions but is a major problem in regions with soil erosion due to intensive agriculture or forestry (Leitner et al. 2015; Höfler et al. 2016). Man-made reductions in the sediment load due to torrent controls or retention by hydropower use may have two different consequences, sometimes occurring simultaneously in one and the same river. On one hand, depending on the frequency of floods, the coarsening of substrate due to selective transport leads to fluvial armor or pavement layers (Sutherland 1987). On the other hand, in alpine basins with fine material deposits from the tertiary (marine sediments) below the quaternary gravel layer of the riverbed, the risk of a so-called riverbed breakthrough (Habersack and Klösch 2012) may be realized due to a single flood (e.g., the Salzach River in 2002; Hopf 2006). Another increasingly frequent problem connected to sediment retention is the flushing of reservoirs (see also Chap.  6). During flushing, large amounts of retained suspended load are released in a short period of time, mostly in conjunction with flood events resulting in a surplus of sediments in downstream river sections. Consequently, high loads of mostly fine sediments cause high concentrations of turbidity and can be responsible for losses and mortality of aquatic organisms (e.g., Espa et al. 2015).

Consequences of sediment deficits and impacts on the river are (1) decrease in habitat heterogeneity (Kondolf 1997); (2) risk of river bank erosion (Rinaldi and Casagli 1999); (3) risk of damage to infrastructure, e.g., scouring bridge piers (Jäger et al. 2018); (4) lack of spawning habitats for salmonid fish species (Hauer et al. 2013) and depauperate macroinvertebrate fauna (Graf et al. 2016); (5) decrease in sediment turnover rates and river type-specific sediment quality (Kondolf 1997); and (6) risk of channel avulsion during extreme events (Brizga and Finlayson 1990). Channel avulsion refers to abrupt changes of the river course leading to a new active channel in the former floodplain.

The aim of this book chapter is to give an overview of the role of sediment and sediment dynamics for the aquatic environment with a special focus on alpine rivers and their fish fauna. We describe how sediment dynamics determine river morphology and habitat-forming processes. Moreover, problems of human-induced sediment increase (e.g., reservoir flushings, intensive agricultural and forestry land use leading to intrusion of fine sediments) and deficits (e.g., deposition by torrent controls and hydropower plants) are targeted with respect to the biotic requirements of macroinvertebrates and fish.

8.2 Sediments and River Morphology

Depending on the morphological river type (Montgomery and Buffington 1997), single grain sizes can be hydraulically habitat forming (e.g., cascade or step-pool type) or just components of a morphological feature (e.g., a gravel bar) that determine the hydraulic patterns of a river (e.g., riffle—pool type) (Hauer et al. 2014). As a decisive variable for channel- and habitat-forming processes, the role of sediments is described in the following subchapters according to their importance in morphological classification, sources in and along river corridors considering river scaling aspects.

8.2.1 River Morphology and Substrate Size

The substrate size and variability in substrate resistance according to the stream power are important agents controlling river morphology (according to Leopold et al. 1964). In this chapter, in contrast to the description of the morphological classification presented in Chap.  3, we use the more sediment size-based classification of Montgomery and Buffington (1997). Here, five different river types for alpine rivers can be distinguished with differences in sediment composition, sediment dynamics, and habitat features:
  1. 1.

    The cascade type is characterized by irregular boulders, local pools, and a large range of particle sizes. Energy dissipation is dominated by continuous tumbling and jet-and-wake flow around and over individual, large clasts (Peterson and Mohanty 1960). The large bedforming material of cascade reaches is immobile during typical flows. Large amounts of bedforming material are mobilized in cascade reaches only during infrequent, hydrologically extreme events with recurrence intervals of 50 up to >200 years (Grant et al. 1990; Phillips 2002). Locally stored gravel and finer grains on the lee sides of flow obstructions (e.g., boulders) are typical sedimentological characteristics of cascade reaches (Montgomery and Buffington 1997). Gravel bed spawning grounds are often small and patchy.

     
  2. 2.

    Step-pool morphology is characterized by downstream alterations of steps (clasts, wood, and/or bedrock) and plunge pools that develop downstream of each step (Chin 1999; Wohl 2013). Step-pool reaches are most commonly situated along river sections where relatively immobile clasts of coarse sediment can additionally trap wood (Wohl 2013). Energy dissipation is distributed stepwise with high levels at the steps and low dissipation at the outlet of the plunge pools. It is often these outlets which offer good spawning hydraulics and sediment conditions for salmonids. According to Whittaker (1987), step-pool channels reflect a sediment supply-limited system. Potential control variables (reach-scale gradient, discharge, sediment supply and size) for step-pool morphologies have been frequently investigated (e.g., Maxwell and Papanicolaou 2001). Here, in alluvial step-pool systems, particle size was found to determine the step height and discharge as the dominant factor determining the step wavelength (Chartrand and Whiting 2000).

     
  3. 3.

    Plane-bed reaches are characterized by a lack of gravel bars (e.g., point bars or mid-channel bars), which occur due to a low width-to-depth ratio and a large value of relative roughness (i.e., the ratio of the d90 percentile to bank-full depth) (Montgomery and Buffington 1997). Plane-bed channels tend to be intermediate between step-pool and pool-riffle channels regarding gradient slope and grain size (e.g., d90) (Wohl and Merrit 2008). Moreover, the characteristics of plane-bed channels typically in combination with an armored bed surface indicate a transport capacity larger than the sediment supply (Montgomery and Buffington 1997). Hence, supply-limited conditions are found for most discharges (Wohl and Merrit 2008) with some exceptions for high flows (e.g., Sidle 1988). Therefore, a lack of upstream bed-load supply (gravel-to-cobble sized sediments) may be responsible for the development of this specific morphological type. Larger gravel bed spawning grounds are rare and patchily distributed.

     
  4. 4.

    Riffle-pool channels occur at moderate-to-low gradients and are generally unconfined by valley margins or lateral obstructions (Montgomery and Buffington 1997), with a pool spacing of five to seven times the channel width (Keller and Melhorn 1978). In near-natural river systems, riffle-pool channels contain woody debris leading to forced pool formation with irregular distributions of these local depressions (Lisle 1986). Upstream sediment supply and transport rates cause variable changes in the storage capacity and changes in the channel configuration in low gradient riffle-pool channels (Schumm 1977). High-quality spawning sites for salmonid fish (e.g., brown trout) are usually not limited, especially in the transition zone downstream of the pool and upstream of the riffle crest (Hauer et al. 2013).

     
  5. 5.

    The low gradient dune-ripple type is associated with sand-bed channels (Montgomery and Buffington 1997). One of the main differences from the plane-bed, riffle-pool, step-pool, and cascade morphological types is that dune-ripple channels exhibit wandering bedforms (Henderson 1963) which are mobile during most water stages. For dune-ripple reaches, bed-load transport occurs even under low flow conditions, caused by the low critical mean flow velocity for the initiation of motion of the fine material predominately consisting of weathered granite and gneiss [according to Hjülström (1935)]. The occurrence of the dune-ripple type, which is classified as transport limited, is shaped by a high intake of fine sediments from tributaries. Such rivers usually provide poor spawning conditions for gravel-spawning fish species.

     

8.2.2 Sediment Sources

The sources of sediment are not addressed in the classification of river types and whether these sources are self-formed or relict. Self-formed and relict-non-fluvial streams can be difficult to distinguish in the field. For relict-non-fluvial stream, the off-river sediment supply is low or sediment input only occurs sporadically (Bunte and Abt 2001). In self-formed rivers, however, sediment sources are related entirely to on-site bed material, bank erosion, and upstream fluvial sediments (Andrews 1984). If the sediment sources are not coupled to hillslopes or other partially non-fluvial sources, streams are classified as uncoupled streams (e.g., Trainor and Church 2003). In contrast, coupled streams are determined by sediment supply from relict-fluvial and non-fluvial sources (e.g., Harvey 2001).

8.2.3 Scaling of Sediment Dynamics in the River Environment

Various concepts for scaling river morphology and instream habitats have been developed (e.g., Frisell et al. 1996; Habersack 2000; Maritan et al. 1996; Newson and Newson 2000). From an ecological point of view, the strong dependence of aquatic organisms on abiotic changes in the environment (e.g., sediment turnover, flow fluctuations) has to be emphasized (Hauer 2015). Changes in sediment composition and quantity directly impact aquatic life on various scales. For example, excessive sediment transport rates may change the morphological river type on the reach scale. Consequently, a switch from a riffle-pool morphology to a dune-ripple type can appear due to excessive supply of coarse sand based on impacts of climate change and intensified land use (Hauer 2015). Moreover, the morphological features on the meso-unit scale (decrease in depth variance) as well as the habitat quality at the on-site micro-unit scale can alter. Such local-scale phenomena as, e.g., the loss of interstitial volume and morphological heterogeneity impact macroinvertebrates (Crosa et al. 2010), fish (Pulg et al. 2013; Hauer et al. 2013; Sutherland et al. 2002), and, especially, mussel habitats (Geist and Auerswald 2007). All taxa are strongly influenced by sediment supply at both reach and catchment scales. Therefore, local-scale investigations and research might neglect important aspects of habitat degradation or fail to consider the mid- to long-term evolution and dynamics when mitigation measures are elaborated without considering the driving sedimentological processes at the reach and catchment scales (e.g., reduced sediment supply due to hydropower) (Hauer 2015).

Changes (natural or anthropogenic) of the sediment dynamics on the catchment scale may lead to large-scale disturbances as, e.g., changes in the “sedimentary-link” concept with far-reaching consequences on the instream sediment quality. The sedimentary link concept describes the form of lateral sediment supply from tributaries and its impact on the longitudinal distribution of grain size (Rice and Church 1998). In alpine landscapes, the concept describes the increase in the amount of bed load combined with an increase in the grain size diameter at tributaries followed by a regular downstream fining (Rice 1998; Rice and Church 1998). Unlike alpine river catchments where sediment input from tributaries leads to an increase in the sediment caliber, the “revised” sedimentary link concept for rivers with high sediment input posits a partial decrease in the sediment caliber at tributaries due to the increased deposition of fines (Hauer 2015).

8.3 Sediment Dynamics and Anthropogenic Alterations of the Sediment Flux: What Aquatic Biota Need and How They React to Alterations

Too Little: The Consequences of Sediment Deficits

Rivers exhibiting naturally (downstream of lakes) or anthropogenically reduced sediment supply are “supply-limited” rivers (Montgomery and Buffington 1997). Limited supply leads to continuous armoring of bed surface sediments, a process occurring during ordinary flood events and without extraordinary floods (Fig. 8.1a). In addition to natural bed armoring, human activities can reduce gravel supply and therefore lead to armors. For instance, dams and weirs are responsible for interruptions of the sediment continuum. Further bank stabilization measures reduce lateral sediment supply. In combination, these man-made structures are likely to reduce gravel supply significantly and can thus increase armoring and intensify flushing out heterogeneous sorted sediments. As a consequence of artificially determined, supply-limited conditions, the resultant deficits in bed-load transport may lead to continuous riverbed incision with the risk of channel avulsion and riverbed breakthrough during single flood events (Habersack and Klösch 2012). Continuous riverbed incision is the main driver of decoupling floodplains from the required water stage-dependent dynamics of the main river (see Chap.  3).
Fig. 8.1

Conceptual schema of mid- and long-term development of spawning gravel in terms of significant (solid line to dashed line) (a) lack of sediment supply from upstream reaches in rivers with low concentration of fines and (b) lack of sediment supply from upstream with high accumulation of fine sediments in the immobile coarse bed surface (clogging)

Beside problems related to riverbed incision and the coarsening of bed surface, increases in fine sediments are known to change grain size distribution and consequently cause degradation of spawning grounds (Sear and DeVries 2008; Pulg et al. 2013), especially in “supply-limited” rivers (Fig. 8.1b). On the one hand, the armoring of the bed surface reduces or prevents cleaning effects of sediment relocations, which naturally generate suitable spawning habitats in the riverbed.

On the other hand, the increase of fines clogs the pore space and can lead to “sustained clogging” (Fig. 8.1b), since the turnover rate is markedly reduced or prevented even in the case of exceptional high flows. In such situations, washed out soil (e.g., from agricultural land use) or fines (e.g., of a glacier environment) may lead to sedimentation of fines on coarse bed material and/or artificially placed gravel with consequent, negative impacts on embryo survival of gravel-spawning fish through suffocation (Reiser 1998; Greig et al. 2005; Pulg et al. 2013).

Too Much: Consequence of an Increased Fine Sediment Yield

Under natural situations, only extraordinary events (e.g., flooding, torrents) produce “too much” sediment. The “excess” sediments generated in extreme events often raise the issue of fine sediments for analysis and/or management of river ecology. In general, in river morphology (Evans and Wilcox 2014) and fish habitat studies (e.g., Pulg et al. 2013), fine sediments are classified as particles <1 mm. Clogging of interstitial space due to clay intrusion called siltation degrades macroinvertebrate habitats (e.g., Buddensiek 1995). However, also coarse sand (>1 mm) may impact habitats of macroinvertebrates (Leitner et al. 2015).

Fine sediment intrusion (FSI) is part of the natural sediment and morphological dynamics in most river systems (Smith and Smith 1980). Land-use properties (e.g., Allan 2004) and geological (e.g., Walling 2005) and hydrological catchment-scale characteristics (flood disturbances, frequency, and magnitude of daily glacier melt-off) (e.g., Smith and Smith 1980; Milner and Petts 1994) have often been identified as drivers for natural FSI or clogging of surface and subsurface layers. Aside from glacial rivers, human (anthropogenic) disturbances have greater impacts on the fine sediment dynamics than natural processes. Man-made changes, however, might increase as well as decrease the amount of (fine) sediment load with mostly negative impacts on aquatic ecology in case of increases. For example, hydropower may cause significant alterations of the (fine) sediment regime based on the storage of water and the capture of sediment by dams which cause profound downstream changes in the natural patterns of the hydrologic variation and sediment transport (Poff and Hart 2002). In particular, fine sediment may be trapped in reservoirs and artificially released during controlled events, which may lead to variable meso-unit scale deposition patterns and significant alterations of bed-load transport rates downstream (Wohl et al. 2010). Ecological consequences of reservoir flushing are long-term depletions downstream fish stocks (Espa et al. 2015; Buermann et al. 1995) and short-term impacts on macroinvertebrate communities (Rabení et al. 2005; Crosa et al. 2010).

8.3.1 Ecological Adaptations of Macroinvertebrates to Sediment Dynamics

The faunal structure of benthic macroinvertebrates depends on substrate type, diversity, and spatial patch configuration (Beisel et al. 2000). Habitat conditions of macroinvertebrates are to a large extent determined by flow parameters affecting the macroinvertebrates through hydraulic stress near the bottom (Statzner 1981) which is linked to substrate composition (Percival and Whitehead 1929; Beisel et al. 2000). Accordingly, some species prefer the surface of larger substrates where they feed on biofilms in high current, resulting in a flattened body form (Minshall 1967); others that hide in sand and mud are adapted to temporarily low-oxygen concentrations; those who feed on leaves or wood are restricted to organic matter (Schröder et al. 2013). As a consequence, many species are associated to a certain extent to specific habitats, which are composed of either mineral substrate (e.g., sand, gravel stones) or organic matter (e.g., living plants, dead leaves, deadwood) (see examples in Fig. 8.2a). However, habitat preferences frequently change within the life cycle of invertebrate taxa, indicating the importance of mosaic habitat patterns on a microscale (Fig. 8.2b).
Fig. 8.2

(a) Examples of habitat-specific benthic organisms: Perla sp. (macrolithal), Ametropus fragilis (psammal), Nemurella pictetii (fallen leaves), and Lepidostoma basale (deadwood); clockwise from top left; (b) habitat suitability regarding flow velocity of the mayfly Potamanthus luteus in summer (red line, nymphs) and winter (blue line, early instars) at the March River (adapted from Büsch 2014)

In general, benthic invertebrates are adapted to sediment dynamics and natural disturbances (erosion). Animals can usually compensate for infrequent extreme events as floods or ice jams that result in destructive sediment transport. Depending on their autecological adaptions (anatomy, strategy) and stage of development (egg, different larval stages, and pupal stage), animals hide in the interstice or go into drift in case of disturbances. Drift is a means of recolonizing denuded downstream habitats and structuring benthic invertebrate communities (Tonkin and Death 2013). However, to preserve stable self-sustaining populations in cases of extreme events, successive downstream drifting has to be compensated by upstream migration by larval stages or by compensation flights by adult insects (Williams and Hynes 1977).

However, anthropogenically induced, long-term alteration of the streambed can result in dramatic shifts of the benthic faunal composition. A coarsening of the bed surface in “supply-limited” rivers can lead to a decrease of macroinvertebrate diversity and/or density for those taxa with habitat preferences for fine sediments comprising certain Oligochaeta, Bivalvia, Diptera, or burrowing Ephemeroptera species. Nevertheless, as many studies show that only a low number of taxa indicate a clear preference for fine substrates (e.g., Minshall 1984; Jowett et al. 1991; Leitner et al. 2015; Graf et al. 2016), the more serious effect in supply-limited river stretches is the clogging of the interstices and embedding of coarse substrate by fines. This phenomenon results in a decline in diversity and abundance of interstices inhabiting sprawlers, such as many Plecoptera and Ephemeroptera species (e.g., Weigelhofer and Waringer 2003).

In particular, anthropogenically induced, fine sediment deposition and siltation in streambeds seriously alters benthic fauna composition and, thus, is becoming a considerable stress for rivers throughout the world. Following Wood and Armitage (1997, Fig. 8.3), increased fine sediment yield affects macroinvertebrates (1) in changing substrate suitability for some taxa (Erman and Ligon 1988; Richards and Bacon 1994), (2) in increasing drift due to sedimentation or substrate instability (Culp and Davies 1985; Rosenberg and Wiens 1978), (3) in limiting respiration by deposition of fine sediments on respiration organs (Lemly 1982) or low-oxygen concentrations in the interstices (Eriksen 1966), and (4) in deteriorating feeding conditions due to effects of increased suspended solids on filter feeders (Aldridge et al. 1987) and in the reduction of the food value of the periphyton (Cline et al. 1982; Graham 1990) as well as prey organisms (Broekhuizen et al. 2001; Yamada and Nakamura 2002; Jones et al. 2012).
Fig. 8.3

A holistic overview of fine sediment in the lotic ecosystem, after Wood and Armitage (1997) (© Environmental management, Biological effects of fine sediment in the lotic environment, 21(2), 1997, 203–217, Wood, P. J., Armitage, P. D. With permission of Springer)

Consequently, increased input of fine sediments leads to a decrease in diversity, abundance, and biomass of macroinvertebrates as well as to a shift in community structure (Berkman and Rabeni 1987; Wood and Armitage 1997; Angradi 1999; Leitner et al. 2015). For example, Graf et al. (2016) demonstrated that only Chironomidae and Oligochaeta show a habitat preference for sand or are at least more tolerant to this type of substrate, while other taxa belonging to the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) show preferences for coarser substrate types and are highly sensitive to siltation.

Briefly, increased fine sediment yield has serious effects on benthic macroinvertebrates in lotic systems, emerging as a steady, often unnoticed, process with a high-risk potential for affecting biodiversity leading to critical ecological degradation.

8.3.2 Ecological Adaptations of Lithophilic Fishes

Sediments play a crucial role in the life cycles of many riverine fish species. This is not surprising since fish fauna had to evolve within the frame of habitat conditions governed by sediment dynamics. Fishes developed strategies or adaptions to cope with dynamic and often stochastically changing sediment conditions. Extensive sediment transport and related relocation are generally destructive events decreasing the survival of incubated egg and juvenile stages of salmonids (e.g., Cattanéo et al. 2002; Lobón-Cerviá and Rincón 2004; Unfer et al. 2011). While the older life stages can actively search for cover, early juvenile stages are exposed to erosive forces that result in high mortality rates. On the other hand, flood events and related sediment relocation reshape the riverbed and refine potential spawning ground for the upcoming spawning period (Poff et al. 1997; Unfer et al. 2011).

For gravel-spawning fish species (lithophilic, most rheophilic species in Europe, such as salmonids and many cyprinids, Fig. 8.4), suitable spawning sediment (bed material composition) and further abiotic components such as water temperature, oxygen concentration, or flow velocity are essential for successful recruitment. Lack of suitable spawning substrate can create bottlenecks for population size and production rates (Pulg et al. 2013). Excessively large grains (large cobble) or armor layers prevent salmonids from redd building (Kondolf 2000), while, on the other hand, high percentages of small grains (fine gravel, sand, silt, clay) do not allow successful reproduction due to reduced permeability and, consequently, insufficient supply of water and oxygen (Sear and DeVries 2008). Besides fines, washout of spawning gravel as well as reduced gravel supply from upstream sources can limit spawning habitats (Barlaup et al. 2008).
Fig. 8.4

Egg deposition of on-substrate spawners (left, e.g., many cyprinids) and interstitial spawners (e.g., many salmonids)

Riverine fish depend on substrate also at older life stages (Fig. 8.5). Juveniles of many salmonids spend long periods of their life in the shelter of the sediment, and adults seek shelter on the porous river bottom or behind boulders (Jonsson and Jonsson 2011). Other species (predominately cyprinids) are drifting downstream as larvae and depend on a variable river morphology providing coves, side channels, and oxbows, which are likewise structured by riverbed sediments (Jungwirth et al. 2003).
Fig. 8.5

(a) Habitat use of Atlantic Salmon and brown trout juveniles in relation to grain size distribution in Norwegian salmonid rivers (figure adapted from Pulg et al. 2017). (b) Adult Atlantic salmon of approx. 100 cm in length seeking shelter in the river bottom of the boulder-dominated cascade river Nordøla in Western Norway (Photo: Ulrich Pulg).

8.4 Sediment Management Options

Options for sediment management in river catchments are manifold. Basically, they can be divided into (1) structural and (2) nonstructural measures, which can be established on various river scales, including potential consequences (improvements) for downstream river reaches. As an important nonstructural measure, land-use change has to be mentioned. Due to the fact that increased erosion of fines is frequently associated with agricultural land use and intensive forestry (Walling 1990), a reduction of input of erodible soil surfaces provides a management option, especially to prevent clogging of bed sediments (Bakker et al. 2008).

Structural measures on a patch scale (e.g., installation of boulders or deadwood) are useful to create patches of habitats providing the required substratum quality (Hauer 2015). Structural features, such as boulders, have the advantage in that specifically during high (scouring) flows, they provide sheltering habitats in the wake zone accompanied by reduced flow velocities and/or bottom shear stress. Boulder placement or instream use of deadwood can also have effects on the hydraulic conditions and river morphology and, hence, indirectly affect the biota. For example, lateral scour pools with coarse substrate are formed if the flow is vertically or laterally constricted by boulders (Wood-Smith and Buffington 1996).

Examples of structural measures on a larger/local scale are the implementation of river widenings or changes in energy slope (e.g., ramps). Both exhibit local-scale impacts on the sediment transport capacity of rivers. River widenings, in particular, resemble an opportunity to stop riverbed incision, which is often the consequence of a disturbed sediment continuum and channel rectification, specifically in alpine environments. Compared to regulated river sections, local channel widenings increase the hydraulic radius, leading to a decrease in velocity and bottom shear stress (Hauer et al. 2015). In widened river sections, the sediment transport capacity is reduced, which can stop riverbed incision by increasing the aggradation of transported sediments.

Changing the bed (energy) slope is a hydraulic engineering opportunity to influence sediment transport and sediment dynamics when sediment management is required. A large number of artificial transversal obstructions (mainly ramps) are installed to stop ongoing riverbed incision in rectified stretches of alpine gravel bed rivers (DeBene et al. 2016). For this purpose, the bed gradient is reduced between the ramps and the differences in height, and consequently high erosional potential of the flow is controlled by the ramp and the downstream scouring pool (Pagliara 2007). In addition to these technical concepts, by reducing energy slope for channel stability, changes in the bed slope can be explicitly targeted in river restoration (e.g., Habersack et al. 2010) as well as spawning habitat restoration projects (Pulg et al. 2013; Hauer et al. 2015).

Artificial gravel dumping, as an example of structural improvements, is a restoration measure frequently applied below dams (Brown and Pasternack 2008). It affects geomorphic units at meso-scales and thus hydraulic patterns on the microscale (Pasternack 2008). Wheaton et al. (2004) highlight the use of artificial gravel placement as one possible measure to restore or enhance hydro-morphologically suitable spawning habitat conditions for salmonids. For example, in Western Norway, the restoration of anthropogenically impacted (partially destroyed) spawning habitats of Atlantic salmon (Salmo salar) was mainly achieved by artificial gravel dumping (e.g., Barlaup et al. 2008) and the restoration of fluvial processes (Fjeldstad et al. 2012). Other restoration techniques include hydraulic structure placement (e.g., single boulders or groins), mainly to create suitable water depths and flow velocities combined with specific sediment sorting, or an “artificial enhancement” of existing spawning gravels by periodic turnovers of spawning substrate to reduce the amounts of aggregated fine sediments at spawning grounds. The problem inherent with all the above mentioned spawning habitat improvement methods (gravel cleaning, gravel dumping, hydraulic adjustments) is that they were designed to increase the habitat suitability for target species during median or low flow conditions (spawning/incubation period, Wheaton et al. 2004) or to reduce the deposition of fine sediments (Pulg et al. 2013). However, the stability and/or scouring depth of spawning substrate during high flow conditions is typically not assessed in spawning habitat restoration design (short- to mid-term time scale) (e.g., DeVries 2008; Lisle 1989; Buffington et al. 2004).

Concerning sediment management actions in relation to hydropower production, many recent studies focus on sediment management techniques in the reservoir (Schleiss et al. 2010). In this context, very often measures removing sediments from the reservoir, such as mechanical and hydraulic dredging (reservoir flushing), are used (Gaisbauer and Knoblauch 2001). Moreover, sediment bypass systems are frequently investigated and described mitigation measures for sediment management in reservoirs. The diversion of sediments through a tunnel (bypassing) can be seen as a preventive and catchment-scale measure against reservoir sedimentation (Boillat and Pougatsch 2000), as it inhibits the input of bed load and part of the suspended load into the reservoir, ensures sediment continuity during floods (Vischer and Chervet 1996), and thus can improve river ecology and sustainability by preventing riverbed erosion downstream the dam (Schleiss and Boes 2011). Turbidity currents are gravity currents driven by the density contrast between sediment-laden fluid and ambient fluid and are an additional sediment management option (Baas et al. 2005). Moreover, dredging of (fine) sediment material is not only important in alpine hydropower reservoirs but also in run-of-river plants in particular. The dredged material needs to be considered in the morpho-dynamic evolution and sediment balance of the reservoir, while the material dumped downstream of the dam yields an important sediment input on the downstream river reach.

8.5 Conclusions and Outlook

Depending on the morphological river type, sediments can be hydraulically habitat forming or just components of a morphological feature that determines the hydraulic patterns of a river. Aquatic biota (e.g., macroinvertebrates, fish) contain different sediment requirements (e.g., morphological adaption) concerning the sediment quantity and distribution in relation to different life stages. Moreover, different reactions in terms of an increased sediment surplus or sediment deficits by a disturbed sediment regime are given. Thus, among the most important issues for sustainable river management in the future are studies on processes and consequently an improved process understanding of sediment dynamics on all river scales. Based on this improved process, understanding restoration measures has to be adjusted to cope with, e.g., increased fine sediments, which are now often trapped in reservoirs. Hence, a holistic view of the river systems and driving abiotic processes has to be targeted for future management—including responsible actors in the present sediment management like water management authorities as well as hydropower companies.

Notes

Acknowledgement

The financial support by the Austrian Federal Ministry of Science, Research and Economy and the National Foundation of Research, Technology and Development is gratefully acknowledged.

References

  1. Aldridge DW, Payne BS, Miller AC (1987) The effects of intermittent exposure to suspended solids and turbulence on three species of freshwater mussels. Environ Pollut 45:17–28PubMedCrossRefGoogle Scholar
  2. Allan JD (2004) Landscapes and riverscapes: the influence of land use on stream ecosystems. Annu Rev Ecol Evol Syst 35:257–284CrossRefGoogle Scholar
  3. Andrews ED (1984) Bed-material entrainment and hydraulic geometry of gravel-bed rivers in Colorado. Bull Geol Sot Am 95:371–378CrossRefGoogle Scholar
  4. Angradi TR (1999) Fine sediment and macroinvertebrate assemblages in Appalachian streams: a field experiment with biomonitoring applications. J N Am Benthol Soc 18:49–66CrossRefGoogle Scholar
  5. Baas JH, Mccaffrey WD, Haughton PD, Choux C (2005) Coupling between suspended sediment distribution and turbulence structure in a laboratory turbidity current. J Geophys Res Oceans 110(C11):1978–2012CrossRefGoogle Scholar
  6. Bakker MM, Govers G, van Doorn A, Quetier F, Chouvardas D, Rounsevell M (2008) The response of soil erosion and sediment export to land-use change in four areas of Europe: the importance of landscape pattern. Geomorphology 98:213–226CrossRefGoogle Scholar
  7. Barlaup BT, Gabrielsen SE, Skoglund H, Wiers T (2008) Addition of spawning gravel – a means to restore spawning habitat of Atlantic Salmon (Salmo salar L.), and anadromous and resident brown trout (Salmo trutta L.) in regulated rivers. River Res Appl 24:543–550CrossRefGoogle Scholar
  8. Beisel JN, Usseglio-Polatera P, Moreteau JC (2000) The spatial heterogeneity of a river bottom: a key factor determining macroinvertebrate communities. In: Assessing the ecological integrity of running waters. Springer Netherlands, Cham, pp 163–171CrossRefGoogle Scholar
  9. Berkman HE, Rabeni CF (1987) Effect of siltation on stream fish communities. Environ Biol Fish 18:285–294CrossRefGoogle Scholar
  10. Boillat JL, Pougatsch H (2000) State of the art of sediment management in Switzerland. Proceedings of the international workshop and symposium on reservoir sedimentation management, pp 35–45Google Scholar
  11. Brizga SO, Finlayson BL (1990) Channel avulsion and river metamorphosis: the case of the Thomson River, Victoria, Australia. Earth Surf Process Landf 15(5):391–404CrossRefGoogle Scholar
  12. Broekhuizen N, Parkyn S, Miller D (2001) Fine sediment effects on feeding and growth in the invertebrate grazers Potamopyrgus antipodarum (Gastropoda, Hydrobiidae) and Deleatidium sp (Ephemeroptera, Leptophlebiidae). Hydrobiologia 457:125–132CrossRefGoogle Scholar
  13. Brooks AP, Brierley GJ (1997) Geomorphic responses of lower Bega River to catchment disturbance, 1851–1926. Geomorphology 18:291–304CrossRefGoogle Scholar
  14. Brown RA, Pasternack GB (2008) Engineering channel controls limiting spawning habitat rehabilitation success on regulated gravel bed rivers. Geomorphology 97:631–654CrossRefGoogle Scholar
  15. Buddensiek V (1995) The culture of juvenile freshwater pearl mussels Margaritifera margaritifera L in cages: a contribution to conservation programmes and the knowledge of habitat requirements. Biol Conserv 74:33–40CrossRefGoogle Scholar
  16. Buermann Y, Du Preez HH, Steyn GJ, Harmse JT, Deacon A (1995) Suspended silt concentrations in the lower Olifants River (Mpumalanga) and the impact of silt releases from the Phalaborwa Barrage on water quality and fish survival. Koedoe 38(2):11–34CrossRefGoogle Scholar
  17. Buffington JM, Montgomery DR, Greenberg HM (2004) Basin-scale availability of salmonid spawning grave as influenced by channel type and hydraulic roughness in mountain catchments. Can J Fish Aquat Sci 61:2085–2096CrossRefGoogle Scholar
  18. Bunte K, Abt SR (2001) Sampling surface and subsurface particle-size distributions in wadable gravel- and cobble-bed streams for analysis of sediment transport, hydraulics, and stream bed monitoring. Gen. Techn. Rep. RMRS-GTR-74. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountains Research Station. 428 pGoogle Scholar
  19. Büsch M (2014) Hydraulische Habitatpräferenzen ausgewählter Makrozoobenthos-Taxa an der March und der Thaya in Niederösterreich und ihre Bedeutung für Restaurierungsmaßnahmen. In: Masterarbeit. Universität für Bodenkultur, WienGoogle Scholar
  20. Cattanéo F, Lamouroux N, Breil P, Capra H (2002) The influence of hydrological and biotic processes on brown trout (Salmo trutta) population dynamics. Can J Fish Aquat Sci 59(1):12–22CrossRefGoogle Scholar
  21. Chartrand SM, Whiting PJ (2000) Alluvial architecture in headwater streams with special emphasis on step–pool topography. Earth Surf Process Landf 25(6):583–600CrossRefGoogle Scholar
  22. Chin A (1999) The morphologic structure of step–pools in mountain streams. Geomorphology 27(3–4):191–204CrossRefGoogle Scholar
  23. Cline LD, Short RA, Ward JV (1982) The influence of highway construction on the macroinvertebrates and epilithic algae of a high mountain stream. Hydrobiologia 96(2):149–159CrossRefGoogle Scholar
  24. Crosa G, Castelli E, Gentili G, Espa P (2010) Effects of suspended sediments from reservoir flushing on fish and macroinvertebrates in an alpine stream. Aquat Sci 72:85–95CrossRefGoogle Scholar
  25. Culp JM, Davies RW (1985) Responses of benthic macroinvertebrate species to manipulation of interstitial detritus in Carnation Creek, British Columbia. Can J Fish Aquat Sci 42(1):139–146CrossRefGoogle Scholar
  26. DeBene A, Diermayr M, Hauer C (2016) Erfahrungen aus dem naturnahen Rampenbau mit Berücksichtigung der WRRL am Beispiel des Ischlflusses. Österreichische Wasser- und Abfallwirtschaft 11:534–544CrossRefGoogle Scholar
  27. DeVries P (2008) Bed disturbance processes and the physical mechanisms of scour in salmonid spawning habitat. In: American Fisheries Society Symposium, vol 65. American Fisheries Society, Bethesda, pp 121–147Google Scholar
  28. Directive 2000/60/EC (2000) The EU water framework directive – integrated river basin management for Europe. European CommissionGoogle Scholar
  29. Dudgeon D, Arthington AH, Gessner MO et al (2006) Freshwater biodiversity: importance, threats, status and conservation challenges. Biol Rev 81:163–182PubMedCrossRefGoogle Scholar
  30. Eriksen CH (1966) Diurnal limnology of two highly turbid puddles. Verhandlungen des Vereins für Limnologie 16:507–514Google Scholar
  31. Erman DC, Ligon FK (1988) Effects of discharge fluctuation and the addition of fine sediment on stream fish and macroinvertebrates below a water-filtration facility. Environ Manag 12(1):85–97CrossRefGoogle Scholar
  32. Espa P, Crosa G, Gentili G, Quadroni S, Petts G (2015) Downstream ecological impacts of controlled sediment flushing in an Alpine valley river: a case study. River Res Appl 31(8):931–942CrossRefGoogle Scholar
  33. Evans E, Wilcox AC (2014) Fine sediment infiltration dynamics in a gravel-bed river following a sediment pulse. River Res Appl 30(3):372–384CrossRefGoogle Scholar
  34. Fjeldstad HP, Barlaup BT, Stickler M, Gabrielsen SE, Alfredsen K (2012) Removal of weirs and the influence on physical habitat for salmonids in a Norwegian river. River Res Appl 28(6):753–763CrossRefGoogle Scholar
  35. Frisell CA, Liss WJ, Warren CE, Hurley MD (1996) A hierachical framework for stream habitat classification: viewing streams in a watershed context. Environ Manag 10:199–214CrossRefGoogle Scholar
  36. Gaisbauer H, Knoblauch H (2001) Feststoffmanagement bei Stauanlagen. Österreichische Wasser- und Abfallwirtschaft 53(11–12):265–268Google Scholar
  37. Geist J, Auerswald K (2007) Physicochemical stream bed characteristics and recruitment of the freshwater pearl mussel (Margaritifera margaritifera). Freshw Biol 52:2299–2316CrossRefGoogle Scholar
  38. Graf W, Leitner P, Hanetseder I, Ittner LD, Dossi F, Hauer C (2016) Ecological degradation of a meandering river by local channelization effects: a case study in an Austrian lowland river. Hydrobiologia 772(1):145–160CrossRefGoogle Scholar
  39. Graham AA (1990) Siltation of stone-surface periphyton in rivers by clay-sized particles from low concentrations in suspention. Hydrobiologia 199:107–115CrossRefGoogle Scholar
  40. Grant GE, Swanson FJ, Wolman MG (1990) Pattern and origin of stepped-bed morphology in high-gradient streams, Western Cascades, Oregon. Geol Soc Am Bull 102:340–352CrossRefGoogle Scholar
  41. Greig SM, Sear DA, Carling PA (2005) The impact of fine sediment accumulation on the survival of incubating salmon progeny: implications for sediment management. Sci Total Environ 344(1):241–258PubMedCrossRefGoogle Scholar
  42. Habersack H (2000) The river scaling concept (RSC): a basis for ecological assessments. Hydrobiologia 422/423:49–60CrossRefGoogle Scholar
  43. Habersack H, Klösch M (2012) Monitoring und Modellierung von eigendynamischen Aufweitungen an Drau, Mur und Donau. Österreichische Wasser- und Abfallwirtschaft 64:411–422CrossRefGoogle Scholar
  44. Habersack H, Piégay H (2008) River restoration in the Alps and their surroundings: past experience and future challenges. In: Habersack H, Piegay H, Rinaldi M (eds) Gravel-bed rivers VI: from process understanding to river restoration. Elsevier, AmestrdamGoogle Scholar
  45. Habersack H, Liedermann M, Tritthart M, Hauer C, Klösch M, Klasz G, Hengl M (2010) Maßnahmen für einen modernen Flussbau betreffend Sohlstabilisierung und Flussrückbau–Granulometrische Sohlverbesserung, Buhnenoptimierung, Uferrückbau und Gewässervernetzung. Österreichische Wasser und Abfallwirtschaft 11–12:571–581Google Scholar
  46. Harvey AM (2001) Coupling between hillslopes and channels in upland fluvial systems: implications for landscape sensitivity, illustrated from the Howgill Fells, northwest England. Catena 42:225–250CrossRefGoogle Scholar
  47. Hauer C (2015) Review of hydro-morphological management criteria on a river basin scale for preservation and restoration of freshwater pearl mussel habitats. Limnologica 50:40–53CrossRefGoogle Scholar
  48. Hauer C, Unfer G, Habersack H, Pulg U, Schnell J (2013) Bedeutung von Flussmorphologie und Sedimenttransport in Bezug auf die Qualität und Nachhaltigkeit von Kieslaichplätzen. KW–Korrespondenz Wasserwirtschaft 4/13:189–197Google Scholar
  49. Hauer C, Blamauer B, Mühlmann H, Habersack H (2014) Morphodynamische Aspekte der Ökohydraulik und Habitatmodellierung im Kontext der rechtlichen Rahmenbedingungen. Österr. Wasser- und Abfallwirtschaft, 56.JG, 66:169–178CrossRefGoogle Scholar
  50. Hauer C, Pulg U, Gabrielsen SE, Barlaup BT (2015) Application of step-backwater modelling for salmonid spawning habitat restoration in Western Norway. Ecohydrology 8(7):1239–1261CrossRefGoogle Scholar
  51. Henderson FM (1963) Stability of alluvial channels. Trans Am Soc Civ Eng l28:657–686Google Scholar
  52. Hjülström F (1935) The morphological activity of rivers as illustrated by river Fyris. Bulletin of Geological Institute, 25Google Scholar
  53. Höfler S, Hauer C, Gumpinger C (2016) Ökologische Maßnahmen an kleinen und mittelgroßen Fließgewässern -Auswirkungen auf die Qualitätselemente der Europäischen Wasserrahmenrichtlinie und Grenzen der Wirksamkeit – unter besonderer Berücksichtigung der Feinsedimentproblematik. Österreichische Wasser- und Abfallwirtschaft 11:519–533CrossRefGoogle Scholar
  54. Hopf G (2006) Die Sanierung der unteren Salzach. – LWF Wissen, 55, 62–66, 8 Abb., Freising (Bayerische Landesanstalt für Wald und Forstwirtschaft)Google Scholar
  55. Jäger E, Hauer C, Habersack H (2018) A novel tool in integrated flood risk management: river-adapted vegetation management VEMAFLOODGoogle Scholar
  56. Jones JI, Murphy JF, Collins AL, Sear DA, Naden PS, Armitage PD (2012) The impact of fine sediment on macro-invertebrates. River Res Appl 28(8):1055–1071CrossRefGoogle Scholar
  57. Jungwirth M, Haidvogel G, Muhar S, Schmutz S (2003) Angewandte Fischökologie an Fließgewässern. UTB Facultas. 547 ppGoogle Scholar
  58. Jonsson B, Jonsson N (2011) Migrations. In: Ecology of Atlantic Salmon and Brown Trout. Springer, Dordrecht, pp 247–325CrossRefGoogle Scholar
  59. Jowett IG, Richardson J, Biggs BJ, Hickey CW, Quinn JM (1991) Microhabitat preferences of benthic invertebrates and the development of generalised Deleatidium spp. habitat suitability curves, applied to four New Zealand rivers. N Z J Mar Freshw Res 25(2):187–199CrossRefGoogle Scholar
  60. Keller EA, Melhorn WN (1978) Rhythmic spacing and origin of pools and riffles. Geol Soc Am Bull 89(5):723–730CrossRefGoogle Scholar
  61. Kondolf GM (1997) PROFILE: hungry water: effects of dams and gravel mining on river channels. Environ Manag 21(4):533–551CrossRefGoogle Scholar
  62. Kondolf GM (2000) Assessing salmonid spawning gravel quality. Trans Am Fish Soc 129(1):262–281CrossRefGoogle Scholar
  63. Leitner P, Hauer C, Ofenbock T, Pletterbauer F, Schmidt-Kloiber A, Graf W (2015) Fine sediment deposition affects biodiversity and density of benthic macroinvertebrates: a case study in the freshwater pearl mussel river Waldaist (Upper Austria). Limnologica 50:54–57CrossRefGoogle Scholar
  64. Lemly AD (1982) Modification of benthic insect communities in polluted streams: combined effects of sedimentation and nutrient enrichment. Hydrobiotogia 87:222–245Google Scholar
  65. Leopold LB, Wolman MG, Miller JP (1964) Fluvial processes in geomorphology. Freeman, San Francisco, CA, 522 ppGoogle Scholar
  66. Lisle TE (1986) Stabilization of gravel channel by a large streamside obstruction and bedrock bends, Jacoby Creek, northwestern California. Geol Soc Am Bull 97:999–1011CrossRefGoogle Scholar
  67. Lisle TE (1989) Sediment transport and resulting deposition in spawning gravels, north coastal California. Water Resour Res 25:1303–1319CrossRefGoogle Scholar
  68. Lobón-Cerviá J, Rincón PA (2004) Environmental determinants of recruitment and their influence on the population dynamics of stream-living brown trout Salmo trutta. Oikos 105:641–646CrossRefGoogle Scholar
  69. Maddock I (1999) The importance of physical habitat assessment for evaluating river health. Freshw Biol 41(2):373–391CrossRefGoogle Scholar
  70. Maritan A, Rinaldo A, Rigon R, Giacometti A, Rodríguez-Iturbe I (1996) Scaling laws for river networks. Phys Rev E53:1510CrossRefGoogle Scholar
  71. Maxwell AR, Papanicolaou AN (2001) Step-pool morphology in high-gradient streams. Int J Sediment Res 16(3):380–390Google Scholar
  72. Milner AM, Petts GE (1994) Glacial rivers: physical habitat and ecology. Freshw Biol 32(2):295–307CrossRefGoogle Scholar
  73. Minshall GW (1967) Role of allochthonous detritus in the trophic structure of a woodland springbrook community. Ecology 48:139–149CrossRefGoogle Scholar
  74. Minshall GW (1984) Aquatic insect-substratum relationships. In: Resh VH, Rosenberg DM (eds) The ecology of aquatic insects. Praeger Publishers, New York, pp 358–400Google Scholar
  75. Montgomery DR, Buffington JM (1997) Channel reach morphology in mountain drainage basins. Geol Soc Am Bull 109:596–611CrossRefGoogle Scholar
  76. Newson MD, Newson CL (2000) Geomorphology, ecology and river channel habitat: mesoscale approaches to basin-scale challenges. Prog Phys Geogr 24:195–217CrossRefGoogle Scholar
  77. Pagliara S (2007) Influence of sediment gradation on scour downstream of block ramps. J Hydraul Eng 133(11):1241–1248CrossRefGoogle Scholar
  78. Pasternack GB (2008) Spawning habitat rehabilitation: advances in analysis tools. In: Sear DA, DeVries P (eds) Salmon spawning habitat in rivers, vol 65. American Fisheries Symposium, Bethesda, pp 321–349Google Scholar
  79. Percival E, Whitehead H (1929) A quantitative study of some types of stream bed. J Ecol 17:282–314CrossRefGoogle Scholar
  80. Peterson DF, Mohanty PK (1960) Flume studies of flow in steep, rough channels. J Hydraul Div/Am Soc Civil Eng 86:55–76Google Scholar
  81. Phillips JD (2002) Geomorphic impacts of flash flooding in a forested headwater basin. J Hydrol 269:236–250CrossRefGoogle Scholar
  82. Poff NL, Hart DD (2002) How dams vary and why it matters for the emerging science of dam removal an ecological classification of dams is needed to characterize how the tremendous variation in the size, operational mode, age, and number of dams in a river basin influences the potential for restoring regulated rivers via dam removal. Bioscience 52(8):659–668CrossRefGoogle Scholar
  83. Poff NL, Allan JD, Bain MB, Karr JR, Prestergaard KL, Richter BD, Sparks RE, Stromberg JC (1997) The natural flow regime. Bioscience 47:769–784CrossRefGoogle Scholar
  84. Pulg U, Barlaup BT, Sternecker K, Trepl L, Unfer G (2013) Restoration of spawning habitats of brown trout (Salmo trutta) in a regulated chalk stream. River Res Appl 29:172–182CrossRefGoogle Scholar
  85. Pulg U, Barlaup BT, Skoglund H, Velle G, Gabrielsen SE, Stranzl SF, Espedal EO, Lehmann GB, Wiers T, Skår B, Normann E, Fjeldstad HP (2017) Tiltakshåndbok for bedre fysisk vannmiljø: God praksis ved miljøforbedrende tiltak i elver og bekker. Uni Research AS. 180 pages LFI Uni Miljø (296)Google Scholar
  86. Rabení CF, Doisy KE, Zweig LD (2005) Stream invertebrate community functional responses to deposited sediment. Aquat Sci 67(4):395–402CrossRefGoogle Scholar
  87. Reiser DW (1998) Sediment gravel bed rivers: ecological and biological considerations. In: Gravel-bed rivers in the environment. Water Research Centre, Colorado, pp 199–228Google Scholar
  88. Rice S (1998) Which tributary disrupt downstream fining along gravel-bed rivers? Geomorphology 22:39–56CrossRefGoogle Scholar
  89. Rice S, Church M (1998) Grain size along two gravel-bed rivers: statistical variation, spatial patterns and sedimentary links. Earth Surf Process Landf 23:345–363CrossRefGoogle Scholar
  90. Richards C, Bacon KL (1994) Influence of fine sediment on macroinvertebrate colonisation of surface and hyporheic stream sediments. Great Basin Naturalist 54:106–113Google Scholar
  91. Rinaldi M, Casagli N (1999) Stability of streambanks formed in partially saturated soils and effects of negative pore water pressures: the Sieve River (Italy). Geomorphology 26(4):253–277CrossRefGoogle Scholar
  92. Rosenberg DM, Wiens AP (1978) Effects of sediment addition on macrobenthic invertebrates in a northern Canadian river. Water Res 12(10):753–763CrossRefGoogle Scholar
  93. Schleiss A, Boes R (2011) Dams and reservoirs under changing challenges. Proceedings of the international symposium on dams and reservoirs under changing challenges, 79 Annual Meeting of ICOLD, June 2011, Swiss Committee on Dams, LucerneGoogle Scholar
  94. Schleiss A, De Cesare G, Jenzer Althaus J (2010) Verlandung der Stauseen gefährdet die nachhaltige Nutzung der Wasserkraft. Wasser Energie Luft 102(1):31–40Google Scholar
  95. Schröder M, Kiesel J, Schattmann A, Jähnig SC, Lorenz AW, Kramm S, Hering D (2013) Substratum associations of benthic invertebrates in lowland and mountain streams. Ecol Indic 30:178–189CrossRefGoogle Scholar
  96. Schumm SA (1977) The fluvial system. Wiley, New York. 338 ppGoogle Scholar
  97. Sear DA, DeVries P (2008) Salmonid spawning habitat in rivers: physical controls, biological responses, and approaches to remediation, vol 65. American Fisheries Society, BethesdaGoogle Scholar
  98. Sidle RC (1988) Bed load transport regime of a small forest stream. Water Resour Res 24:201–218CrossRefGoogle Scholar
  99. Smith DG, Smith ND (1980) Sedimentation in anastomosed river systems: examples from alluvial valley near Bannf, Alberta. J Sediment Res 50(1):157–164CrossRefGoogle Scholar
  100. Statzner B (1981) A method to estimate the population size of benthic macroinvertebrates in streams. Oecologia 51(2):157–161PubMedCrossRefGoogle Scholar
  101. Sutherland AJ (1987) Static armour layers by selective erosion. In: Thorne CR, Bathurst JC, Hey RD (eds) Sediment transport in gravel-bed rivers. Wiley, Chichester, pp 243–260Google Scholar
  102. Sutherland AB, Meyer JI, Gardiner EP (2002) Effects of land cover on sediment regime and fish assemblage structure in four southern Appalachian streams. Freshw Biol 47:1791–1805CrossRefGoogle Scholar
  103. Tonkin JD, Death RG (2013) Macroinvertebrate drift-benthos trends in a regulated river. Fundam Appl Limnol/Archiv für Hydrobiologie 182(3):231–245CrossRefGoogle Scholar
  104. Trainor K, Church M (2003) Quantifying variability in stream channel morphology. Water Resour Res 39.  https://doi.org/10.1029/2003WR001971
  105. Unfer G, Hauer C, Lautsch E (2011) The influence of hydrology on the recruitment of brown trout in an Alpine river, the Ybbs River. Austria Ecol Freshw Fish 20:438–448CrossRefGoogle Scholar
  106. Vischer D, Chervet A (1996) Geschiebe-Umleitstollen bei Stauseen; Möglichkeiten und Grenzen. Mitteilungen der Versuchsanstalt fur Wasserbau, Hydrologie und Glaziologie an der Eidgenossischen Technischen Hochschule Zurich 143:26–43Google Scholar
  107. Walling DE (1990) Linking the field to the river: Sediment delivery from agricultural land. In: Boardman J, Foster IDL, Dearing JA (eds) Soil erosion on agricultural land. Wiley, Chichester, pp 129–152Google Scholar
  108. Walling DE (2005) Tracing suspended sediment sources in catchments and river systems. Sci Total Environ 344(1):159–184PubMedCrossRefGoogle Scholar
  109. Ward JV, Stanford JA (1995) Ecological connectivity in alluvial river ecosystems and its disruption by flow regulation. Regul Rivers Res Manag 11:105–119CrossRefGoogle Scholar
  110. Weigelhofer G, Waringer J (2003) Vertical distribution of benthic macroinvertebrates in riffles versus deep runs with differing contents of fine sediments (Weidlingbach, Austria). Int Rev Hydrobiol 88(3–4):304–313CrossRefGoogle Scholar
  111. Wheaton JM, Pasternack GB, Merz JE (2004) Spawning habitat rehabilitation-II. Using hypothesis development and testing in design, Mokelumne river, California, USA. Int J River Basin Manag 2(1):21–37CrossRefGoogle Scholar
  112. Whittaker JG (1987) Sediment transport in step-pool streams. In: Sediment transport in gravel-bed rivers. Wiley, New York, pp 545–579Google Scholar
  113. Williams DD, Hynes HBN (1977) Benthic community development in a new stream. Can J Zool 55(7):1071–1076CrossRefGoogle Scholar
  114. Wohl EE (2013) Mountain rivers revisited, American Geophysical Union. Print, 574 pp. ISBN: 9780875903231, Online ISBN: 9781118665572, doi:  https://doi.org/10.1029/WM019
  115. Wohl EE, Merritt DM (2008) Reach-scale channel geometry of mountain streams. Geomorphology 93:168–185CrossRefGoogle Scholar
  116. Wohl EE, Cenderelli DA, Dwire KA, Ryan-Burkett SE, Young MK, Fausch KD (2010) Large in-stream wood studies: a call for common metrics. Earth Surf Process Landf 35(5):618–625Google Scholar
  117. Wood PJ, Armitage PD (1997) Biological effects of fine sediment in the lotic environment. Environ Manag 21(2):203–217CrossRefGoogle Scholar
  118. Wood-Smith RD, Buffington JM (1996) Multivariate geomorphic analysis of forest streams: implications for assessment in landuse impacts on channel conditions. Earth Surf Process Landf 21:377–393CrossRefGoogle Scholar
  119. Yamada H, Nakamura F (2002) Effect of fine sediment deposition and channel works on periphyton biomass in the Makomanai River, northern Japan. River Res Appl 18(5):481–493CrossRefGoogle Scholar

Copyright information

© The Author(s) 2018

Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. The images or other third party material in this book are included in the book's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the book's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

Authors and Affiliations

  • Christoph Hauer
    • 1
  • Patrick Leitner
    • 2
  • Günther Unfer
    • 2
  • Ulrich Pulg
    • 3
  • Helmut Habersack
    • 1
  • Wolfram Graf
    • 2
  1. 1.Christian Doppler Laboratory for Sediment Research and Management, Institute of Water Management, Hydrology and Hydraulic EngineeringUniversity of Natural Resources and Life SciencesViennaAustria
  2. 2.Institute of Hydrobiology and Aquatic Ecosystem ManagementUniversity of Natural Resources and Life SciencesViennaAustria
  3. 3.Uni Research Environment, Laboratory for Fresh Water Ecology and Inland Fisheries (LFI)BergenNorway

Personalised recommendations