bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface water connection and the macrozoobenthos of two types of floodplains on the upper rhine
Authors: Obrdlik Petr , Fuchs Ulrike 
Published: February 2007

AbstractMacrozoobenthos (especially gastropods) abundance data have been used to ordinate sampling stations on two floodplains of the Upper Rhine with different hydraulic regimes: 30 species of gastropods were recorded in the area actively inundated by the Rhine, while backwaters that have not been flooded for over 50 years housed only 19 species.Potamopyrgus antipodarum is a characteristic species of the permanent aquatic biotopes fed by groundwater and connected with other floodplain waters. Small, isolated, and drying‐up former lateral channels and pools, slowly inundated during a flood, are characterized by Planorbis planorbis with Bathyomphalus contortus. Gyralus albus and Valvata cristata are characteristic of small, partly isolated, and partly drying‐up water bodies of the active floodplain, which are inundated rapidly and very turbulently during the flood. Due to restricted hydrological dynamics the waterbodies of the former floodplain were mainly inhabited by ubiquitous species.
Aquatic macroinvertebrate assemblages of two contrasting floodplains: The rhǒne and ain rivers, France
Authors: Castella E. , Richardot‐Coulet M. , Roux C. , Richoux P. 
Published: February 2007

AbstractThe study examines the relationship between floodplain aquatic macroinvertebrates and sector‐scale parameters such as geomorphology and history of regulation. The assemblages of six groups of invertebrates (Molluscs, Crustaceans, Ephemeroptera, Odonata, Trichoptera, and Coleoptera) were compared in various types of former channels from two contrasting but adjacent floodplain sectors: (1) the Jons sector of the Rhǒne River where successive meandering and braiding phases has left diversified fluvial forms in the landscape but where the main river is now embanked, and (2) the unregulated Ain River sector where the river is still actively meandering, although this process is being slowed by incision. The results demonstrate little difference in faunal composition between the two sectors but a significant difference in faunal structure. In the Rhǒne floodplain, there was a clear distinction between the faunal assemblages together with a high taxa richness at the scale of the sector (dominance of the beta diversity). In the Ain floodplain, the faunal assemblages were overlapping and the taxa richness was high at the sample scale (alpha diversity). Sector‐scale spatial patterns of the faunal assemblages along former channels were also distinct: between‐channel heterogeneity dominated in the Rhǒne, whereas within‐channel heterogeneity dominated on the Ain. These results stress the influence of geomorphological and historical determinants on the floodplain communities and, conversely, the relevance of macroinvertebrate assemblages for the assessment, at the landscape scale, of aquatic systems within the floodplains.
Composition and distribution of carabid communities along rivers and ponds in the region of upper weser (NW/NDS/FRG) with respect to protection and management of a floodplain ecosystem
Authors: Gerken B. , Dörfer K. , Buschmann M. , Kamps‐Schwob S. , Berthelmann J. , Gertenbach D. 
Published: February 2007

AbstractOn the basis of investigations on carabids along the Weser and some tributaries, ponds, and secondary habitats in gravel‐pits, the composition and spatial distribution of carabid communities are described: 132 carabid species were found in riverine habitats of the Weser floodplains near Höxter/Holzminden (FRG) and the relationship of selected species to grain‐size and coverage of vegetation are documented. Some typical carabid communities of mid‐European river ecosystems are present along the Weser, but the species and their few, mostly relic, habitats as well as secondary habitats in gravel‐pits are endangered. A long‐term and area‐oriented habitat management is necessary to protect and to develop the autochthonous carabid fauna.
The use of coleoptera (arthropoda:insecta) for floodplain characterization on the River Trent, U.K.
Authors: Greenwood M. T. , Bickerton M. A. , Castella E. , Large A. R. G. , Petts G. E. 
Published: February 2007

AbstractFollowing a long history of floodplain degradation, directly or indirectly as a result of river regulation, international attention is turning to the restoration of these ecologically important ecotones. One immediate problem is to assess the ecological value of different floodplain habitats. With reference to two floodplain sectors—one non‐regulated and one regulated—on the River Trent, U.K., this paper characterizes the dominant floodplain units using two families of beetles (Coleoptera: Carabidae and Staphylinidae). Five dominant habitat units, riparian, wetland, woodland, pasture, and arable, are clearly differentiated by both families using ordination analyses. Although the faunal assemblages of specific units within the two sectors have many similarities, the units within the regulated sector are more clearly differentiated, having larger assemblages of ‘describer’ species. It is suggested that the enhanced environmental gradients between units within this sector may be responsible for stronger faunal contrasts.
Differentiation between epigeic and hypogeic fauna in gravel streams
Authors: Bretschko G. 
Published: February 2007

AbstractThe ‘hyporheic zone’ is described. According to the classical definition, water below the sediment surface is groundwater and the hyporheic interstitial zone is part of the phreatic system. This ignores the vertical distribution of the epigeic benthic fauna. The uppermost layer of the sediment (bed sediments) of the hyporheic zone is dominated by epigeic faunal elements and is therefore part of the surface system. In contrast to hypogeic species, the depth penetration of epigeic species is limited. Possible explanations are discussed.
Structure of interstitial assemblages in a regulated channel of the river rhine (France)
Authors: Des Chǎtelliers M. Creuzé , Marmonier P. , Dole‐Olivier M. J. , Castella E. 
Published: February 2007

AbstractThe interstitial assemblages of the River Rhine were studied in the Rhinau sector (France). The studied area is located in aVegulated channel of the river, controlled by a hydroelectric dam. Twenty stations were sampled in September 1988. Ten litres of interstitial water were pumped at 50 cm depth in each station using the Bou‐Rouch technique. Interstitial waters were poorly oxygenated and the hyporheic fauna had three major characteristics: (1) microcrustaceans were dominant, (2) the insects were rare and (3) the stygofauna was absent. The richest stations were well oxygenated and did not correspond to any particular geomorphological features. These findings contrast with the situation observed on other large European rivers (Rhǒne, Danube) where the interstitial assemblages appear to be locally more diversified and rich in stygofauna.
Flooding frequency and invertebrate emergence from dry floodplain sediments of the river murray, Australia
Authors: Boulton A. J. , Lloyd L. N. 
Published: February 2007

AbstractRegulation of lowland rivers often alienates large areas of the floodplain, altering the natural regime of flooding frequency, duration, and magnitude. The extent to which such changes alter the productivity of river‐floodplain ecosystems and the contribution of aquatic invertebrates emerging from dry floodplain sediments is unknown. To examine this in a section of the River Murray in South Australia, fourteen replicate sods of dry sediment collected from four areas of the floodplain that had experienced different average flood recurrence frequencies (annually, 1 in 7, 1 in 11, and 1 in 22 years) were inundated in the laboratory, simulating flooding. Invertebrates emerging from the dry sediments were sampled with replacement 1, 2, 3, 7, 10, 14, 21, and 28 days after inundation, enabling comparisons of temporal changes in faunal composition and biomass. The greatest biomass and numbers of invertebrates emerged from annually‐flooded sods whereas sediments usually flooded once in 22 years yielded only protozoans. Large numbers of cladocerans and rotifers were recorded within two days of inundation whereas ostracods were not numerous until two weeks later. Heterogeneity in faunal composition and biomass among replicates probably reflected patchiness in microtopography and resting stage settlement, and variable hatching ‘strategies’. Although experimental conditions rapidly diverged from the natural situation over time because of the unrealistic constraints of enclosure, results suggest a potentially significant contribution by emergent invertebrates to the newly‐inundated floodplain foodweb. Reducing floodplain inundation frequency through regulation and flood mitigation probably severely reduces this reserve, removing a food resource for young fish and other predators.
Invertebrate communities of former southern moravian floodplains (Czechoslovakia) and impacts of regulation
Authors: Adamek Zdenek , Sukop Ivo 
Published: February 2007

AbstractThe natural hydrobiological conditions of southern Moravian floodplains have been drastically altered by regulation of the lower Dyje river and its tributaries. Natural floodplains were characterized by temporary pools and swamps, each inhabited by a typical community of aquatic invertebrates, and permanent water bodies (rivers and abandoned channels). Some aquatic taxa migrated onto ‘terrestrial’ localities during flood periods. Following regulation, floods were eliminated and most of the wet floodplain habitats disappeared, together with their typical species. The results of faunistic studies carried out in different permanent and temporary water bodies of the floodplains are reviewed. Altogether 188 taxa of planktonic and 206 taxa of benthic and semiplanktonic animals have been recorded. Of the planktonic community, rotifers (96 taxa) and copepods (41 taxa) have very favourable conditions for their development, especially in the spring. The main season for cladocera (53 taxa) development (summer) is less favourable due to the short duration of flooding (in flooded meadows) or poor oxygen conditions (in temporary pools with a high content of decaying organic matter). Among the zoobenthos, mainly facultative aquatic macroinvertebrates (larvae of insects) appear in these localities.
Impact of channelization on the mimmshall brook, Hertfordshire, Uk
Authors: Darby Stephen E. , Thorne Colin R. 
Published: February 2007

AbstractWater End, Hertfordshire, has been designated as a Site of Special Scientific Interest due to the presence of some of the most important swallow holes in southern England. However, the swallow holes are being infilled by sediment and rubbish, resulting in severe environmental deterioration. Sedimentation appears to have been accelerated by human disruption of the Mimmshall Brook catchment, within which the swallow holes are located. A study of the sediment dynamics within the Mimmshall catchment was undertaken to identify instabilities and sediment transfer dynamics in the fluvial system. Channelization is shown to be the primary cause of the sedimentation problem. It was found that channelization triggers sediment flux divergences which in turn necessitate channel changes to restore equilibrium. As nickpoints migrate upstream of channelized reaches, bed degradation increases bank height. This decreases the stability of the bank with respect to mass failure. Bank failures occur under ‘worst case’ conditions once the threshold of bank instability is crossed. Bank erosion and mass failures were found to be the major sources of sediment to Water End and it was concluded that bank retreat must be controlled if environmental deterioration at Water End is to be slowed or reversed.
Sediment transport and channel characteristics of a sand‐bed portion of the green river below flaming gorge dam, Utah, USA
Authors: Lyons Joseph K. , Pucherelli Michael J. , Clark Richard C. 
Published: February 2007

AbstractThe Green River is a major tributary of the Colorado River with a drainage area of 115 770 km2 in Colorado, Utah and Wyoming. The influence of Flaming Gorge Dam on sediment transport and the potential for future channel change were studied using comparative analysis of historical aerial photographs from 1952 to 1987 and geographical information systems, published sediment (1951‐86) and discharge (1965‐87) records, and sediment data collected during 1986‐8. Since the closure of the dam in 1964, new equilibrium channel widths were apparently achieved by 1974 in the reach 161‐279 km below Flaming Gorge Reservoir and by 1981 in the reach 465‐509 km below the reservoir. Recent high flows have resulted in an increase in average channel width in both reaches as measured on aerial photographs taken in 1986 and 1987. Sediment data from US Geological Survey gauges on the Green River and its primary tributaries and three sites established on the Green River for this study suggest that bed material sediment transport in the Green River has now attained a quasi‐equilibrium, with the river transporting just the load supplied to it. The potential for future channel changes exists, as evidenced by the response of the channel (i.e. channel widening) to the increased flows during 1983, 1984 and 1986. Future adjustments in channel characteristics should be limited to responses to changes in discharge and sediment supply and transport in the basin.
Ecology of the lower rhône after 200 years of human influence: A review
Authors: Fruget J. F. 
Published: February 2007

AbstractEmbankments of the last century and contemporary channelization and development of urban and industrial areas along the Rhone Valley have greatly changed the river. The impacts of these on three biological descriptors of the hydrosystem (benthic invertebrates, fish communities and aquatic birds) have been studied. A reduction in the morphological diversity of the regulated hydrosystem has caused a reduction in biological diversity. This system has become a slow potamic system as a consequence of the more uniform environmental conditions: the benthic macroinvertebrate fauna has become eurytopic and pollution tolerant, with very localized potamic species; fish communities are dominated by limnophilic cyprinids; and water bird communities are limited by the absence of typical species of fluvial areas, such as terns.
Channel change and flood events since 1783 on the regulated river tay, Scotland: Implications for flood hazard management
Authors: Gilvear D. J. , Winterbottom S. J. 
Published: February 2007

AbstractAn analysis of old maps and documentary sources reveals that major changes in river channel planform have occurred over the last 200 years on the River Tay system, Scotland, UK. Reaches showing natural river channel planform change, however, are relatively small and a stable planform is characteristic of many sections of the river. River planform instability appears to be controlled by channel bed slope, sediment load and the enhanced vulnerability of former river channel courses to erosion. Flood protection embankments built in the 19th and 20th centuries modified unstable multichannel wandering gravel bed river sections to narrower single‐channel reaches, with limited lateral migration. On the River Tummel, 20th century impoundment has caused further geomorphological change in response to clearwater erosion close to the dam and aggradation processes within the regulated river downstream, but isolation of the effects of impoundment from those of channelization are problematic. An examination of the geomorphic effects of a high magnitude flood event in 1990 and historical accounts of earlier large floods reveal that the 1990 flood was the third largest since 1800 in the study area. Despite river regulation and bank protection the zones naturally characterized by instability are still susceptible to planform changes causing flood embankments to be breached, channel shifts and development of gravel bars.
Channel response to large‐scale river training works: hunter river, Australia
Authors: Erskine Wayne D. 
Published: February 2007

AbstractExtensive river training works were undertaken on the upper Hunter River, Australia between 1956 and 1978 in response to rapid lateral migration and channel widening caused by a series of large floods between 1949 and 1955. River training involved artificial cutoffs, extensive realignment, structural bank protection works and tree planting. Channel length and hence sinuosity (ratio of channel length to valley length) decreased throughout each of six reaches located in the 78.9 km long study area as a direct result of the artificial cutoffs and realignment. Although the overall length reduction was less than 5%, one section experienced a 17% reduction. Localized channel straightening directly increased slope, decreased roughness and consequently increased flow velocity. The structural works have generally succeeded, converting an actively migrating stream into a laterally stable channel. Largely because of channel straightening and reduced sediment supply by floodplain reworking, the river has responded by eroding its bed by up to 1.1 m since the 1950s. Bed erosion preferentially removed the sand and fine gravel fraction producing an armour layer of coarse gravel. This armour layer halted further erosion by protecting the underlying fine material and is now only episodically mobilized by floods with return periods greater than 5.6 years on the annual maximum series. Unfortunately degradation was not predicted before the river training works were undertaken and it was only the fortuitous formation of the bed armour layer which prevented the degradation from becoming a major problem.
Vegetation, river management and land use in the dutch rhine floodplains
Authors: Jongman Rob H. G. 
Published: February 2007

AbstractThe floodplains of the lower Rhine are situated in a densely populated area of the Netherlands. Although they are used intensively the floodplains still fulfill important ecological functions. The lower Rhine is the downstream sedimentation zone of the River Rhine and its floodplains are characterized by river‐transported vascular flora originating from southern and eastern Europe. Using multivariate methods data from previously published work and field data on grasslands and former river beds have been analysed to determine trends in ecological changes. The consequence of continued sedimentation and decreased erosion is an increased drying out of the floodplains. Excavation and recultivation of formerly excavated land does not reverse the losses in flora and vegetation. Statistically there is a negative relationship between the characteristic flora and recultivated land. The natural transversal river gradient also disappears, together with its characteristic ecological diversity. Aquatic environments in the floodplains have been changed completely since regulation work started in the 19th century. Most former river beds have disappeared due to silting up. Data on short‐term vegetation succession confirm the long term analysis of map data.
Effects of diversion on the chemistry of a stream in Japan
Authors: Kagawa H. 
Published: February 2007

AbstractOn the upper reaches of the Ishite River, Japan the stream water is diverted completely at about 3 km above the Ishitegawa Reservoir, except under flood conditions. The chemical composition of the regenerated streamflow 2.4 km downstream from the diversion was determined 70 times during two years (1986‐7) to investigate the effects of the diversion on water chemistry. Factor analysis suggested that two main factors controlled the water chemistry. Factor 1 explained 45.7% of the total variance and was correlated positively with the concentrations of Ca2+, Mg2+, Na+, HCO− 3, SO2− 4 and Cl−, which seemed to reflect the leaching of dominant ions from the catchment soil. The factor 1 score was correlated negatively with the ecological ‘Ca‐Mg index’ (r2 = 0.912), a low value of which is necessary to avoid phosphorus enrichment by phytoplankton in the downstream reservoir. The diversion seemed to contribute to this purpose because the log flow‐rate value was correlated positively with the index (r2 = 0.730). On the other hand, factor 2 explained 10.2% of the total variance and was correlated positively with NO− 3 concentration and negatively with pH. Factor 2 was considered in relation to the partial pressure of dissolved CO2 gas in the stream water and appeared to be a complex biological factor that reflected CO2 production in the catchment soil and consumption in the stream.
Effects of dams and reservoirs on the hydrological characteristics of the lower drava river
Authors: Bonacci Ognjen , Tadic Zdenko , Trninic Dusan 
Published: February 2007

AbstractDuring the last 20 years numerous water supply, hydroelectric and other large structures have been built along the Drava River and in its catchment area in Slovenia, Croatia, Hungary and Austria. Their construction has greatly influenced the water regime of the Drava River, especially during low water periods. The changes in the low flow regime along the stretch from Varazdin (285 km) to its confluence with the Danube (0 km) are examined. The analysis includes changes in the water levels, discharges and the amounts of suspended sediment and bed load. The intensity of changes, the time of their occurrence and their trends are examined.
Dynamic stability in hydropsychid guilds along a regulated stream: The role of competitive interactions versus environmental perturbations
Authors: Camargo Julio A. 
Published: February 2007

AbstractTemporal alterations in the structure of hydropsychid guilds were studied along a regulated stream (Río Duratón, northern Spain) to examine the role of interspecific competitive interactions and environmental perturbations in determining species persistence. Discharge fluctuations of hypolimnial waters with a significant oxygen deficit were produced daily by Burgomillodo Dam. Under unregulated conditions (upstream sampling site), it is assumed that the coexistence of competing hydropsychid species is a function of species dominance (d') and resource limitation (R), as major causes of interaction strength among competitors, and the niche overlap (O) as a major cause of connectance among competitors, d' tends to increase with the number of subordinate species. Thus, and according to May's model of stability, a hydropsychid guild will tend to be unstable (by competitive displacement) if d'R(SO)0.5 > 1, where S is the number of competing species in the guild. The product d'R(SO)0.5 is used as a competition coefficient (β′). To facilitate the calculation of β′, the values of R and 0 are assumed to be 1 and 0.5, respectively. Riffle macrobenthic surveys were undertaken in June and December 1987, and in June 1988. Upstream from the dam, values of β′ were 0.599, 1080 and 0.656, and values of S were 7, 7 and 6. Downstream from the dam, β′ was less than unity during all sampling surveys, but S decreased at all downstream sampling sites (mainly just below the dam). Total density and total biomass were significantly higher downstream than upstream (except just below the dam). Hydropsyche pellucidula was dominant upstream, whereas H. siltalai became dominant downstream. Temporal variations in individual weights of H. bulbifera and H. exocellata downstream were different from those upstream. This fact is interpreted as a phenomenon of character displacement. It is concluded that interspecific competitive interactions upstream and environmental perturbations downstream determined species persistence in hydropsychid guilds.