bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulated rivers in the United Kingdom
Authors: Petts Geoffrey E. 
Published: February 2007

AbstractThis paper identifies the principal regulated rivers in Britain and summarizes their physical and ecological characteristics. Virtually all major rivers in the United Kingdom are shown to be regulated directly or indirectly by mainstream impoundments, interbasin transfers, pumped storage reservoirs, or groundwater abstractions. Flow records for sixty per cent of all gauging stations are significantly affected by flow manipulations. Three phases in the development of river regulation are identified: firstly, the development of direct supply and compensation reservoirs from 1840; secondly, the development of large dams and large‐scale interbasin water transfers from 1890; and thirdly, the modern era of multipurpose river regulation that began in 1965.Any assessment of the environmental effects of river regulation must consider the spatial variation of natural river systems throughout the U.K., climatic changes, and the cumulative effect of river regulation and other impacts over an historic timescale. Today, the rivers of the U.K. are shown to have an underlying character that reflects the marked climatic, geologic, and topographic differences between the upland north and west, and lowland south and east; differences in part that relate to their different histories during the Pleistocene. However, many rivers show the effects of human impacts that began about 5000 years ago. Most rivers have experienced changes since about 1930 consequent upon afforestaton, land drainage, and channelization. These, together with short‐term climatic changes, make defining ecological impacts of river regulation problematic. Pollution has had the most dramatic effects. Nevertheless, it is suggested that new concepts of environmentally sound river regulation could lead to the restoration and even enhancement of rivers in the United Kingdom.
River regulation in the United Kingdom: An historical perspective
Authors: Sheail John 
Published: February 2007

AbstractThe beginnings of direct river modification in the U.K. are traced back to the 1st century A.D. when works were undertaken for land drainage and transportation. After the Roman period river works were widespread, there being more than 5,000 water‐mills by 1086, but of small scale until the 17th century. Impressive drainage schemes were supplemented from the end of the 18th century by the construction of numerous small dams for water supply and to provide compensation water. Severe pollution during the mid‐19th century led eventually to an organized system of river management. By 1900 the era of large dam buildings and large (> 1000 km) inter‐basin transfers had begun. The regulation of rivers in the U.K. has been subjected to much public scrutiny and debate, more so than the development of any other resource. However, the problems being encountered in river management today are shown to be embedded in the history of water resource development.
River regulation: A regional perspective—Northumbrian water authority
Authors: Johnson P. 
Published: February 2007

AbstractIn the past three decades, river regulation has become a key component of integrated water management in the U.K. water industry. This paper reviews the concept and operation of river regulation with reference to the Northumbrian Water Authority region. The role of regulating the Rivers Tyne and Tees is considered within a regional perspective. Regulation began on the River Tees in 1965 and the regulation potential of the region was completed with the Kielder Scheme on the River Tyne in 1981. During the year, regulation in Teesdale is largely determined by abstraction demands. Hydropower releases from Kielder have an important effect on the River Tyne. The control patterns and priorities are discussed in general and specifically with regard to statutory and other requirements. These include minimum maintained flows, drought orders, riparian and amenity interests, water‐quality, and ecology. Flexibility and cooperation are key concepts; the management of water‐quality remains arguably the major problem.
Regulation of the River Thames. A case study on the teddington flow proposal
Authors: Sexton J. R. 
Published: February 2007

AbstractThis paper discusses the inception, development and assessment of one specific scheme: the Teddington Flow Proposal. The Proposal modifies existing flow regulation policy to provide an additional 170 Ml d−1 for supply. After extensive studies concerning water quality, water levels, and the potential effects on ecology, navigation, recreation and amenity, no significant detrimental effects have been identified.The overall effect of the Teddington Flow Proposal would be beneficial. The river environment would be improved in major drought years, when the most serious effects on the river would otherwise occur. This more than offsets a small deterioration in certain factors in some non‐drought years. The biggest benefit will be to the five million people living and the even greater number working in London who will have less frequent and less severe restrictions on their water supply with virtually no consequential increase in their water charges.
Fish and fisheries of regulated rivers in the UK
Authors: Mann R. H. K. 
Published: February 2007

AbstractThis paper examines the historical and recent influences of river regulation on fish populations and fisheries in Britain. The construction of a series of canals and interconnecting waters during the 18th and 19th centuries facilitated the spread of some species between catchments. These slow‐flowing habitats allowed many lowland species to thrive and this is reflected today in the fish community structure in some rivers.The problems of barriers to the movement of migratory species imposed by dams and weirs and the efficacy of compensation measures are discussed. The latter embrace fish passes, adult fish and smolt transport, and stocking. Potential problems for the future include the disruption of the homing of salmon to their natal rivers caused by transfers of water between catchments.River basin management in Britain attempts to reconcile the water resource requirements of fisheries with those of other water users. This can be seen in the practice of Regional Water Authorities to include ameliorative measures in many of their land drainage and flood prevention designs. However, more research is required on the long‐term problems and benefits of these and other river regulation schemes on resident fish populations.
Fish populations of a small lowland channelized river in England subject to long‐term river maintenance and management works
Authors: Swales Stephen 
Published: February 2007

AbstractFish populations in the River Perry, a small lowland channelized river in England, were affected by long‐term river maintenance and improvement works. Habitat diversity at two ‘old channelized’ sites was low compared with a downstream ‘partially channelized’ site and an unmodified site, where natural river features such as the pool‐riffle pattern were more apparent. The fish community was low in diversity at all sites, with two running‐water cyprinids, dace Leuciscus leuciscus (L.) and chub Leuciscus cephalus (L.), being the dominant fish species. Relative species composition varied between sites, with dace predominating at the ‘old channelized’ sites and chub increasingly dominant at the ‘partially channelized’ and unmodified sites. Population density and biomass estimates of dace were similar at all sites, but chub were up three times more abundant at the ‘partially channelized’ and unmodified sites than at the ‘old channelized’ sites. Populations of dace and chub at the ‘old channelized’ sites contained a higher proportion of small fish than populations at the downstream sites, which exhibited a more balanced population structure. The growth rates of both dace and chub varied between sites. Low recaptures of marked dace suggested a highly mobile movement pattern while higher recapture rates of chub, particularly at the ‘partially channelized’ and unmodified sites, seemed to indicate a more sedentary activity pattern. The conclusion of the study is that long‐term river maintenance and management works may delay the morphological and biological recovery of lowland channelized rivers.
The role of riparian woods in regulating nitrogen fluxes between the alluvial aquifer and surface water: A conceptual model
Authors: Pinay G. , Decamps H. 
Published: February 2007

AbstractConceptual models are proposed to explain nitrogen fluxes in the soils of riparian zones in relation to the different modalities of water logging and nitrate inputs. Non‐submerged, temporarily submerged, and always submerged, sites are considered in both winter and summer. It is shown that capacities for epuration are elevated for nitrate loads from the alluvial aquifer during the lateral transfer of water from agricultural land to the river through the riparian zone. About 30 m of groundwater flow under the riparian wood studied is sufficient to remove all nitrate. Denitrification rates up to 50 mg N2 per m2 per day were observed in the field, but a potential for more denitrification exists. The efficiency of the riparian woods as natural filters regulating nutrient transfers to the river deserves more consideration in river management.
A mathematical hydraulic model of the River Nene ‐ A canalized, and heavily controlled river
Authors: Williams J. J. R. , Fawthrop N. P. 
Published: February 2007

AbstractThe paper describes a mathematical hydraulic model of the River Nene in East Anglia, England. This river, which is typical of many in that predominantly flat region, is canalized and subsequently heavily controlled. The routing model has been developed in order to investigate the effect of improvements that could be made to the river to reduce the frequency of flooding. The model is in its final stage of development and results are presented of a flood that was monitored in March 1982.
Radial stem growth of coniferous trees near Swedish reservoirs
Authors: Grelsson Gunnel 
Published: February 2007

AbstractTree ring data are presented for two species of coniferous trees growing close to the margins of two contrasting types of reservoir, an annually regulated one (bordered by Picea abies) and a daily and weekly regulated one (Pinns sylvestris). The radial growth‐ring data for the periods before and after damming and regulation were compared utilizing a mathematical growth model. The basic hypothesis was that changed water‐level conditions due to hydroelectric development would change the groundwater levels and associated factors and thus affect tree growth. For spruce trees growing along the long‐term (annually) regulated reservoir, no significant differences in growth between the pre‐damming and post‐damming periods were found; nor was any correlation found between tree growth and the duration of the period of high‐water level in this reservoir. For pine trees growing along the short‐term (daily and weekly) regulated reservoir a significant increase in the variation in growth was found following regulation, but only at the lowest levels. No other significant differences in tree growth between the periods before and after regulation were found.
The benefits and costs of allocating space in an existing reservoir to river regulation
Authors: Higgins Roger J. 
Published: February 2007

AbstractSubsequent to the selection of design capacity and the construction of a storage reservoir, water demands, valley land‐use, and economic constraints may change and the reallocation of storage space in an existing reservoir may become desirable. The benefits of reallocating space to flood mitigation are the equivalent annual flood damages averted, while the costs arise from water shortages which would not have occurred if space had not been reallocated. These benefits and costs can be quantified for a particular region and the optimal airspace provision calculated. In a case study area, reallocation of part of the storage volume was justified, while excessive reallocation would result in significant net costs to the region. The optimum airspace allocation was not sensitive to the value assigned to water. The procedure used here could be applied to other river valleys, where the solution would be dependent on the intensity of land‐use, as it influences both potential flood damages and the costs of water shortages.
Deterministic modelling of vertical circulation in shallow lakes and reservoirs
Authors: Falconer R. A. , Cox I. C. S. 
Published: February 2007

AbstractThe paper describes the development and application of a two‐dimensional breadth averaged deterministic mathematical model to determine the wind induced vertical circulation and mixing in shallow lakes or impoundments. Such models are increasingly being used by water engineers and scientists so that water supply lakes and reservoirs can be managed and operated more efficiently, particularly in connection with environmental and ecological considerations. The model includes the solution of the two‐dimensional form of the mass and momentum conservation equations, with particular emphasis being placed on the inclusion and representation of the bed friction, wind shear stress, and the turbulent mixing process. The pressure field was determined from the depth averaged form of the governing differential equations, with the complete set of equations being expressed in an implicit finite difference form for solution. Results from the model were compared with analytical solutions for two idealized flow fields, with good agreement being obtained between both sets of results. Simulations of wind‐induced circulation were then performed for two U.K. reservoirs, with the results obtained being in keeping with the published results of other researchers.
Influence of regulation on environmental conditions and the macroinvertebrate community in the upper Colorado river
Authors: Rader Russell B. , Ward James V. 
Published: February 2007

AbstractThe influence of stream regulation on environmental conditions and concomitant alterations of macroinvertebrate community structure was determined from field studies conducted from September 1981‐June 1983 at three sites on the upper Colorado River. Site 1 (reference site) was located above Granby and Shadow Mountain Reservoirs, a deep‐release storage impoundment, whereas sites 2 (regulated site) and 3 (recovery site) were located 0·4 and 4·0 km, respectively, below the dam.Although macroinvertebrate diversity was reduced at the regulated site compared to both the reference and recovery sites, the number of taxa (43) was considerably higher than values reported from studies of other regulated streams in the Rocky Mountains. Macroinvertebrate mean annual density in the regulated site was twenty times higher than at the reference site and slightly higher than the recovery site. The regulated site was characterized by the absence of heptageniid mayflies, reductions in stoneflies, caddisflies, shredders, and predators, and high densities of Baetis spp., Ephemerella infrequens, chironomids, and non‐insect taxa. Many of these faunal changes are attributed to alterations in the temperature regime induced by regulation and to changes in the source and temporal sequencing of organic detritus. Although the number of annual degree days was actually greater below the dam than above the reservoir, other components of the thermal regime was severely altered by regulation. At the regulated site the primary source of coarse organic detritus was autochthonous (decaying algae) with a vernal pulse, in contrast to the typical autumnal pulse of allochthonous leaf litter. There was no evidence that the greater substrate permeability and flow predictability below the dam directly influenced the reduction of species.
Seasonal variation in the composition of the drift below a peaking hydroelectric project
Authors: Layzer James B. , Nehus Timothy J. , Pennington Wendell , Gore James A. , Nestler John M. 
Published: February 2007

AbstractWe used 0.5 m diameter nets to sample the drift downstream from a peaking hydroelectric project on the Caney Fork River, Tennessee. The relative contribution of the terrestrial, lentic, and lotic environments to stream drift varied seasonally. Stream benthos (primarily Chironomidae and Lirceus fontinalis) occurred in the drift throughout the year; however, their relative importance varied seasonally. Daphnia sp. from the reservoir also occurred in the drift year round with the highest densities in fall and spring when they were the predominant species in the drift. In summer, terrestrial insects apparently utilized exposed portions of the river bed during periods of no power generation. In June as the river stage increased following initiation of generation, adult terrestrial insects became a major component of the drift. Threadfin shad (Dorosoma petenense) dominated the biomass in the drift during December. Although the importance of stream benthos to fish populations is generally recognized, the contribution of the terrestrial and upstream reservoir environments to the forage base in the tailwater may also be important and should be considered in developing management strategies for tailwater fisheries.
Assessing the impacts of stream regulation in the flathead river Basin, Montana, U.S.A. I. Simulation modelling of system water balance
Authors: Hall Charles A. S. , Jourdonnais Jon H. , Stanford Jack A. 
Published: February 2007

AbstractA Fortran‐based simulation model was written to predict water movement into and out of Flathead Lake. Since tributaries, the lake proper and downstream flows were either freeflowing or regulated by hydroelectric dams, it was necessary for the model to adjust simulated, regulated flows to account for predicted natural flows. Empirical input to the model consisted of daily discharge data or statistical summaries of data sets for an 80+ year period of record for gauging sites on major tributaries, the lake and its outlet river. The model produces graphical output of empirical observations or simulates lake levels and riverine flows on the basis of any selected period of the record. The model was successfully used to evaluate the feasibility of various water management scenarios to enhance or protect fish and wildlife and also permit various hydropower production quotas.
Framework for control of dynamic ice breakup by river regulation
Authors: Ferrick M. G. , Mulherin N. D. 
Published: February 2007

AbstractIn this paper, we describe and classify the entire range of ice breakup behaviour, from thermal to dynamic, to provide order to this complex process. The theory and model of Ferrick et al. (1986b) are refined, building on the concept of an intrinsic relationship between river waves and dynamic ice breakup. A force balance is developed for a common dynamic breakup behaviour. Empirical criteria that quantify the resistance to breakup of an ice cover are obtained from a case study and compared with published values. Sensitivity studies of ice breakup with the completed model demonstrate insights that follow from the theory presented, and the intuitive nature of the results. This framework for understanding river ice processes provides the option for ice management by river regulation, and we focus on the potential for control of ice breakup. The concept of controlled breakup involves a release of water from a dam that moves the ice downstream of locations with a high potential for damages during breakup. The abrupt, short‐duration characteristics of the controlled release, patterned after those of unregulated river breakup, minimize both the volume of water required to cause breakup and the water levels at breakup. The open water created by the breakup collects heat that increases the rate of melting of the ice. The benefits of successful regulation include the prevention of flooding, minimum erosion and decreased potential for ice damage to structures during breakup without adverse affects on the environment.
The effect of stream regulation on the physico‐chemical properties of the palmiet river, South Africa
Authors: Byren Barbara A. , Davies Bryan R. 
Published: February 2007

AbstractThe effect of regulation, by multiple impoundment, on ‘discontinuity’ (recovery) ‘distances’ (sensu Ward and Stanford, 1983) for various physico‐chemical attributes of the Palmiet River (a short, steep gradient, cool temperate, acid, low‐nutrient system) was investigated. Physico‐chemical features were measured monthly, from February 1986 to August 1987, at 11 sites along the river, but concentrating on two zones: one below an upper‐reach impoundment, Nuweberg Dam, and one below a middle‐reach impoundment, Arieskraal Dam. Median total suspended solids, nitrates, nitrites and ammonium all increased below both dams with varying levels of ‘recovery’. Median spot temperatures, pH and alkalinity increased below Nuweberg, but decreased below Arieskraal Dam, whereas the converse was true for soluble reactive phosphate. Nuweberg had no effect on conductivity and total dissolved solids, while Arieskraal caused a slight decrease. The river remained well oxygenated down its length.Distinct seasonal variations were recorded for: flow rate, with flow reversal below Nuweberg and flow constancy below Arieskraal; temperature, with seasonal shifts and dampening of annual temperature range below both dams; alkalinity, with seasonal shifts below Arieskraal, and nitrites and nitrates, but not for any other attributes. At least partial recovery was noted in all cases, but in some instances, recovery was incomplete to the estuary. The implications of such alterations, for invertebrates, in terms of reduction in habitat diversity as well as for food supply must be considerable and studies are currently under way to determine community structure and diversity.
Effects of an upland impoundment on structural and functional properties of a small stream in a basaltic plateau (golan heights, Israel)
Authors: Tuch Koby , Gasith Avital 
Published: February 2007

AbstractThe aim of the study was to evaluate the impact of an upland storage reservoir, typical of the series of reservoirs in the Golan Heights basaltic plateau, on structural and functional properties of the downstream ecosystem, in the vicinity of the reservoir, shortly after damming.The effect of impoundment on water quality conditions may be divided into winter‐spring, and summer periods. In the former, the impoundment seems to lengthen the period of flow of runoff quality water. This is evident by the elevated winter and spring turbidities and the higher concentrations of suspended solids below the reservoir. In summer, water quality below the reservoir is controlled by the consequences of stratification in the reservoir. The hypolimnial release results in depression of the maximal temperature and narrowing of the daily and seasonal temperature variations. It supplies water enriched in nutrients and low in oxygen, suspended solids and turbidity. The macroinvertebrate community responds to impoundment in density changes and shifting of dominance. We hypothesize that the thermal effect of hypolimnial release from warm monomictic reservoirs on the invertebrate community of warm streams will differ from an equivalent thermal change caused by cold dimictic reservoirs in cold, temperate zone, streams.The effect of impoundment on functional properties of the ecosystem are most pronounced. The rate of production of benthic algae biomass below the reservoir increased by more than two orders of magnitude, but the effect diminished downstream. The rate of processing of plant material below the reservoir was lower than above the reservoir. Further investigation is needed to clarify this effect. Changes in reservoir operation are recommended to diminish the effects of impoundment.