Current Projects (national funded projects)

On the basis of national information provided by representatives from Austria, Finland, France, Germany, Great Britain, Norway and Switzerland, this appendix describes the national funded running and planned projects to be a part of this Action. The projects described are not all approved for funding by national funders, but as far as possible confirmed by the time of writing.

Habitat modelling as a tool for the development of a river restoration concept at the Traisen River

This project uses the latest available technology in habitat modelling for the development of a river restoration concept at the Traisen River. We establish habitat suitability indices for 4 target fish species (juveniles, adults and spawners) and sample the available habitat with respect to flow velocity, water depth, substrate and cover at 4 different flows. The models will predict usable habitat for different flow and morphology conditions.

Within this project we develop a new habitat modelling approach (HARPHA) including multivariate habitat models based on logistic regression analyses. These new approaches accompanied by a comprehensive project database on physical and biological habitat information will function as an essential basis for the intended analyses of the planned COST action.

LIFE Nature project "Living Space of Danube Salmon"

The LIFE Nature project "Living Space of Danube Salmon" aims at specific measures to improve the habitat quality under the conservation obligation to directive 92/43/EWG for one of the most threatened fish species of Europe, the Danube Salmon (Hucho hucho). The project area includes the middle and lower section of river Pielach, the lower section of river Melk and the lower section of river Mank, which is the most important tributary of river Melk. The Danube salmon populations are highly dependent on spawning areas of the project area, which shall be connected with the Danube. These populations suffer from the disconnection of their traditional spawning areas, which are situated in the tributaries Pielach, Melk and Mank. Objectives are the opening of river continuum and connection of rivers with the stream reach of Danube, the improvement and conservation of the last dynamic reaches of Pielach (meandering sections) and the control of project success with a monitoring program. The HFA-BOKU is integrated in the strategic planning of the project and responsible for the ecological monitoring programme.

Benefits for the planned COST action will encompass information on habitat and migratory requirements of Danube salmon and other threatened fish species.

Assessment of the ecological efficiency of habitat restorations at the Leitha und Drau River

This project focuses on the evaluation of habitat improvement measures at a rhithral and a potamal river in Austria. Within the frame of ecologically orientated river management programmes a number of Austrian rivers has received habitat improvements but none of these projects has been evaluated with respect to ecological benefits yet. This project aims to analyse habitat restoration measures at two rivers of different nature by both physical habitat mapping and biological monitoring programmes.

The benefit for the COST Action: The project will provide new information on habitat use and requirement of indicator fish species that represent an essential basis for comparative analyses of various habitat modelling approaches.

Upper Salzach Stream Care Plan, a compromise between improve flood protection and attain near-natural ecological conditions

With a total length of 225 km, the Salzach River drains a catchment of 6734 km². The study site of the 5^th – 6^th order alpine stream has a total length of 60 km (catchment 1400 km²). Glaciers cover around 10 per cent of the catchment. Hydrological classification corresponds with a nivo-glacial discharge regime with a very strong annual character. The heavy modified river within the Oberpinzgau flows through a monotone canal-like channel with a correspondingly degraded aquatic community.

The main goal of the project, which took into account the potential effects of conventional river engineering measures, was to find out a compromise between the need to improve flood protection and the desire to attain near-natural ecological conditions. Thus, the ecologically oriented Upper Salzach Stream Care Plan represented an optimal response to several use demands.

A coordinated study of historical data and comparative stream analyses has been carried out, describing the potential condition of the upper Salzach River. The potential morphology of the stream course has been derived from historical information.

Rivers are subject to self-steering dynamic processes in the lapse of time. Single historic inspections only show the situation at the moment within river-history. Within the study, the river history of upper Salzach is documented over more than thousand years. Out of this, the potential stream course is re-enacted. Because of the lacking of reference reaches on the river itself, the potential riverbed morphology has been established by studying and evaluating reference reaches on comparable sections of other rivers of the same type.

For classifying comparable rivers, cluster analyses were used for a river typology, based upon morphological, hydrological and hydraulic parameters covering the complete scaling range. As a result, comparable rivers from 3 different types amount to a total of 18 river stretches. Nature like reference reaches within these rivers are selected for further analysis of the riverbed morphology. Measured physical conditions at reference rivers were compared with analyzed conditions from the current state of river Salzach.

Results from the deficiency analysis for the present morphological conditions of Salzach River form a section of the interdisciplinary definition of the model. Thus, the determination of idealized reference conditions from deficiency analysis combined with historical data was to widen up the riverbed by 20 to 100 % of existing river width, depending on river type. Possible effects on the riverbed and on the floodwater protection due to suggested construction measures along the river were shown for a prediction period of 60 years. The sediment flow analysis was performed with numerical simulations.

Further goals are to establish a long-term guiding view out of abiotic and biotic base data (flood protection & river restoration measures).

The benefit for the COST Action: Within the project work 12 nature like reference river sites and 6 river sites of regulated Salzach conditions are analyzed. Deficiency analyses out of comparisons of morphometric and hydraulic data of the Salzach river sites with nature like situations in combination with biotic data analyzes (benthos, fish) will be done within construction work of the river specific guiding view.

The benefit for the COST Action: Raw data (biotic and abiotic) for river reach scale are available for further habitat analyzes. A comparison of data collection strategies for medium and large rivers out of 3 different river types (stretched, oscillating, and meandering) will be done within COST Action.

Successful river restoration within the urban area of Salzburg shown at river Alterbach

Both flood protection and improving ecological conditions were the goals of a river restoration project on the ALTERBACH river, a 3^rd order river within the city of Salzburg. Based on biotic and abiotic characteristics, an interdisciplinary monitoring project demonstrated that the restoration measures increased habitat availability at the micro and meso scale. The analyses demonstrated the degree to which near-natural habitat conditions can be achieved while providing protection from a 100-year flood.

The benefit for the COST Action: Very detailed biotic and abiotic database for further analyzes at a restored small 3^rd order river within the urban area of the city of Salzburg is available. Morphometric and hydraulic data in micro and meso scale are available over a period of 5 years. Biotic reaction (fish species, biomass, abundances and composition of macrozoobenthos) caused by changes in habitat availability as a result of restoration works and self steering processes within the river site are analyzed. Data are available for further analyzes of comparison of methods and models.

Long term river monitoring at Schwechat river

Transport and deposition processes of sediment over the time period of 40 years are evaluated at Schwechat River, a 5^th order natural meandering river. The main goal is the documentation and analysis of self-steering changes of the river reach, the bed morphology and the habitat composition. Analyzes will yield in a river specific guiding view for a 5^th order meandering river type with a pluvio nival, winterstrong discharge regime.

The ongoing data collection takes place within the scope of hydrometric field works, a practical training of students. Data collection in micro and meso scale (river morphology, hydraulics, bottom near currents, mean currents, sediment distribution, etc) within a 1.5 km long natural river site (natural monument) is done yearly since 1995 including a 100 years flood event in 1997. Self-steering processes in changes of the river reach is documented and analyzed by using air view pictures since 1958.

For further restoration projects of the channeled downstream river stretch, the need for riparian property in order to create room for a meandering channel can be derived.

The benefit for the COST Action: Detailed abiotic data (yearly) from a natural meandering 5^th order stream are available over a period of 5 years for further habitat analyzes. New strategies out of COST Action program will be tested within river site. Developments of instrumentation techniques for field data collection will be tested and compared with experience out of our standard measurement equipment and techniques. Results will be comparable with existing data, collected by using existing Austrian standard methods.

The river site is prepared for workshops (GPS Base, Total station reference points, maps, etc).

Development of a habitat-modelling framework for the quantitative analysis of fluvial ecosystems

The aim of the project was to develop a new two-dimensional habitat model with which to (1) describe more reliably the ecological phenomena occurring in aquatic habitats, (2) study the effects of habitat alterations on riverine systems, and (3) evaluate the effects of flow regulation. As a result, a habitat model (FISU) based on a two-dimensional hydraulic model and geographical data was developed. The model includes, e.g., a new curvilinear anisotropic interpolation method for processing field data. The automated data processing methods applied save time needed for modelling and field work, and the two-dimensionality of the modelling produces more accurate flow estimations than the more traditional one-dimensional models presently in use. In future, further advances to the data processing, interpretation of biological data, and testing new flow models (3-D-models, etc.) will be developed.

The benefit for the COST Action: This project will increase the knowledge on the development of hydro-ecological models, field data sampling methods, and data management.

Evaluation of habitat enhancements conducted in northern rivers previously used for log drives: habitat modelling approach.

47 sections in 15 channelled streams are modelled with EVHA in order to assess the habitat enhancements, which were carried out to increase the heterogeneity of the habitat. Study design is based on before-after enhancement comparisons. In addition to the habitat modelling, the litter retention capacity of the streams is measured by a ‘leaf test’, and the fish densities are monitored by electric fishing.

The benefit for the COST Action: This project will give an example how to apply hydro-ecological modelling to the assessment of habitat enhancements in fluvial systems.

Habitat preference criteria for lotic fishes

The project emphasises spatial relations between fish, benthic macroinvertebrates and stream habitat in seasonally changing lotic environments by integrating biological realism into habitat modelling.

The aim of this research project is to determine the habitat preference criteria of some important riverine fish species (brown trout, grayling, salmon, land-locked salmon and sculpin), and to examine the possible changes in these preferences caused by fish interactions. Fish of different size and age are located in the study rivers during different seasons by means of electric fishing, diving or telemetry. The habitat used by the fish is related to the habitat available to produce habitat preference curves for the most important instream variables (e.g., depth, velocity and substrate). The generality of the preference indices is tested in other rivers. The patterns observed in the field, as well as the effects of biological interactions (e.g., competition, predation and food availability) on the habitat selection of fish, are studied experimentally in laboratory and semi-natural flumes.

The benefit for the COST Action: This work will give insights on the role of both physical and biological factors in fish habitat use and preference in spatially and temporally variable habitats.

Fish stocks in large hydropeaking rivers: Measuring the habitat availability and habitat use.

This project examines the fish stocks and their responses to changes in water flow in a large hydropeaking impoundment in the River Oulujoki. Advanced technology (differential geopositioning, ADCP, echo sounding, ground penetrating radar) is used to measure the bottom topography, water velocities and depths in the whole 8 km long reservoir. A physical habitat-model is used to simulate different flow situations. Fish positions are determined using echo sounding in open water and electric fishing near shore. Simultaneous test fishing to echo sounding is carried out to identify the species present in open water. Additionally, telemetry is used for specific purposes: (1) to assess the habitat use (preferences) and movements of adult pikeperch during different seasons, and (2) to measure the short-term responses of roach, the most common fish species in the reservoir, to changing flow. The duration of the study is from 1999 to 2001 and the annual total costs are ca. 40 000 Euro.

The benefit for the COST Action: This project will increase the knowledge on the application of hydro-ecological models, advanced field data sampling methods and data management in a large fluvial system.

Habitat enhancement in small streams: assessing the effects on habitat quality and salmonid production.

The goal of this project is to assess the importance of small streams as production areas of salmonids, and the influence of habitat enhancement on the fish stocks. Six small channelized streams were selected for a study on brown trout, and two for landlocked-salmon. Each stream contains three study sections. The streams are stocked with underyearling fish of the study species every autumn. After three years of monitoring (fish stocks, benthic invertebrates, drift, temperature, water level changes etc.) half of the streams are enhanced and the rest remain as control rivers. After restoration the monitoring continues for three years in order to evaluate the impact of restoration. Habitat modelling is applied to assess the amount of suitable habitat for salmonids before and after restoration.

The benefit for the COST Action: Due to its study design (BACI) and long duration, this work is unique in providing data for the spatial and temporal validation of hydro-ecological models, fish habitat requirements, and interactions in and between different trophic levels.

5M7 fish-mesohabitat model

The 5M7 fish-mesohabitat model is very recently developed and not yet published. It has been developed for fish investigations in the Durance River. It calculates preference coefficients related to mesohabitat prismatic irregular network decomposition of fishing environment. It can provide a population bio-energetic analyse of taxa adaptation strategy to shortage of hydrophysical environment. It also has been used to evaluate population dynamics in relation to the flow regime and hydrology.

We are still developing the 5M7 model to calculate mesohabitat preference coefficients on the Durance River to describe the fish habitat links, and to evaluate the ecological impact of the observed regulated flows especially for the nase (Chondrostoma nasus). Bioenergetic species ² trajectories² in 3D representations using individuals length, depth and velocity are linked with local hydraulic variables. This allows highlighting adaptive strategies of large individuals to the limiting physical conditions as in case of the barbel (Barbus barbus).

The benefit for the COST Action: New innovative modelling techniques will be developed and ready for testing by the scientific community. After testing and eventually improvements, the new tools can be available to the public as operational tools through this COST Action.

3D hydraulic model associated to Digital terrain modelling to provide better entries for habitat simulations

Cemagref are developing a modelling tool based on a digital terrain model applied for habitat modelling. SINTEF and NTNU are developing a habitat model based on the three-dimensional hydraulic model SSIIM and field investigations on habitat use, topography and hydraulic parameters for evaluation. The tools of Cemagref and SINTEF will be linked together, tested and developed further for applications in the current research programs at each institution.

Topographical description of rivers will be made with vertical density increasing with terrain complexity (adapted from geodesy techniques). Depending of experiment objective, polygons of homogenous area of substrate, vegetation or others can be described by topography. The digital terrain model is generated using curvilinear algorithm for interpolation. The grid process of both field points and interpolated points produces finite elements with triangular basis, equidistant cross-sections and longitudinal profiles can also be generated. Verticals, lines, polygons and prisms describe the topology of the model. The results will be used for input data to the SSIIM model and the habitat model at different scales from reach to microhabitat.

The benefit for the COST Action: New links between existing models will be made available. Both modelling groups in Norway and France have individual experience in modelling, but the link will benefit both groups and bring added value tp current research projects.

Hydraulic and morphologic simulation for habitat prediction in river systems

Development of improved hydraulic and morphologic simulation tools for patterns of physical parameters that are used for habitat simulations for fish and macrophytes within the simulation model CASIMIR. The new tools within CASIMIR are developed and calibrated from data from several river systems in Germany. Dynamic instream flow regulations are implemented in some of these river reaches, consequences for habitat quality is simulated and biologic response evaluated for validation of the predicted fish populations.

The benefit for COST Action: Development of improved simple and robust hydraulic simulation techniques for midland rivers. Determination of ecologically relevant physical patterns for fish species. Technical solutions for dynamic instream flow regulations and predictions of ecological impacts will be developed.

Long term investigation of biological integrity of a river influenced by construction and operation of a small Hydropower plant

The project is a long-term investigation of a river affected by a newly constructed diversion type hydropower plant to investigate long-term ecological effects and to validate the simulation model CASIMIR that was used to predict habitat suitability for various fish and benthic species.

The benefit for COST Action: Long term validation of the predictive tool CASIMIR

ÖKOSTROM in Collaboration with EAWAG (Swiss Federal Institute for Environmental Science and Technology, Limnological Research Centre)

The aim of the 2 year (1998-2000) pilot project is to develop an eco-label for hydropower plants. The pilot project is conducted in the Val Blenio at the river Brenno and several tributaries with a system that includes 3 hydropower plants with 2 large reservoirs and altogether 22 intakes. The valley‘s riverine ecosystem has been influenced over the last 40 years. Within the pilot project an evaluation procedure is to be developed that should suggest mitigation measures within the system to improve ecological sustainability. Measures include construction as well as operational management of the plants and compensation measures. Our part was to develop habitat simulation tools to be used for instream flow regulations.

The benefit for COST Action: The development of new Fuzzy approaches for fish and the validation of existing benthic habitat functions derived for northern Alps probably not applicable for southern Alps, will be carried out. Development of new hydraulic modelling techniques for steep mountain streams with very high roughness will be of interest. Reach based instream flow results will be transferred to river basin management strategies.

Environmental Impact Assessment including Instream Flow Investigations for 2 Hydropower Plants in the Rivers Inn (Bavaria) and Lenne (Ruhrgebiet).

The objective of both studies are new instream flow regulations in hydropower affected river reaches. The simulation model CASIMIR has so far mostly been applied in shallow rivers. In both, Inn and Lenne, water depths of several meters occur and measurement techniques as well as evaluation procedures of the model must be adapted to that. Whereas in the Inn large salmonids are the most important target species, in the macroinvertebrates must be considered as well. Therefore, further development of preference data and hydraulic simulation tools especially in deep water will be developed within these projects.

The benefit for COST Action: The project will give more information on deepwater preferences and deep-water measurement techniques to be used in other European streams.

Ecologically Acceptable Flows Phase III

The determination of Ecologically Acceptable Flows and River Flow Objectives is central to current water resource management in England and Wales. There is an increasing need to be able to assess the impact of future water resource developments on the environment. Modelling of instream physical habitat is the main operational tool used in England and Wales to undertake this assessment. There is a key requirement for such operational methods to be quantitative and predictive. Furthermore there is an increasing need for such methods to be demonstrably robust and authoritative.

This project is a three year study to test and validate physical habitat modelling in four target catchments. It has the following objectives:

To evaluate the implications of development and use of site specific Habitat Suitability Indices (HSIs), versus the selection and application of generalised HSIs. This will be carried out through the statistical comparison of habitat suitability criteria developed on single river reaches and pooled from different sites, criteria developed at different flows and different times of year. To test that IFIM/PHABSIM predictions of physical habitat are robust and reflect the availability of physical habitat (defined as combinations of depth, velocity and substrate) within a study sector.

Calibrated PHABSIM hydraulic models will be compared with unbiased samples of physical habitat taken within a river sector. To evaluate the relationship between temporal changes in brown trout and salmon population and physical habitat availability at four sites. Calibrated PHABSIM hydraulic models will be compared with long-term fish population records.

The benefit for COST Action: This project forms a major part of the CEH contribution of resources to the EAMG COST Action. Testing and validation of models to predict the impacts of anthropogenic changes on river systems is a key issue across Europe. In order for rivers to be managed successfully at the catchment scale, rigorously tested impact assessment techniques are required which work at the sub-catchment level. EAMG / COST will enable improved model testing procedures to be developed, through sharing of existing methods and data. This will benefit both this project and other similar projects within this action as a whole.

Bioenergetic response to habitat of brown trout and salmon juveniles

The project seeks to develop a conceptual model which incorporates aquatic habitat to predict net energy intake at feeding positions in study sites. The model will be tested against observed data on salmonid fish habitat use in one upland and one lowland river under different habitat conditions: physical habitat (water depth, velocity), water temperature, light level and turbidity and food availability.

The benefit for COST Action: A key feature of this project is that it aims to move towards a more process-based description of fish behaviour, which should be able to underpin a new generation of impact assessment techniques. In the longer term, this could enable river managers to move away from part of the costly empirical data collection exercises inherent in impact assessments today. In addition, such models will have a scope much wider than the assessment of instream flows, and should make a major contribution to the development of freshwater fisheries science. However, in the short term, such models require considerable development, and the data required for their validation is considerable. No one research institute will be able to take such techniques into the next generation, however jointly within the EAMG COST framework, major progress should be possible in the next four years.

Modelling urban river corridors: The scientific basis for urban river management

River corridor ecosystems are largely determined by the interactions between three principal boundary conditions; namely the flow regime, the water quality regime, and the physical habitat. Channel modification and the higher incidence of flooding occasioned by urbanisation are associated with a loss of physical habitat diversity coupled with higher levels of bed shear stress than would prevail naturally. Low flow discharges may also be reduced leading to a loss of aquatic habitat and loss of dilution for pollutant inputs. However, downstream of sewage works, dry weather discharges may be enhanced, often with appreciable diurnal variation. Point and diffuse sources of pollution yield a complex mixture varying in time and space. The speciation and partitioning of the chemical load may vary with pH, degree of oxygenation, and temperature, and thus affect bioavailability. As many pollutants have an affinity for finely divided suspended solids, sediment transport is often a major factor with respect to pollutant fluxes.

This project is addressing this knowledge gap and will accordingly lead to advances in scientific knowledge of urban drainage systems that are important in the context of urban regeneration. It will lead to advances in scientific understanding of urban drainage systems and will result in improvements in the tools available to catchment managers for evaluating a wide range of catchment and river management strategies.

The project addresses key issues in environmental science at the interface of hydrology, geomorphology and ecology. It seeks to examine the dependence of urban river ecosystems upon the boundary conditions of flow, water quality and physical habitat. The precise nature of the dependence upon these boundary conditions is far from clear and may vary throughout the river system, but the contention is that even in highly polluted urban river systems, the flow regime and nature and diversity of physical habitat also significantly influence the river ecosystem. Thus all three boundary conditions and their interactions require investigation.

The benefit for COST Action: The study of the physical habitats of rivers in urban environments has received comparatively little attention. In the past year, this research project has provided us with vastly improved understanding of one river: the Tame in Birmingham. Preliminary results have shown that even in moderately polluted rivers, the nature of the instream physical environment is a major factor determining the distribution and abundance of aquatic macrophytes and invertebrates. Through sharing our experiences with other COST partners, we hope to provide a catalyst for the development of improved techniques for the management of the physical aspects of European urban rivers.

Environmental impacts from hydropeaking

The Norwegian electric energy supply system is based on hydropower. The newly deregulated energy market will probably lead to increased use of hydropeaking. The effects of hydropeaking on the aquatic ecosystem are not well understood. The Norwegian Research Council, several power producers and the authorities have established a research program to focus on the impacts on the ecosystem from hydropeaking.

Stranding of juvenile fish is an important impact from hydropeaking. Experimental studies in peaking rivers shows how juvenile Atlantic salmon and Brown trout respond to rapid flow decrease. Additional experiments are being carried out in a semi-natural river of 5m x 30m in the laboratory.

Short-term temporal variation in both composition and distribution of available physical habitats for juvenile Atlantic salmon have been analysed at study sites downstream peaking hydropower plants. Physical

Fish behaviour and shelter type selection in Brown trout and Atlantic salmon during hydropeaking have been investigated in laboratory by video obeservations and in natural situations using high precision telemetry and snorkeling.

Water vegetation downstream of a peaking hydropower plant has been investigated. Hydraulic conditions for a part of the river reach have been modelled. Time series analysis shows the impact from the hydraulic conditions on the water vegetation.

The impact on fish growth and stress reaction from variable flow conditions will be investigated in laboratory and a semi-natural river.

All the subprojects will be integrated and results will be analysed together, leading to an overall development of new methods and simulation models to assess environmental impacts of hydropeaking.

The benefit for COST Action:: The project will lead to increased understanding of interaction between physical processes such as changes in water flow, velocity, depth and temperature, and the aquatic ecosystem. The project will develop new methods and models to describe these interactions.

Ecologically based minimum flows

In regulated rivers man have the power to manipulate the discharge through the year. The authorities have, up to now, determined by law a strict minimum discharge in regulated rivers. Minimum discharge restrictions have for some regulated rivers in Europe been differentiated between summer and winter. Up to the late 70-ies it was a lack of useful decision support tools to assess the discharge for a multithread activity in rivers. Despite increasing ecological awareness during the last decades, many regulation licences are still based on old regulations, and valid for 30-50 years. However, the IFIM method and other similar habitat assessment tools have made it possible to quantify the best habitat conditions in rivers on a micro scale, and serves as a strong tool in determining an acceptable (stable) minimum discharge.

Knowledge about ecological response of discharge and extensive use of numerical models for simulating the distribution of discharge can be used to introduce new assessment studies. It is necessary to regard the total amount of "minimum water release" throughout a year as an available quantum and then form a discharge curve as a function of time in a way that gives the optimal use of this portion of water. Water discharge controls factors in the river like temperature, chemistry, ice, erosion and hydrophysical parameters and the knowledge of this must be included in the design of the discharge curve. This means that some parts of the season will see a lower discharge rate, while there will be water saved for higher discharge in more critical periods of the seasons. Some attempts towards more flexible regulation regimes are done in regulated rivers. In some Norwegian salmon rivers the power companies are imposed to create attraction floods and to flush out unwanted aquatic plants. Resent studies underline the strict dependence between discharge and biological habitat.

Several available models are suitable and needed for simulations of ecological optimal run of water works. The nMAG model is developed for operational management of power stations, originally to determine the optimal economical gain from a series of reservoir. nMAG is not only useful in hydropower applications, but it can also be used to simulate other water distribution schemes involving reservoirs. A strong point of using nMAG is the link between water releases and economy, which provides us with the ability to calculate the cost of different flow mitigation strategies. The HYDRA model is a flexible modelling system superior for doing ecological sound water work operations. This river modelling system include both reservoir operation strategies, hydrological models on a sub-catchment level and different flow routing procedures for river reaches, which serve as the link of the HABITAT results with macro habitat parameters. Further, SINTEF have started to develop a new model tool for simulating habitat improving efforts in rivers. This model is an integrated system between SSIIM (3-D hydraulic model) and HABITAT on a reach level. By changed geometry of a river reach the model are simulating the following response of the habitat.

SALMOD, developed in Forth Collins by US Geological Survey, is one of few existing models prepared for simulating the production of salmon on a population level as a response of discharge. This model should be adjusted to other conditions and species, and is an exciting tool for doing assessment of discharge response on a population level.

Further, SINTEF have started to develop a new model tool for simulating habitat improving efforts in rivers. This model is an integrated system between SSIIM (3-D hydraulic model) and HABITAT on a reach level. By changed geometry of a river reach the model simulates the following response to the habitat.

The benefit for COST Action: Modelling tools to quantify the seasonal bottlenecks for riverine ecosystems, to simulate the flow-dependent response on invertebrates and fish on both a individual and a community level, to develop an habitat improvement model tool for simulating effects of habitat improving efforts, to define an ecological optimised discharge through the year for a set of regulated rivers of Europe and to develop integrated tools for determining ecological versus economical gains resulted from various discharge regimes will be available.

Riverbed and nearbead hydraulic processes and interactions

The project will basically be conducted as a Ph D study at the Norwegian University of Science and Technology in close collaboration with the project in chapter 6.1. The scope of the study is to increase the scientific knowledge of nearbed and riverbed hydraulic processes and interactions in natural and regulated streams.

The focus will be on hydraulic forces, processes and interactions with the nearbed biotic community, preferable fish juveniles. The study will be designed and performed in close collaboration with the project "Sub-lethal effects on fish of short-term rapid changes in water level/water flow in regulated rivers" and aim to produce significant input to the physical stress factors of the fish juveniles.

Regulation of rivers might lead to substantial changes of the biotic and the physical processes in rivers, depending on how the river regulation is managed. With an increasing power demand and the scenario of increasing export of Norwegian produced hydropower during high demand periods in Europe, there is an need for increased scientific understanding of how the management of regulations affect the biotic and physical processes on a short and long term base. A few themes and possible implications are listed:

	Reduced or no large floods may lead to less diverse river biota
	Hydropeaking may lead to decreased growth and increased mortality for juvenile fish
	Reduced sediment yield, may lead to less fine substrata and loss of physical habitat
	Increased erosion downstream hydropeaking plants, may result in loss of physical habitat
	Reduced erosion and increased sedimentation downstream stable production plants, may lead to increased level of riverbed and flooding catastrophe at extreme floods, may lead to increased mortality of fish eggs
	-increased or reduced surface ice and anchor ice, may lead to loss of physical habitat during winter

The project will include experimental studies on drag forces and abrasion on fish bodies in flumes and natural rivers at different hydraulic regimes: different roughness, steady flow/ rapidly varied flow etc. Hydraulic modeling of position-specific dragforces and abrasion, integration of forces and stress over time and space will also be carried out.

The benefit for COST Action: The project will improve the understanding of links between physical processes in and near the river bed to be implemented in models and methods for assessing the aquatic ecosystem.

Spatial scale and patterns in habitat modelling

During the pilot study in Gjengedalselv the main goal was to predict habitat selection at a river station scale (50 - 200 m). The modelling cells who form the smallest spatial unity, is of several m² in size. Compared with fish sizes on the micro scale of 5 - 25 cm, this is a big scale. The methodology is then based on the assumption that it is possible to extrapolate from the micro scale up to the model scale of several m². This assunption has never been validated. A main goal in this project is to collect data and carry out model simulations on a scale more fitted to the fish sizes. The results from simulations on these two scales will be compared and analysed.

The testing of spatial scale importance requires a lot of resources. Only one of the stations in Gjengedalselv will therefore be chosen for this part of the study.

The testing of the existing quasi-two-dimensional hydraulic model will be run parallell with the application of a new three-dimensional hydraulic model. The three-dimensional modelling technique is expected to be much more suited for habitat modelling than one- and quasi-two-dimensional modelling of averaged values. One of the main objections to habitat modelling for impact assessment studies has been the use of averaged values in the one- and quasi-two-dimensional modelling techniques. A three-dimensional hydraulic model will provide us with detailed descriptions of the physical environment both along and perpendicular to the flow direction. This will be an important step further in solving spatial scale problems in habitat modelling.

There has been collected a great amount of data in the Gjengedalselv. All former model predictions are based upon the same data basis. The predictions can be seen as hypothesis about fish response to changing hydrophysical conditions. Seen from a scientific point of view, all hypothesis should be tested and validated. This testing and validation have so far not been done in Gjengedalselv (or any other places in Norway, and very few places elsewhere). The testing will be performed in two ways: (a) internal testing and (b) external testing.

(a) Existing data will be used for internal testing of model predictions. Based on general preferences from the whole river, the model predicts where preferred, indifferent and avoided habitat will occure. Internal testing can be done by looking at the location of observation and checking them against model predictions. It will also be possible to run an internal test on different scales to investigate the correlation between model preformance and spatial scale.

(b) Using an independent set of data from one station in the river to predict habitat quality for another station will give an external testing of model predictions. The data collected from part 2.1 could be used in this study as long as they are corrected for the proper spatial scale. There will also be collected a new data set of habitat use at all stations. This will be used for a comprehensive external testing.

Up to now only static models have been used for habitat simulations. Changes in flow and water temperature can effect the habitat selection. It is very resource-demanding to run dynamic models on a large spatial scale. However, the importance of dynamics can be tested with detailed studies on a limited small spatial scale.

Water temperature controls some of the habitat selection. The theory is not well quantified and we have not yet implementet the importance of water temperature in the model. Studies on salmon and trout have indicated that water flow also directly controls some of the habitat selection. This theory must be investigated and eventually quantified and included in the model.

The results from dynamic models will also be compared with static modelling results.

The benefit for COST Action: Scaling problems are one of the main challenges in this COST Action. This project will bring research results for upscaling (and downscaling) from a very detailed scale to a mesohabitat scale. Validation of modelling techniques will also be emphasized.

Simulation model development

Simulation models for assessing impacts on aquatic ecosystems are continously being improved and developed for use in several projects. The model development includes hydrological models, hydro operation models and models for physical, chemical and biological processes in rivers and lakes.

The benefit for COST Action: All models will be made available for use in the Action, including semi-commercial models like The River System Simulator.

Importance of habitat structure and discharge fluctuations for the biodiversity and integrity of floodplain fish assemblages.

Floodplains in alpine rivers and floodplains in Swiss low land rivers will be studied. Fish habitat as functions of river discharge are identified and mapped. The temporal use of the habitat will be studied on different time scales (seasonal, weekly and daily time scale). The importance of different habitat structures and types should be recognized for different life stages and different fish species. We will put a clear focus on threatened fish species (nase, grayling, soufie etc.). Habitat suitability-curves for different life stages for some threatened fish species will be established. The dynamic floodplain habitat characteristics will be modeled.

The benefit for COST Action: Habitat model of a very dynamic system.

ÖKOSTROM (ecologically based minimum flow) in collaboration with University of Stuttgart.

In order to determine an ecological based minimum flow regulation intensive habitat studies are carried out in the Brenno River, an alpine river in the southern part of Switzerland. Field studies were carried out in 1999 and will be continued in 2000. There is a main focus on habitat availability, habitat use and preference for brown trout. In addition, grayling or soufie (Leuciscus souffia) will be studied. The habitat conditions (availability/use) and preference will be documented at several sites along the river continuum. With our studies we collect the biological data (habitat use), the habitat simulation tools are developed and provided by the University of Stuttgart (M. Schneider/K. Jorde).

New Fuzzy approaches for fish habitat characteristics will be developed. In addition, habitat models for alpine rivers with a quite high river bed roughness will be available.

The project has to be regarded as a contribution of sustainable use of water for hydropower production.

The benefit for COST Action: Hydropower use of rivers based on ecological criteria is a main aspect in the use of water resources. Substantial contributions are expected for further hydropower use of rivers. Intensive cooperation with the University of Stuttgart.

Hydropeaking

In hydropower production, hydropeaking has to be regarded as one of the serious problem for the ecology of streams and rivers. In addition to the ÖKOSTROM project we intend to study hydropeaking problems in alpine Swiss rivers. The financing is not yet secured, but in order to mitigate adverse effects from hydropeaking different studies should be carried out. Mainly the diel habitat change and behavior of fish during seasons will be important for the study. In order to locate exact habitat positions of fish during hydropeaking radio telemetry will be used. For this project cooperation with international partners is planed.

The benefit for COST Action: Several other European countries have similar challenges in investigating environmental impacts from hydropeaking, thus collaboration in a quite new field will bring European added value.

Stream restoration/rehabilitation projects in Switzerland

In Switzerland in the year 2000 river restoration/rehabilitation projects will be started in cooperation with the local administrations (cantons). Restoration projects have to be regarded as long-term processes to reestablish the predisturbance structures, integrity and functions of rivers. Restoration does not imply that a river must be returned to its pristine condition, but it does imply maintenance of key elements and key processes.

First preliminary studies will be carried out, followed by main studies in 2001-2002. Habitat modeling will be used as a predictive tool to restore/rehabilitate fish habitat and fish communities. Further analyses include evaluation of habitat improvement using habitat models. Post project appraisal are very important and will be carried out for large rivers (Rhone River), smaller rivers and streams. International cooperation with different partners is planed.

Habitat modeling will be carried out for managed fish populations (brown trout, grayling) but also for small sized fish species that are not stocked.

We will put a clear focus on analyzing natural and near natural river sections. These sections will be regarded as reference sites. Comparisons between these sections and between degraded and restored/rehabilitated sites will be made. Therefore a good basis for ecological deficiency analyses will be available.

The benefit for COST Action:: In Europe there is a substantial need for the control of restored/rehabilitated river sections. Evaluating restoration success by habitat models is essential and helps to improve subsequent restoration.