Zeszyt: 2006, vol. 3 / 4 / 1
A modern approach to the problem of flood protection resulting from the necessity of integrating the three objectives of water management: conservation of water resources, meeting necessary water demands and protection against flood and other natural hazards is presented in the paper. In its flood-protection aspect, the approach forces fulfilling environmental criteria when protection measures are being selected and implemented. Also, the approach requires that the flood prevention which helps in restoration or conservation of natural condition of runoff from the catchment be treated on equal terms. This clearly has a positive effect on the correct linkage between flood protection and the natural values of rivers and their valleys. In this way, when solving a social-economic problem, which is flood hazard reduction, we preserve or protect against degradation the good ecological status of running water resources and therefore also the state of the related terrestrial and aquatic ecosystems. This creates favourable conditions for protection of natural values that are an integral part of these ecosystems. The assumptions and principles that water manager and hydro-engineer should follow when seek solutions to flood hazard reduction are the subject of the paper. However, the paper does not contain particular references neither to the ...
The aim of river and valley restoration is re-establishment of natural or close to natural state in which the river channel and valley were before regulation works. River and valley were losing their natural state due to various factors. Mostly, it was connected with the radical changes as the result of the regulation works, i.e. river bed straightening , river gradient increase, standardization of size and shape of river cross section , liquidation of banks and channel bed irregularities, ecotones destruction, cutting off links between old river-bed and main river channel, reduktion in overbank flooding and floodplain storage. Increasing of water pollution in the past it was also chemical factor which changed natural state of rivers. Restoration is usually long-lived process which consists of different technical measures and induced by them ecological changes of water body and surroundings areas accomplished by nature. The full re-establishment of natural state is not possible in practice. By the time the restoration works begin the hydrological, hydraulic and environmental conditions should be recognized. The restoration works may be placed in the river bed, bank zone, along river valley and in tributaries or in the catchment area. The process of restoration encounters many and varied ...
The diversity of habitats and species in rivers valleys of Poland has European significance. The occurence of habitats and species, in certain proportions and quality, is a basis for including area of their occurence into the Natura 2000 system. Ca 40% of areas of Natura 2000 include river valleys and they comprise both areas important for birds (Birds Directive) and for habitats (Habitat Directive). Directives of EU do not impose methods of habitat and species conservation. The only criterion is maintenance favorable conservation status for them. That means that the area of habiat must be stable in the long term or increasing, and its quality must being maintained. The restoration processes are welcomed. The plans for all investments or any other works which might influence the favorable conservation status of habitat and species must be subjected to environmental assessments, which recognize influence of project on habitats and species protected by directives. In the absence of alternative solutions only overriding public interest may allow for habitat or species deterioration; for some species or habitat only human health or public safety are more important. In such cases compensatory measures has to be employed to maintain Natura 2000 is previous status. Specific management ...
In comparison with previous achievements connected with implementation of the European Union legislation related to the water resources management, the potential critical points of the Water Framework Directive implementation in Europe and in Poland are presented. In assessment of potential risk, organization of the implementation process, its financing and schedule, as well as data issues were considered. The demanding schedule of the Directive implementation is based on six-year cycle of planning, with established logical sequence of particular actions. Realization of each action on time, let us to go to the next point of the schedule. In order to implementation European regulations coordination of work and cooperation among all institutions involved in the whole process is necessary. Only mobilization and integration of circles connected with water resources management, allow to work out the best solutions, which allow to fully implement of the WFD resolutions. From among already finished work related to the Directive, in this paper Authors focused on experience connected with realization: “Assessment of the hazard that aggregated water bodies will fail to meet the environmental quality objectives” and “Assessment of the risk that aggregated water bodies will fail to meet the environmental quality objectives” in pilot catchment area of ...
In this paper author presents scopes and rules of agri-environmental programme in Poland including all packages and their options connected with a different implementation area, payments calculation and the first results in Poland and especially in Malopolska province. The following packages have been described in details: sustainable farming (codes: S01), organic farming (S02), maintenance of extension meadows (P01), maintenance of extensive pastures (P02), water and soil protection (K01), buffer zones (K02) and protection of local breeds of farm animals (G01). Each package covers a set of several strictly defined requirements, going beyond the Usual Good Farming Practices, which also have been presented in the paper, and does not overlap with other CAP support measures. ...
In this paper the two-dimensional depth-averaged momentum and continuity equations for steady shallow flow and sediment transport are described. This two-dimensional model is used to study of the bed deformation in alluvial channels. The perturbation of mean values in the cross-section of hydraulic flow parameters is determined by the periodic function which describes the non-uniform but steady flow. The function of this type allows the investigation of the flow stability in both: the straight and the curvilinear cannels. For these channels bed topography and horizontal distribution of depth-averaged velocity in longitudinal direction can be computed from exponential-periodic solution of the momentum and continuity equations. Bed topography computed from this solution is compared with bed topography of two bends in the Warta River. It was found that this solution is in good agreement with the measured bed topography in the river. It is also found that the cosine-generated curve is the natural curvature of the river meanders. Two equations for the calculation of the minimum value of meander curvature at the apex and the optimal length of bend are also presented in the paper. ...
The paper presents an approach to the understanding of the structure and dynamics of mountain rivers which is primarily based on field research. Applicable methodologies have been developed at the Department of Geomorphology of the Jagiellonian University, Cracow. In studies of entire channel systems individual channels are divided into uniform reaches on the basis of their pattern as viewed on a map, and then investigated in the field with the use of specially designed survey forms. The forms cover five groups of data which are the identity of the channels, channel landforms, deposits, civil engineering structures and the characteristics of the drainage basins. The data collected provide insights into the rates of morphogenetic processes. Cartographic material, aerial photos and other information on the channels and their drainage basins should also be analysed in parallel with the field research. The channel parameters, landforms and bedload information, as well as calculated indicators on the channel reaches, provide the basis for a typology of channel reaches. A number of cases from selected research studies are discussed here. General patterns in the development of mountain river channels are also presented which are derived from studies of Carpathian and foreland rivers. These studies concluded that ...
The formation of an armouring layer can be observed on the base of morphological changs by direct measurements of granulometry (grain diameter generally grows after flood) or by computer simulation of changes of the grain sieve curve. This procedure is based on the Gessler’s analysis of the probability of grain movement, on the basis of the shear stress of the acting water. The critical shear stress is calculated using the Wang function developed for Carpathian streams. The armouring layer is formed by that part of non-cohesive bed material, which is not washed away during the flow. The increase in critical shear stress is due to the increase of the mean diameter dm as small fractions are washed out from the bed. The thickness of the armouring layer is approximately equal to the size of the largest stones of the layer. This process in rivers with natural flow is different from this one below reservoirs; in the former case it takes place at a significant distance below dams. In this case, the armouring layer formation causes bed scouring, linked with a change in the water slope and depth. This scouring may be assumed to be a stochastic process. According to Gessler, ...
The paper is the overview to the methods of river valleys’ hydro-morphological (eco-morphological) evaluation, which have been used in Poland and other countries since 1980-ies. Author takes up the problem of evaluation accuracy and subjectivity in particular methods and the role of “biological” parameters in different valley zones. The usefulness of vast-area surveys and detailed studies are being analysed in the relation to the Water Framework Directive and sustainable development demands. The controversies about the key and particularly valuable species in river valley ecosystems are also discussed. ...
The subject of this paper is presenting actual of works involving the determination of reference conditions for defined categories and types surface waters according to II Annex of Water Framework Directive 2000/60/WE of the European Parliament and the Council of the European Union. The Framework Water Directive [WFD, 2000] makes the framework for the EU activities in terms of water policy, and the introduces in the member states the duty to plan and control water management within river basins. The main objective of the Water Framework Directive is to achieve good ecological status (till 2015) in all the defined water categories (rivers, lakes, transition water, coastal water and underground water). In the following years a good state of waters should be achieved in the areas where present natural, technical and economic conditions make it impossible to achieve in the first stage. In a planistic work over a sustainable development of river valleys and catchments one of the biggest tasks is ecological valuation. In solving this task a very efficient and practical tool includes REFERENCE CONDITIONS made according to Framework Water Directive. Reference conditions make a reference point according to which “the health” of an ecosystem of a given type of ...
The River Vistula features various stages in the development of training measures that started in the 19th c. and aimed to convert it into a waterway. This study focuses on a foreland stretch between the towns of Skoczów and Puławy where the channel, originally meandering, sinuous or braided, has been shortened, narrowed and deepened as a result of engineering projects (Fig. 1, Fig. 2). Big differences were identified in the reshaping of the channel studied following the training measures, resulting in a reduced flood risk along those reaches where the channel depth was increased the most and in a considerable increase of this risk below Zawichost, where the measures were carried out last. The one morphological effect of the engineering that has the greatest impact on the discharge regimen is the increased channel compactness, especially along the originally meandering reaches (Fig. 3). The bank height along the deepened channel reaches increased by 3.5 metres on average since the project started. The changes in the channel morphology are conducive to faster flow rates (Tab. 1), which means that the bankfull discharge increases fast along the considerably deepened channel reaches with built-up banks. This rate is much slower along reaches with less ...
The paper summarises research into the geomorphological and hydrological effects of river training and improvement measures taken 45 years ago in the Nida valley. Positive and negative effects were identified, the latter including an increased flood exposure in half of the study area. The study aimed to find a feasible solution that would mitigate the flood risk. The valley is protected as a landscape park and belongs to a network of environmental corridors of national importance. Prior to the training measures, the River Nida, down from the confluence of the Czarna Nida and Biała Nida, ran in an entirely meandering channel with a minimal gradient causing long-term stagnation of the floodwater in the floodplain. The training and melioration measures were aimed at mitigating the flood risk, accelerating flood water drainage and draining part of the valley that had been used solely as meadows and pastures (Fig. 1). Vast wet marsh areas prone to cyclical channel avulsion were predominant along the braided reaches, such as near Umianowice (Fig. 2). As the engineering project started in the upper river course and continued downstream, the channel reaches directly below the newly deepened reaches became shallower. The process was documented by records of minimum ...
The Nida River flows trough the southern part of Poland. The basin of this river is localized mainly in Swietokrzyskie province. It is a longest river in this province (151.2 km) flowing in it's upper part trough the southern part of the Swietokrzyskie Mountains. In most part Nida is a not regulated lowland river, characterized by the slope of about 0.65 promiles. The Nida River valley between cross-sections Stara Wies and Pinczow had been strongly transtormed. Between villages Stara Wies and Motkowice, the typical river training had been done. The river also was partially trainned on the distance between Motkowice and Pińczów as well as in the short distance below Pinczow. The Nida River embankments are localized in the middle part so a big part of the river valley cannot be used as a small retenition. These narrowly distributed fortiffications are in a weak condition, what causes that spring flood waves which often reach the top of the embankments can easily destroy the embankments and flush onto the valley some of their parts together with the sandy substratum from below. The water flowing trough the destroyed part of the embankment transports the high volume of sand from the riverbed which, ...
The aim of the paper is to predict a morphological changes of the riverbed on a section of the Skawa River within back-water reach of Świnna Poręba water reservoir. The increasing bed level which is a result of deposition of bed material, have influence on water surface elevation during flood and can threaten surrounding areas. Between spring 2003 and summer 2006 carried out measurements which consist of: survey measurements of a section of Skawa River, granulometric composition of the bed material, velocity profiles and measurements of the water surface elevation during flood events. Prediction of the morphological changes was possible using twodimension CCHE2D model developed by the University of Mississippi. The numerical modeling focused on the simulation of historical flood events, t-year discharges with probability between p=50% and 0.1% under different water levels in the reservoir ranged between 304.56 m a.s.l - without back-water effect and 309.60 m a.s.l. - normal water surface level. The simulation runs included bedload and suspended load transport which caused of bed elevation changes. Back-water reach, where deposition take place, depends on reservoir water surface level can extend up to a distance about 1.5 km. Numerical results of forecasting of fluvial processes on the studied ...
