Long term observations of Upper Vistula tributaries, made by authors, showed that the narrowing and straightening of the rivers and their floodplains resulted in accelerated riverbed erosion and the increase of flood risks. River floodplains are widely acknowledged as being very important for biodiversity, therefore by their narrowing the floodplains lost their natural patterns with a consequence decline in habitat and species diversity. In the last years appeared a new approach in river management and engineering, the EU Water Frame Directive consists an important step for more ecological river training. In consequence an increasing number of restoration projects have been initiated in the last years. In the present paper the authors tried to check the possibilities of flood plain widening upstream of the Nowy Sącz City situated on Dunajec River (km: 111+900 - 107+500), where are devastated wastelands. In the urban area of Nowy Sącz the levees distance was left unchanged. For the new conditions the numerical simulation by 1D mathematical model RubarBE was carried on. The obtained results showed the significant decrease in the flood peaks upstream of Nowy Sącz and some in the town. ...
The aim of the paper is to present the studies on the riverbed erosion on the upper course of Raba river, located from km 81.829 to km 77.751, close to the Stróża gauging station located in km 80.600. This part of the river course is com-pletely changed due to the Project concerning the extension of the Zakopianka road located close to the Raba river. The results of simulation of riverbed evolution before and after the Project carried out by two 1D models (RubarBE and Metoda) are analysed and discussed. The results of computation obtained by both models are verified by field observations carried out in 2001 (before the Project), and in 2009 year (after the Project). The trends of erosion and deposition correspond to the field observations for the dates before and after the Project. Another verification is possible to make for the Stróża cross-section, where observations of cross-sectional geometry and water stages have been carried out from 1900 year till now. The statistical model of riverbed erosion developed for Stróża also confirm the trends obtained there by 1D models.
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The analysis of time variability of riverbed elevation recorded at four cross-sections of two rivers: Raba and Dunajec was made. The causes of very intense erosion were pointed out, namely: intensive sediment extraction, inadequately carried out river training works including shortcuts and narrowings of riverbeds, and constructions of hydro-technical facilities, disrupting the continuity of sediment transport along the river length. Forecasting was carried out using a local weighted regression method, LOESS. In order to examine how far the length of the historical series influences the quality of forecasts, a comparison was made between the 5-year forecasts based on the 5-year history and the 5-year forecasts based on the 10-year history. The results suggest the need for preliminary data analysis before using a particular version of the model in or-der to take into account the type of variation exhibited by the historical series. ...
The long-term evolution of the river beds of Nida River in Pińczów and Wiślica gauging station as well as an analysis of the causes of significant cases of lowering of the bottom of stream beds are presented in the paper. The intensity of river bed evolution as a stochastic process is described with the use of a statistical model. The analysis of the intensity of the process of river bed erosion was con-ducted under the assumption that the observed long-term trend of the lowest annual water levels reflect the elevation of the river bottom in the same years. The recorded observations at the Pińczów and Wiślica gauging stations on the Nida River, covering over 70-year period of time, are analyzed. Observations of the variability in the studied bottom levels over the decades allow concluding that the great transformation of riverbeds occurred there. The observations and calculations show that in Pińczów multi-stream or meandering river bed changed into straight channel and the process of shallowing of the river bed appeared. At the Wiślica gauging station the process of riverbed erosion with the variable intensity was observed. The research shows that the causes of these changes observed in Pińczów and Wiślica are ...
Long-term observations of Upper Vistula tributaries, made by the author, showed that the narrowing and straightening of rivers and their floodplains resulted in accelerated riverbed erosion and the increase of flood risks. River floodplains are widely acknowledged as being very important for biodiversity, therefore by their narrowing they lose their natural patterns and, as a consequence, decline in habitat and species diversity. In the last years a new approach in river management and engineering appeared: the EU Water Framework Directive constitutes an important step for more ecological river training. In consequence an increasing number of restoration projects have been initiated in the last years. In the present paper the author tried to study and check the possibilities of flood plain widening upstream of the town of Nowy Sącz situated along the Duna-jec River (km: 111.900 - 107.500), where devastated lands occurred. In the urban area of Nowy Sącz the levees distance was left unchanged. For the new conditions the numerical simulation by 1D mathematical model Rubarbe was carried out. The obtained results showed a significant decrease in the flood peaks upstream of Nowy Sącz and lesser decrease in the town. ...
The article presents an assessment of the variability of riverbed sediment throughout the Przemsza river course and its main tributaries in relation with the observed disturbances of grain size changes caused by hydro-engineering activity in the channel. Sediment grain size composition in the river channel depends on the hydrodynamic balance and the water flow. In the stable river channel sediment grain size decreases regularly with the river course from the source to the mouth. In the channel where there are sections of anthropogenically modifications, the variation of sediment grain size composition may be irregular in the river course. The article presents the results of measurements and calculations which were made in the following gauging stations: Łysa Góra, Będzin, Sosnowiec, Jęzor, Chełmek non Przemsza river, in Golczowice, Okradzionów, Sławków, Maczki, Niwka on Biała Przemsza river and in Brynica, Kozłowa Góra (above the back of the reservoir Kozłowa Góra and downstream the dam), Szambelnia on Brynica river. The results of studies showes that variability of characteristic diameter of d10 is minimal, while the diameters of d50 and d90 is characterized by significant differences in all the tested gauging stations of Przemsza river and its tributaries. In Brynica river where ...
The analysis of variability of riverbed elevation recorded at three selected gauging cross-sections: Raków, Staszów and Połaniec on Czarna River is presented in the current paper. The studies concern the period of more than fifty year. Focus was on the analysis of the riverbed changes in relation with known anthropogenic activities in the bed of the river. In addition, an analysis of grine size distribution of sediment forming the river channel was examined. The studie was done in order to identify the structure of riverbed, as well as the intensity of sediment movement throughout the ricer course. Czarna river is a left tributary of the Vistula river, at a considerable length, is transformed as a result of technical river channel regultion. At 36+000 km of the river course, Chańcza dam was set. The mouth of Czarna river is located close to the Town of Połaniec. The river channel aspire to shape a new longitudinal profile of hydrodynamic balance in new conditions of fluvial system, by changing its shape in the vertical and horizontal direction. As indicated by river channel observations, changes are very fast after a disturbance, after which they are weakening, and the riverbed reaches again hydrodynamic equilibrium (eg. ...
The analysis of variability of riverbed elevation recorded at three selected gauging cross-sections: Stróża on Raba River and Żywiec and Oświęcin on Soła River is presented in the current paper. The studies concern the period of more than one hundred year. Focus was on the analysis of the river course maintenance in selected gauging stations. Research shows that the river course may change spacially and temporally with varying inensity. In the period of 50 - 100 years, these changes can be slight, but it can be also observed permanent change in the direction of the river channel development. The paper presents the trends of riverbed changes during the long period of time in selected mountain tributaries of the upper Vistula River, which were studied on the basis on the variability of observed mean annual water stages. In the paper there are given the reasons for the observed changes in the river course and channel geometry, which were caused by river regulation relayed on the shortening and narrowing of the river channel or the sediment exploitation. Presented in the article method of assessment of the variability of the river channels level in the long period of time may be the ...
On Trzebuńka stream, in Stróża village, the project of lowering of 4.0 m and restoring the check dam has been executed. The structure downstream was redesigned to form rapids, made of stones embedded in the "grouted rock" construction. Now, the whole construction of 12 small water reservoirs forms a kind of long fish pass. The preliminary results of stream channel evolution on Trzebuńka stream above the restored check dam are presented in the paper. There are described the local cases of check dam liquidation or restoration in the World. However, there are still many questions concerning the response of stream channel to such technical intervention. The problem of rate of sediment displacement in the reservoir and the consequent erosion base reduction for the channel above is discussed. The field measurements and observation show that two years after check dam lowering and emptying the sediment reservoir on Trzebuńka stream the transformation of new formed channel upstream the new structure is dynamic. At the length of 180.0 m upstream the new dam the bank erosion is significant. Just above 200.0 m upstream from the structure the channel is stable. ...
A check dam is a hydraulic structure, which is constructed in order to limit river sediment transport. A sedimentation reservoir is created upstream from the body of the dam, where river sediment is constantlyaccumulated. These structures were constructed starting in the early 20th century in upstream parts of mountain streams in the Polish part of the Carpathian Mountains. At present, the reservoirs of most check dams are already fully filled with sediment and the impact of these structures on the ecosystems of streams is unfavorable. Moreover, the dams that have not been renovated are in poor technical condition. In the paper two cases of check dam lowering and restored is discussed and the one hypothetical case of gradual check dam lowering is presented and discussed as well. The cases of Krzczonówka and Trzebuńka, where the method ofremoving sediment from reservoirs was different, showed that the sudden change of „established" hydrodynamic conditions for decades is not favorable for the stream. The results of hypothetic simulation of gradual check dam lowering for the case of Isepnica Stream leads to the conclusion that lowering the construction of check dam and removing sediment from its reservoir in a way that does not have a ...
The last years' floods, in particular in the Upper Vistula Catchment, caused serious damages by inundations by small torrents and mountainous rivers. It was proved that hydraulic works and land-use changes usually induce an acceleration of runoff throughout the catchment, which can locally enhance erosion, damage river ecosystems and worsen floods. The "Dynamic Slow Down" concept therefore promotes slowing down, using transverse obstacles or small retention works. In accordance with sustainable development, DSD claims that hydraulic projects must be planned at catchment-scale and must take all the stakes into account, including ecological issues. Cemagref and Cracow Institute of Water Engineering worked on from 1999 a DSD feasibility study in the Polish Isepnica catchment. In the present paper we continue the work including the simulation of the change of three sediment check in dams dry reservoirs. To deal with flood and erosion problems, they proposed small works in hillslopes and a dry reservoirs.In the paper the DSD methods were applied to Isepnica Torrent (Soła River Tributary). Implementation consists on simultaneous management of the hillslopes and the river bed in order to slow down the runoff, to store temporally water in small reservoirs and in the areas of small ...
The high precipitations, which appears now very frequently, are the main causes of damages in the infrastructure and the properties. Protection against flood should be still developed, but with the special attention on ecology and keep-ing the continuity of water and sediment flow throughout the river channel. Dry dam structure is efficient to mitigate floods, while little disruption of the continuity of the main channel and its flows outside the flood periods. In the paper we ana-lyse the efficiency of selected dry dams during the flood events. We have studied the dry dams located in southern France. In few cases the studies have shown, that dry dams had to be reconstructed in order to protect the area against the flood. ...
In order to protect the areas against the floods and droughts effect, we need to slow down the outflow in the scale of the whole catchment. The streams and rivers training are one of many possibilities of floods and droughts mitiga-tion. However, these activities often were done without any respect on the basic principle on keeping the ecological continuity of river corridor. In the paper, we propose improving the activities in the rivers and streams channels, in order to al-leviate effects of the technical training. ...
Dependly on the the land-use management, there are different technics of river training. The main aim of river training is floods mitigation. However, these activities often were done without any respect on the basic principle on keeping the ecological continuity of river corridor. In the current paper we present four types of trained river cross-sections, depend on their shapes, the material which forms them, and the condition for fauna and flora. There are also performed the patterns of the regulated channels, which are located in the different kind of urban area. For the selected trained river courses, which are located in the Upper Wisła catchment, the possibility of restoration has been analyzed.
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The one of the Polish rivers richest in water with substantial flood hazard and important hydro-energy potential. Two large flood protection and hydroenergy schemes were constructed on the Upper Dunajec: Rożnów-Czchów and Czorsztyn-Sromowce Wyżne. Lower Dunajec extends downstream from the Czchów hydraulic barrage to the outflow to the Vistula and is 67.4 km long. Construction of two large hydraulic schemes resulted in the increase of the low and average discharges, however, simultaneously important disturbance of sediment transport occurred. A large amount of sediment is deposited in the reservoirs. As the result of this process, significant erosion was observed along the Lower Dunajec reaching in some places even 4 m. This process was increased by the sediment exploitation from the river channel. Due to flood problems several training works were executed along the Lower Dunajec. All these resulted in lowering of the river channel, which became a draining river. Stabilization of the river channel is possible by means of the construction of special weirs with inflatable gates. Construction of the weirs gives the possibility of using heads for hydro-energy. It is proposed to construct small hydraulic power plants, which would operate during low and average discharges. ...
