Zeszyt: 2006, vol. 3 / 4 / 2
The area of Q10% flood in the over-flood terrace is characterized by irregularity in longitudinal valley profile. The areas of flat, bright flood terrace with small slope in cross-section appears rarely. This kind of stream will run often under deep erosion conditions and the terrace of small dimensions appears on one or both riversides depending on hypsometry and the stream situation. In these conditions the plants cover low water banks and the bushes are dominating the floods plain. This influence during the flood event causes the impact of plants on the flow. The direct effects are: the narrowing downstream and concentrating main flow area in the central part of the low water stage cross-section, changes in velocity profile on the flood terrace with plants as in the transitional plants adjacent area and in the central part of the stream bed. The plants on flood plain are contributing to increase the velocity also in the bottom zone of main channel. The subject of this paper is the analysis of water flow process inside of plants occupying the zone on flood terrace and its indirect influence on hydrodynamic stability of the main part of channel. Due to the influence of plants during ...
The research presents the attempt of natural and production valorization of melioration object Ochoża. It is aimed to evaluate the anthropogenic transformation effects and current swamp habitat. At current valorization, these habitats were considered as corrected taking into account the soil process, soil formation and humidity level. There are soil types: peat-mursh, mineral-mursh, gley and chernozems. Potential valorization results were based on an idea of prognostic humidity-soil complexes. Phytosociological records serving for natural valorization were made within valley bottom. Evaluation of habitat’s current agricultural value for peat-mursh soil corresponds to III bonitation class. There are soil-ecological units classified to V bonitation class with very low efficiency and performance value of the sward on the other part of the object. Area of river Ochoża is of moderate natural value, which results from the simplification and generalization of valorization procedure as well as management of part of valley bottom and long-term soil drying. ...
This article present:- Needs of works management connected with conservation of surface waterand water facilities at restoration areas.- Threats connected with lack of this kind of work.- Type of work connected with conservation and methods oh their management.- Requirements connected with conservation of work at restoration areas. ...
The paper presents the analysis of hydrological drought of the Biebrza river to the Burzyn gauge and Narewka river to Narewka gauge in multiyear 1951–2002. Hydrological drought is usually expressions of deficiencies is surface water supplies. This phenomena is the last stage the drought process and is identify with low flows in river bed. The examined catchment area is part of the Podlaska Lowland where droughts occurred most often in Poland. The research described in this paper was concentrated on the Biebrza valley, which is a unique wetlands area in Central Europe and on the Narewka valley within the Bialowieza Forest, the latter being a natural heritage in the global scale. The Biebrza Wetlands and Bialowieza Forest hydrogenic sites conditions depends on ground and surface water levels and thus, a hydrological droughts is a danger to them. The methodology used in this paper describes the hydrological drought as the situation, where river discharges are below some arbitrarily chosen threshold level. The size of the threshold discharge was established in dependence on aim of study. Truncation level value of drought was applied as statistical value Q90% determined from flow duration curve with the upper discharges. This paper include the proposition the ...
Tywa river valley, located in western part of Szczecińska Plain, flows through moraine areas of Myśiborskie Lakeland and Wełtyń Plain. River valley has high slope values and denivelations, so many hydrotechnical objects were located here in the past. There were no intensive other river regulations and melioration, so valley has still high biocenotical value. Analysis of landuse changes in riverine valley are presented in this paper, as well as analysis of changes directions and patch statistics. Archival topographical maps from 19th and 20th c. were used for preparation of landuse digital maps. ...
Bukowe Hills region, located in Nizina Szczecińska Plan is characterised by complicated hypsometric and geological composition. Heights reach 80-140 m, with denivelations often more than 60m. Complex of small nearly mountain catchments, with maximum area of 5 km2 drains researched region. Characteristic horizontal sections of longitudinal profiles are interesting feature of selected hydrological systems, originated from short period stages of deglaciation. Topographical characteristics of selected catchments were derived from DEM, prepared on basis of topographical maps. Longitudinal profiles of streams and slope maps were analyzed also. ...
In Kamienna River Valley the iron ore exploitation was done for a very long time. The intensification of the mining took place in XVIII and XIX century. For this region played an important role Stanisław Staszic. Kamienna River was supposed to be the source of energy and way of transport. Therefore, the river canalization and intensive training was undertaken, in consequence the river course was straighten and shorten, which resulted in the significant change in the river dynamics. Meander elimination and introduction of a uniform cross-section resulted in deterioration of habitat. To-day Kamienna River has deeply incised bed, which causes the drainage of surrounding grounds. After the analysis of the old maps and the river cross-sections it was found that it is impossible to restore the old river bed, because of the important erosion and cut off the sediment transport by dams on Świślina and Kamienna Rivers. Moreover the canalized river along some industrial vestiges is a part of technical patrimony. Therefore the only slight improvements could be proposed – introduction of slight meanders, more natural bed form and irregular banks. That could be obtained by an introduction of small hydraulic structures diverting the water stream. ...
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 scientific research of the oxbow lake of Słupia River was carried out from 1998 as a preparation for drilling the conception of renaturyzation of Słupia River. It consisted in including particular oxbow lake in the right stream. The research included the analysis of the most important ecological formations with special regard to periphyton living in artificial and biotic substratum. In 2003 Koński Staw, one of the oxbow lake in the lagoon polder of the city of Słupsk, was submitted to the process of dredged. Drainage works created new life conditions for hybrobionts. During the research period (2004–2005) the density of bottom microfauna was increasing noticeably. The density of zooperiphyton living in artificial substratum was also increasing from 132 to 303 thou. indiv. m-2. However, high fluctuation on the biotic substratum could be observed. The density of zooplankton was fluctuating between 9.3 – 15.8 thou. indiv. per dm-3. The results of the research allow to state that the drainage works carried out in the oxbows lake of Słupia River are very profitable for zoocoenoses hybrobints. The removal of bottom sediments with hydrogen sulphide accumulated in reservoirs caused the reconstruction of qualitatively- quantitative structure of macrozoobenthos, zooperiphyton and zooplankton. It allowed ...
The Upper Odra valley on sector between Chałupki (km 20,0) and Olza mouth (km 28,0) is subject of deformations caused by natural factors and by human activity. This sector constitutes the border river between Poland and Czech Republic. Seven unique meanders exist here. The I-st and the IV-th meander have been broken during the floods in 1997 and 1967. Together with road bridge (km 20,530) they constitute three critical places with regard to flow capacity of Odra valley in its upper course. The problem of the border between both states Poland and Chech Republic on this sector is still not solved, what causes serious lawful and economic complications. The studied sector is distinguished by intensive bank erosion and sedimentation. The dynamic of Odra morphological processes is high here, so changes of water course as well as shape of the riverbed are very indicative. At present, the new channels formed within the meanders I i IV are characterized by the rapid flow caused by the high bed slope. From the authors’ studies it follows, that the old river branches permit to pass only a small percentage of the average discharge. Great outwashes, islands and dense vegetation within the meanders cause a ...
The main aim of the article is to show (present) the influence of vegetation zone on concentration of suspended load. New standards (principles, rules) of river engineering conducted in harmony with nature assign enormous plant significance. It is treated not only as a natural factor but also as a component of hydraulic reaction which clearly shapes hydraulic and hydrologic conditions. Until recently it was generally believed that vegetation is only the faktor which makes exploatation of water facilities difficult and unfavourably influence on structure working. At present vegetation has begun to be appreciated as a new element in contemporaly water management which may favourably influence on hydraulic conditions. Vegetation may cause riverbed roughness changes, bed configuration changes, water level slope changes increase of riverbed erosion resistance and also may cause retention of considerable amount of suspended load transported by (in) the river. Existing of vegetation zone in rivers and reservoirs influences on fluvial processes. Vegetation degree and its vertical and horisontal dimension influence on longitudinal and transverse transport of suspended load as well as its variation dynamics. The research of the suspended load transoport in vegetation zone was conducted in Institute of Environmental Engineering on model in scale 1:1. The ...
In the paper is presented the procedure of calculation of the water flow parameters and bedload transport in the small lowland river-bed with a sandy bottom, in which the bank slopes will change roughness by restoration process. In calculation the results of field investigation of flow resistances and bedload transport were used, which were carried out in the natural Zagożdżonka River, located in research catchment of Dept. Hydraulic Engineering and Environment Recultivation Warsaw Agricultural University. The river-bed on investigated reach have following parameters: width of bed at bankfull level – 3 ÷ 4m, bottom width – 2 ÷ 3m, maximal depth – 0.6 ÷ 0.7m, longitudinal slope – about 1‰, bed material – sand with medium size d50 = 0.41mm. Based on results of field investigations the bedload function was established, in which bedload specific rate qr depends on average flow velocity V in river cross-section. The comparison’s calculation of bedload transport show good agreement of results obtained from Bagnold’s and own bedload functions. For prognostic calculations of bedload transport in regulated river-bed both functions were used. In calculation assumption was made that flow conditions in natural Zagożdżonka River can characterize final state of regulated river-bed after restoration process. It ...
It is known that carp ponds significantly affect the quality of surface waters, probably not polluting a water-course during regular production period but only during period of catches or during lowering of ponds. A study on physical and chemical properties of water in one of the Western Pomeranian rivers, the Krąpiel, was undertaken to verify this opinion. More than 200 ha complex of ponds is located in the catchment area of that river, in the settlement of Dzwonowo. The research was done monthly from April 2005 till April 2006. It was shown that lowering of the ponds causes the increase of nutrients, organic matter, and total suspended matter, but also negatively affects water quality. Pollutants however do not influence the increase of eutrophication processes and the river still retains self-purification ability. ...
Groins are structures often used in lowland river regulation. The main goal of their construction is protection of coast and narrowing of the river channel to increase water depth and prolongation of the navigation period. Analysing the influence of groins on hydrodynamics and sediment transport in rivers it is necessary to consider two cases: (1) non-submerged groins, when the groins top is above the water surface, and (2) submerged groins. In case of nonsubmerged groins the narrowing of the main channel is observed; it is accompanied by increase of water velocity leading to further deepening of the main channel. In the groin fields water flows much slower, supporting sediment deposition. In case of submerged groins water flows in the whole channel, but increase of resistance due to groins causes reduction of its capacity, being an important aspect in flooding periods. Water flow is always accompanied by sediment transport, but the existing knowledge in this respect is still insufficient to allow prediction of morphological changes with high accuracy. Groins are constructed since few centuries but not always the expected results are reached; it is not unique that they create new problems (deepening, sediment deposition). Recently laboratory experiments are carried out to ...
In natural rivers, bed forms built of sandy and gravel-sandy fractions may be formed on the river bed at some determined hydraulic conditions. Depending on the type of the flow they can be two- or three-dimensional forms (2D, 3D) and they can have straight or curved crestlines (dunes: barkanous, sinusous, lunate, linguoid or catenary). Any bed form can exist individually (for example isolated dunes), but mostly they occur as accumulated single forms. These forms are placed parallel or transverse to the flow. Moreover, they can be arrangement across the flow. The subject the bed forms arising was involving and still is many scientists from abroad and from Poland and the main topic of investigations. Most of the paper covers the issue of sandy bed forms (in the form of ripples and dunes) which one shaping bottom of the lowland rivers [Młynarczyk (1998), Dąbkowski (1989)] and bed forms which observed on the submarine bottom [Pruszak 1998]. So far, there have been only a few publication in the world concerning existing sandy-gravel and typical gravel dunes [Carling at al. 2000, 2005]. This paper presents results of the hydraulic parameters calculations above gravel curved crestline dunes along the estuary part of the Raba ...
The paper presents the computer program RIVER which calculates a flow capacity of river valley with vegetated floodplains. The program was elaborated in the C programming language. For the mean velocity calculation Darcy-Weisbach formula was used. Velocities, friction factors and the components of discharge in the main channel and on the floodplains were calculated using momentum transfer between the main channel and the floodplains were included in the calculation using Pasche method. The calculation of the discharge rate was performed at a selected crosssection in the Lower Biebrza Basin as an example of this program application. The Biebrza River valley is covered by different types of vegetation as grasses, sedges, reeds, shrubbery and trees. Calculation was performed for a flood event, whose water level was collected during field measurements. ...
In result of considerably diminished retention abilities of catchment area as well of river and stream inundation areas, increased high water flows occurred, particularly in the watercourse mouth sections. It poses a considerable flood hazard for the urbanized areas. Registered flood of July 1977 and June 2001 caused by high waters confirmed significant flood hazard in the areas of Carpathian tributaries of the Vistula River. In the Carpathian Foothills area, because of high water culmination times are shorter, watercourse regulation in closely built-up areas is necessary. Strong urbanization of the riverbank terrains resulting from historical location of towns gives no possibility to design riverbed in character close to natural. One of the main solutions, which is the most frequently applied and guarantees conducting high water flows is heavy consolidation of bed constructed in a shape of a trough. An example of this type of regulation is applied the mouth section of the Naściszówka stream. The Naściszówka inflow to the Łubinka river is situated in the Nowy Sącz city area. The streambed runs along Barska street. The adjacent terrain is characterised by a close urban building. The trough discharge capacity was assessed. According to the design guidelines in „Mountain stream consolidation”, ...
Freshets, by the periodical changes of the hydrodynamic conditions in the river channel, cause its intensive changes. At the time, the occuring fluvial processes have the decisive influence on creation of erosive and cumulative forms in the channel. Dimensions of these forms depend also on sediment transport. This paper presents the results of investigations carried on the Łososina River meander for years 2004–2005. Morphological changes in the channel, created by the 3 freshets, have correlation with the archival data. The bank erosion estimation shows that a cross section of channel has become wider. The changing hydraulic conditions were determined and the sediment transport intensity was estimated. ...
This article presents characteristic of cosinegenerated curve, its equation, shape and curvature. It presents the methodology of curve parameters (minimum radius and curve length) setting witch describe real river bends in map’s co-ordinates. The methodology was used for describing horizontal configuration of river bends down Prosna river section form 94+330 km to 93+660 km located below designed Wielowieś-Klasztorna water reservoir. On the basis of bends parameters numerical modeling of bed topography was made. Results of modeling were compare with results of in situ surveys. The result of model calculations and in situ surveys is horizontal and vertical configuration dependence down investigate river bends. On the basis of surveys results it was set that the calculated river bed topography describes real bed topography in a good way. It was also set that calculated curves corresponds with configuration of river bends. ...
The most important factors causing deep erosion in the river side arm include positive bedload balance and hindered ice progress in the main river bed. Another factor is formation of near-bank channels along high banks or banks covered with high and dense vegetation. Those factors also lead to partial destruction of dams and washing out of silted material. Thus, access of predators to an island is restricted. That provides favourable conditions for natural development and for establishing nature reserves in regulated rivers. ...
The work describes the research on the settlement of the benthic macro invertebrates within different morphological conditions of the mountain stream channel. Along the paper the community structure of benthos was investigated within the point bars area of the Jałowiecki stream in the Makowski Beskid Mountains. To describe the habitat structure, influenced by varied granulometric and hydrologic conditions the research points of the different habitats types of benthic invertebrate were selected. Type 1; located on the top of riffles, type 2; located close To the proximal part of the bar, type 3; located on the opposite river bank within the area of the point bars and type 4; located in the shadow of mega clusters. ...
