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This study is a broad and critical review of the transdisciplinary literature on the construction of culverts and their impacts on stream hydrology and geomorphology as well as on stream habitats and biota. For engineers, a culvert is a structure, usually of the tunnel type, that transfers a stream or open drain under a road, railway line, or other obstacle from one side to the other. In fact, culverts are complex hydraulic structures whose impacts on stream ecosystems must be evaluated and understood before they are designed. The objective of this paper is to analyse and discuss recent knowledge about culvert functioning in terms of their negative effects on the passage of freshwater biota, particularly fish, and on entire stream ecosystems. We present the results of many studies showing that improperly designed culverts are barriers for migrating animals and usually have serious ecological consequences (mainly disturbances to fish life history). We also pay attention to different culvert modification methods that increase their passability for organisms and mitigate the impacts of culverts on the surrounding environment. The other purpose of this review is therefore to emphasize that the integration of the knowledge and professional experience of biologists and ecologists with those of river managers, river engineers, hydraulic engineers, hydrologists, and geomorphologists is necessary to design culverts that preserve the natural properties of streams. Key words: road-stream crossings, river fragmentation, fish migration, passage effectiveness, knowledge integration. La presente etude est une synthese large et critique de la litterature transdisciplinaire sur la construction des pon-ceaux et leurs impacts sur l'hydrologie et la geomorphologie des cours d'eau ainsi que sur les habitats et le biote des cours d'eau. Pour les ingenieurs, un ponceau est une structure, generalement de type tunnel, qui transfere d'un cote a l'autre un cours d'eau ou un drain ouvert sous une route, une voie ferree ou un autre obstacle. En fait, les ponceaux sont des struc-tures hydrauliquescomplexes dont lesimpacts surles ecosystemesdes coursd'eau doivent etre evalues et compris avant leur conception. L'objectif de cet article est d'analyser et de discuter des connaissances recentes sur le fonctionnement des ponceaux quant a leurs effets negatifs sur le passage du biote d'eau douce, en particulier les poissons, et sur les ecosystemes entiers des cours d'eau. Les auteurs presentent les resultats de nombreuses etudes montrant que les ponceaux mal concus constituent des obstacles pour les animaux migrateurs et ont generalement de graves consequences ecologiques (princi-palement des perturbations du cycle biologique des poissons). Ils portent aussi leur attention sur les differentes methodes de modification des ponceaux qui permettent d'augmenter leur facilite de passage pour les organismes et d'attenuer les impacts des ponceaux sur le milieu environnant. L'autreobjectif decette synthese est donc desouligner que l'integration des connaissances et de l'experience professionnelle des biologistes et des ecologistes avec celles des gestionnaires de cours d'eau, des ingenieurs fluviaux, des ingenieurs hydrauliques, des hydrologues et des geomorphologues est necessaire pour concevoir des ponceaux qui preservent les proprietes naturelles des cours d'eau. [Traduit par la Redaction] Mots-cles : traversees de routes et de cours d'eau, fragmentation des cours d'eau, migration des poissons, efficacite du passage, integration des connaissances., Introduction The fragmentation of stream systems by human-made barriers is a major cause of losses in river ecosystem integrity and of changes in aquatic biodiversity worldwide (Agostinho et al. 2004; [...]

Two sets of triangular hydrographs were generated in a 12-m-long laboratory flume for two sets of initial bed conditions: intact and water-worked gravel bed. Flowrate ranging from 0.0013 m3 s-1 to 0.0456 m3 s-1, water level ranging from 0.02 m to 0.11 m, and cumulative mass of transported sediment ranging from 4.5 kg to 14.2 kg were measured. Then, bedload transport rate, water surface slope, bed shear stress, and stream power were evaluated. The results indicated the impact of initial bed conditions and flow unsteadiness on bedload transport rate and total sediment yield. Difference in ratio between the amount of supplied sediment and total sediment yield for tests with different initial conditions was observed. Bedload rate, bed shear stress, and stream power demonstrated clock-wise hysteretic relation with flowrate. The study revealed practical aspects of experimental design, performance, and data analysis. Water surface slope evaluation based on spatial water depth data was discussed. It was shown that for certain conditions stream power was more adequate for the analysis of sediment transport dynamics than the bed shear stress. The relations between bedload transport dynamics, and flow and sediment parameters obtained by dimensional and multiple regression analysis were presented.

One more time we would like to pay attention of especially of the hydraulic engineer audience to bankfull stage and discharge. Along the paper we show commonly accepted definitions of it and ways of calculations. It is difficult to determine the size of the bankfull flow level, that is why the authors are presenting many selected methods. Some of the methods allow the determination of biotic bankfull flow through the occurrence of zones of vegetation characteristic and based on the observation of the occurrence of ground beetles (e.g. the Woodyer and the Radecki-Pawlik and Skalski methods). Some of the methods – most popular- are using morphometric parameters (e.g. the Williams, the Hey and Thorne, the Gauckler-Manning and finally the Lambor methods).

W artykule przedstawiono wielkość zmian odpływu powierzchniowego w wyniku przyszłych planowanych zmian użytkowania rolniczego zlewni. Badania prowadzono w obszarze Winnej Góry znajdującej się w miejscowości Mściwojów (województwo dolnośląskie) w zlewni zbiornika wodnego Mściwojów.

Mountain stream gravel is very often legally and illegally mined and gravel is removed from river beds sometimes on the very large scale which is disastrous for fluvial situation of rivers, for river ecology and river engineering works done for flood protection such as river revetments, bridges and all hydraulic structures. This situation makes a big problem for all river managers. Thus gravel mining of the mountain streams in the Polish Carpathians is the subject of many scientific studies when we observe river problems, but also it has a place in Slovakia. This paper deals with such problems additionally showing examples of such bad practices.