The paper describes geometric internal granulometric structure of lowland river bed forms called sand river dunes. Dunes are typical features associated with sand river bed and studies of processes connected with their formation are essential in understanding fluvial processes within the catchment. Also the knowledge of sedimentary structure and morphology of dunes are important for geologists and paleogeologists to interpret how sedimentary rocks were deposited. Also, in the time of changes of global and local climates, frequent changes of water regime in river could be noted when the development or not-development of river bed-forms can have an important influence on quantity of sediment moving in rivers and water reservoirs built on such rivers. The work was set up on the Rhine River in Germany close to Niderwalluf. The research conducted on the Rhine River involved many of research equipment and river vessels is very rare and unique in the world as far as fieldwork is concerned. Within a paper it is show, that the Rhine River Dunes do not reach the height H which would be expected by the water depth which is responsible for their formation. There could be a couple of reasons for such situation. One of those ...
The paper presents very important, both from practical and theoretical reasons, problem of forming the river bed-forms within the gravel-bed mountainous riverbed and the influence of those bed forms on the discharge value. In natural rivers, due to the complicated nature of the discharge and changes in the water level, the bed forms are quite complicated structures. Those forms are changing in length and height and when present they change hydraulics conditions of the discharge. They could be both 2-dimentional and 3-dimentional, situated in all pars of the cross section. Up to now there are only a few notes and papers about the gravel bed forms which can be found in rivers. Most of scientific papers focus on sand riverbed forms. The present paper shows and concentrates on the field measurements of gravel bed forms found in the estuarial part of the mountain river - the Raba River - in Polish Carpathians. Such research was carried out first time in Poland. The research focuses here mostly on geometrical parameters of these bed forms such as height, length, stoss and trough angle as well as granulometric characteristics of gravel built those forms. Basing on in-site measurements many different hydraulics ...