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 ...
