Summary:

The paper presents measurement and calculation results of volume samples taken from the bedforms of the sand-gravel bed river in Polish Carpathians. As a sample method the “in situ” sample freezing method was applied. River channel geometry and changes in the morphology of the river bed were investigated using laser geodimeter. The procedures have been carried out on the Raba River downstream of its confluence with the Vistula River. The main research was conducted in spring and autumn 2006. To give a picture of the long term processes which have the influence on the changes of the river bed along the investigated reach for comparison some of the results from year 2005 are also presented. The basic information about research catchment, its location, gravel sampling methodology and characteristics of sand-gravel dunes are included. Development of riverbed forms as a mixture of sand and gravel according to their granulometric composition was detailed. The samples were analyzed considering the layered structure of the dunes and the results of statistical calculations are provided. Tables of granulometric parameters in metric and logarithmic scales are presented among other information such as: mean diameter, sorting index, sorting degree, coefficient of grains uniformity and non-uniformity, standard deviation, skewness, flatness. With this information the genealogy of dune and their mobility along the river bed could be predicted.