Summary:

The Smortawa River, the right-hand sided tributary of the Odra River, is a typical lowland river which sources are located at 175 m a.s.l. south-east from town Namysłów. The mouth is located in km223–350 of Odra River, on 124 m a.s.l. near town Jelcz. In the lower and upper course the river is improved and in the middle course it has kept its natural character. At present according to Water Frame Directive and Polish Water Law we are obliged to create an assessment of ecological state of rivers. One of elements of this assessment is the analysis of hydromorphological parameters variability as supporting parameters for biological assessment. In the article the characteristic of hydromorphological parameters by polish methods of Ilnicki and Lewandowski are are introduced. They describe the changes of these parameters on every separete research section. Moreover with the help of the probability analysis by the Ward method, the similarity is estimated among studied hydromorphological parameters.