Estimation of water erosion threat of the Smuga stream basin in the Beskid Wyspowy / Ocena zagrożenia erozją wodną zlewni potoku Smuga w Beskidzie Wyspowym

In this work, results of evaluation of potential water erosion threat of the Smuga stream basin in Beskid Wyspowy were presented according to the USLE model and the GIS techniques. The basin area is 5.40 km2; mean height is 636.4 m a.s.l. and mean basin slope is 21.32%. The basin is in a significant part covered by forest which is 54.26%, grasslands occupy 8.15% and arable lands 34.63%. The highest water erosion threat takes place on arable lands with high slopes and defective cultivation. Calculated soil loss is 2078.59 Mg yearly, which gives a unitary loss of 3.85 Mg for 1 ha. This classifies the investigated basin as very low threatened – second class in sixth degree scale.