Summary:

The paper attempts at evaluating the influence of certain factors (slope gradients and the length of fields, the granulometric composition of soil, the existence of terraces, and the ploughing direction) on the intensity of water erosion (annual soil losses) determined with the USLE method, exemplified by a mountain village of Konina. Konina is situated on the northern slopes of the Gorce Mountains (the range of the Western Beskidy Mountains) in the communes of Niedźwiedź, at about 500 – 1200 metres above sea level. This area is dominated by brown soils formed from sedimentary rocks (sandstones, mudstones, marls) with a clay soil texture: silty clay loam, silty clay, clay loam. Average annual temperature ranges between 6–8oC, precipitation – between 850-950 mm. The intensity of erosion was examined for arable lands, which constitute 63% of all agricultural lands. Arable fields are situated in areas where the slope gradient ranges between 0-5%, at the bottom of the Konina river valley and on mountain ridges, to 40% on steep slopes. The majority of fields are characterised by short slope lines, 10–30 metres on average, 100 metres at the most. The article distinguishes 4 land erosion models, for which regression equations have been calculated. The study reveals, among other things, that for model 1, characterised by steep and short fields, slope terraces and high soil resistance are major factors limiting soil losses. For model 2, characterized by relatively long fields, small slope gradients and perpendicular-to-slope or angular-to-slope ploughing directions are the factors limiting erosion. Within model 3, characterized by short fields, intensive erosion is mainly caused by substantial slope gradients paralleled by a relatively low level of soil resistance. For model 4, characterized by very long fields, erosion is not very intensive, despite the parallel-to-slope ploughing direction, due to their low slope gradient. The analyses of regression coefficients confirm, to a certain degree, the existence of a regularity which says that the longer the field, the lower the influence of the length increase on soil losses. On the other hand, the larger the slope gradient, the higher the influence of the slope gradient increase on erosion. The intensity of erosion is a consequence of influences exerted by various connected factors, whose description requires a system approach.