Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57, 229-234

https://doi.org/10.11118/actaun200957050229
Published online 2014-10-10

Analysis of soil erosion factors in the river-basin of water tank Šance: confrontation of results of methodologies observing soil erosion

Marie Palíková1, Aleš Kučera2

1Ústav geoinformačních technologií, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republika
2Ústav geologie a pedologie, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republika

Soil erosion is still an issue in forestry and in human water-resources activities connected with landscape management and the protection of surface waters. The methods recently assessing the water erosion include: monitoring of suspended sediments in water, monitoring of dynamics of soil pro­per­ties, assessing the inclination of soil towards soil erosion, monitoring of effectiveness of erosion control measures, erosion processes modeling etc. (Buzek, 1981; Buzek, 1983; Holý, 1994; Jařabáč, Belský, 2008).
The river basin of the water tank Šance is very important as a source of potable water and this importance is advanced, when water tank is clogged up by suspended sediments.
Erosion was assessed by two methods in ArcMap 9.3 working with original data: the first method is Universal equation calculating an average annual soil loss from surface (USLE) (Wischmeier, Smith, cit. in Janeček, 2002); the second method assesses the potential erosion (MPE), using specific soil properties as factors, evaluating the rate of the intensity of erosion (Kučera, Palíková; 2009).
Each method uses different ways for the description of the erodibility: USLE describes a long-term average annual soil loss as a consequence of surface erosion. It gives exact values of sediments in t . ha1 . year−1, but from the other point of view, this method is primarily created for an agricultural land. Compared with USLE, MPE solves potential erosion and gives relative values of the erosion tendency of an environment. PME could give a new point of view on the assessing of the erosion.
The river basin Ostravice above water tank Šance was used to compare these two methods. As a control measure, dates of the assessment of the water sediments regime (Buzek, 2001) were used. This observation was pursued in waters of the gagin station ČHMÚ Ostrava in Staré Hamry in according Stehlík (1969). This 25-year process of measuring shows the value of 2.47 t . ha−1 . year−1 in water tank upper Ostravice (with surface 72.96 km2). USLE shows much lower values of suspended sediments (0.41 t . ha−1 . year−1 using a continuous longitude of slopes or 0.11 t . ha−1 . year−1, with regards to the interruption of slopes by the forest roads). This difference is caused by the construction of USLE, which doesn’t respect increased values of sediments after the crossing of fords by the forestry mechanization, rill erosion or inputs of sediments from watercourse and near ravines. Therefore, the high values of suspended sediments are mainly caused by forest management (Buzek, 2001).

References

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