Author(s): Julie Winterova; Josef Krasa; Miroslav Bauer; Tomas Dostal

Linked Author(s): Josef Krása, Miroslav Bauer, Tomáš Dostál

Keywords: Watershed; Water erosion; WaTEM/SEDEM

Abstract: The Czech landscape has undergone various changes over the last 100 years. Although the predominantly agricultural use of the area has been preserved, the appearance of arable land and adjacent land has changed. After a long-term intensification of agriculture, meadows are slowly returning, some extinct ponds have been restored and new water reservoirs have been built. Nevertheless, the landscape is mainly adapted to economic purposes, and this has its effect, among other things, on the clogging of reservoirs with sediment. Vrchlice Reservoir is used to supply drinking water for around 50,000 inhabitants and increased income of sediment has been detected there. An analysis of land use showed that there have been no significant changes in the representation of land-use categories in the last 100 years that would significantly affect erosion processes in the river basin. Water erosion and sediment transport were modeled with WaTEM/SEDEM. To control the outputs of model, sediment volumes in 8 ponds were measured using simple injection method. In Navesky, Steklik and Hamersky pond, the results given by model were approximately the same as measured. There were larger differences in the ponds on the Opatovicky stream, where the model significantly underestimated the supply of sediment to the reservoirs compared to the measured volumes. The cause may be the high content of old sediment, erosion from adjacent forests and the fallout of organic material from the banks. Nevertheless, it was possible to mark areas that contribute significantly to the sediment transport into watercourses and to introduce erosion control measures there. This study is supported by H2020 project SHUi (773903). The support is highly acknowledged.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221513

Year: 2022