The natural effects of transverse structures in Gabrovacka reka torrent

Abstract

The classical European system based on the construction of transverse structures is very significant in the solving of the problems of deep and lateral erosion and sediment accumulation in torrent beds. However, due to their effective height on the upstream side, the dams check and accumulate the sediment making the siltation (deposition of silt) whose slope is called the slope of siltation. This paper presents the natural effects of transverse structures (dams) in Gabrova?ka reka, which can be quantified. The paper presents the effects of bed slope on the slopes of siltation and the amounts of accumulated sediment in the siltations, because the effects of technical works are primarily evaluated by the slopes of siltation and by the amounts of accumulated sediment. The analysis of the dependence of newly formed slopes of siltation (Iz) on natural bed slopes (It) was performed by the method of modeling, as the main method, and also by regression and correlation analyses (simple correlation), as concrete study methods. Under the hypothesis that the siltations have a regular wedge, i.e. prismatic form, the accumulated sediment W [m3] in the siltations was calculated by B. Kitin (1975) formula. The study results confirm the very high correlation between the slopes of siltation and bed slope and present the amounts of the accumulated sediment in the conditions of different natural bed slopes and valley widths. This is a useful information which can improve and make more efficient the work on torrent con1rol with similar orographic, petrographic and particle size characteristics.