The Efficiency of a Simple Stabilization Structure in a Water Reservoir

Abstract

IntroductionBrno Valley Dam on the Svratka River (56.19 km) was put into operation in 1940 to decrease the damage caused by river flow during floods, to supply water to the city of Brno, and to control the flow under the dam. The area of the water reservoir is 259 ha with a total volume of 17.7 million m 3 . The banks of the reservoir in the Osada area are continuously damaged to an approximate length of 250 m, where the slope-to-vertical abrasion caverns reach heights of up to 5 m (detailed localization GPS: the banks from 49°14'44.063"N, 16°30'22.781"E to 49°14'45.298"N, 16°30'11.502"E).Pol. J. Environ. Stud. Vol. 27, No. 2 (2018), 793-799 AbstractThe Osada Recreation Area on the left bank of Brno Valley Dam (Czech Republic) represents a location that is extremely affected by the abrasion process due to a combination of adverse factors (fetch related to the dominant wind speed and direction over the water surface causing wave motion, the geological structure and morphology of banks, boat traffic). Our research focused on confirming the hypothesis that properly designed low-cost biotechnical structures can contribute to the active stabilization of a bank under special protection status. The hypothesis was verified by the method of wave train analysis (to prove wave height reduction) and spectral analysis (to prove wave energy dissipation due to breaking) of synchronized data collection of wave motion. The records of water surface motion were taken with the aid of electronic devices on the windward and leeward sides of the structure specifically assembled for the purposes of our research. Comparing the results of both sensors proved the effect of the stabilizing structure (double willow wattling) consisting in wave height and peak spectral energy density reduction. The leeward values decreased to approximately half the windward values due to the process of waves passing through the structure and energy dissipation.

An Investigation of the Bacterial Influence of Acidithiobacillus Thiooxidans on Concrete Composites

“…Sulfuric acid appears in different aspects: from industrial wastewater, within a sewage system, e.g. water, wastewater, storm water [3][4][5] which can be contaminated with organic and inorganic compounds [6,7] and also from groundwater. An acidic attack may also occur as a consequence of bacterial activity which is able to produce acidic products like hydrogen sulphide or sulfuric acid.…”