Methane ebullition from Czech freshwater reservoirs

Methane is a non-toxic colourless gas created by decomposition of organic materials in anaerobic environments. Such processes take place at bottoms of rivers, dams and water reservoirs. The gas is then released to atmosphere where it contributes to the greenhouse effect. The aim of this thesis is to measure the ebullition flux of methane from selected water reservoirs Vranov and Vír (representing typical water reservoirs in the temperate area), analyze factors affecting ebullition, and compare the ebullition flux among these two reservoirs. The data were obtained via device Simrad EK60 split beam, preprocessed in software Sonar 5, and subsequently analyzed in statistical software R. While there is a great degree of variability of ebullition flux within segments of individual water reservoirs, the total ebullition flux is comparable in both water reservoirs (Vranov: 3,90 ml·m-2 ·d-1 , Vír: 4,22 ml·m-2 ·d-1 ) and not significantly different from each other (p = 0,40). When analyzing possible factors affecting ebullition; the water depth and the distance from the dam, it is necessary to take into account that these two variables are highly correlated which may hinder our ability to separate their effects. Indeed, in both Vranov and Vir the effects of these variables, while significant when studied..