Dlouhodobý pokles vlhkosti půdy v zóně aerace v povodí Čižiny v okrese Bruntál

Anotace: In this publication an electrochemical method – chronoamperometry is presented, which monitors a time response of the current after the imposed DC voltage. The aim was to determine soil moisture for purposes of hydrology. Voltage of 4.5 V was applied and the current value in the given location was in the order of magnitude of mA. Steel electrodes were sunk in soil into the depth of 0 ÷ 0.6 m and 1.1 ÷ 1.4 m. The soil in question was loamy-stony podzolic soil in the Low Jeseník Upland. The results of these experiments have shown that the minimum rainfall amounts of 0.5 ÷ 1 mm can be observed, soil moisture in the order of magnitude of tenths of percentage can be determined and the moisture change of 1 % corresponds to the change of the current value of 8%. The results of the measurements of moisture in the depth of 1.1 ÷ 1.4 m during summer months in 2012, 2013, 2014 and 2016 exhibited a considerable decrease in soil moisture. In 2016, recurring periods with large amounts of rainfall were followed by periods with rainfall deficiency.