VERTICAL TEMPERATURE PROFILE AND DISSOLVED OXYGEN IN KARDZHALI DAM, BULGARIA

Angelina Ivanova

Abstract: The vertical temperature profile and temperature distribution patterns of water and dissolved oxygen in the Kardzhali dam were studied between July and October 2015. The average surface water temperature in the dam varied between 19.2 оС and 29.0 оС within the studied period. According to results, the thermal stratification had an effect on dissolved oxygen distribution and saturation level. At the time of the summer stratification, metalimnetic oxygen minimum was observed. The data demonstrated that the metalimnetic oxygen minimum was present in mid-July at a depth of 15 m to 20 m, and it September it became broader attaining depths from 15 m to 25 m. It was established that the depth of the metalimnetic oxygen minimum followed and was associated to the temperature gradient and the thermocline zone. The oxygen minimum zone was differentiated, being more obvious from the tail towards the wall of the dam.

Keywords: amount of dissolved oxygen; Kardzhali reservoir; monitoring; stratification; thermocline depth; water temperature

Date published: 2018-05-29