Режим на алкалността на черноморските води и неговото антропогенно изменение във Варненския залив

А. Рождественски. Режим на алкалността на черноморските води и неговото антропогенно изменение във Варненския залив

A. Rozhdestvenski. Regime of alkalescence in the Black Seawaters and its anthropogenic changes in the bay of Varna

---

REGIME OF ALKALESCENCE IN THE BLACK SEA WATERS AND ITS ANTHROPOGENIC CHANGES IN THE BAY OF VARNA

A. Rozhdestvenski

(Summary)

Alkalescence of natural waters implies the dominance of strong bases ovier strong acids. In fact alkalescence is predetermined by biocarbonate and carbonate content in the water. In depth the Black Sea waters contain hydrosulphides as well. The salts of weak acids are in very small quantities.

The Black Sea waters have high alkalescence, obviously prevailing over that of the other seas and oceans. The average alkalescence of the Black Sea surface waters is above 3.3 mg eqv/l while in depth it is even more than 4 mg eqv/l. Three are the main reasons having caused this high alkalescence: river run-off, evaporation and vertical water mixture with the sulphuretted hydrogenie waters below under the circumstances of partly reversible processes of restoring the former content after oxidiring the sulphuretted hydrogen.

Alkalescence of the surface sea waters throughout a year has quite often min values in May mid max at the end of autumn or during the first winter months due considerably to the Danube flow.

In the Bay of Varna the alkalescence average value of surface waters is 3.41 mg eqv/I. Sometimes its absolute max is over 3.80 mg eqv/l, influenced by the lake current. Recently it has been dropping more and more as follows: 1955—1963 the average alkalescence value was 3.37 mg eqv/l, 1964-1971, 3.33 mg eqvo/l 1972—1976, 3.32 mg eqv/l.

Some anthropogenic factors such as the algae flowering which is a source for polluted water self-purification and the running of waters with low alkalescence through the town’s water supply system, diminish the sea water alkalescence in the Bay of Varna. In the lake of Beloslav its average value is 5,70 mg eav/l which m the last few years went down.

---

Към съдържанието на статията/ Access to the full text of the article