ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

depositional velocity of CaC0 3 • Underground water in caves
exist in a state of large volume but with a small waterair
interface. When it flows to surface as discharge, the water
shape will change into a state of large interface but with
shallow depth, which result in tufa deposition. Much continental
CaC0 3 deposition may be formed in this way.
SERGEY S. CHERKASHIN
On the Black Sea level changes along the shores
of Odessa Bay during past century
Geography Department, State Mechnikov University,
Dvoryanskaya St. 2,270000 Odessa, Ukraine
Odessa Bay is situated on the Northern coast of the Black
Sea. The .length of the Bay shoreline constitutes 14.5 km
between capes Langeron and Nothern. The Southern part
of the bay occupied by Odessa sea port along 5.7 km. The
remaining 8.8 km - though natural, but greatly developed
shores within urban boundaries of Odessa. 5.4 km of them
represent doubled barrier Khadgibey and Kujalnik limans,
the remaining 3.4 km are occupied by active abrasive-landsliding
cliff. The given topic is of important practical significance'
though Odessa Bay coast is on the territory of
Odessa City as one of biggest cities in Ukraine, are intensively
developed and densely built on.
The sea port is the greatest in Ukraine. It territory is situated
along the part of the Khadgibey liman barrier, and at
the foot of high stable shore slope (up to 45 m) on marks
2-5 m above the zero-water level. The active abrasive-landsliding
cliff, about 50 m high, is located in the north-eastern
part of the bay. It is subjected to the action of landslides
and the rate of its foot retreat constitutes from 0.2 to
3.5 m/year during different years. The shorelines of liman
barriers are low, their height equals 1-2 m above average
the sea level; the level of limans is 2-4 m lower than the sea
level. Along the bay shore drift flow ends, with the capasity
20,000-30,000 m'Zyear. That is why the shoreline of barriers
is stable in general. Clayey benches are located on the
nearshore bottom in the north-eastern part of the bay opposite
the active cliff (the average inclination 0.0013). The
main part of the bay bottom is represented by underwater
sandy part of the barriers, its inclinations are within
0.0035-0.0046. Such inclinations are favourable for coming
of sandy drifts to the shore (beach) during storms, which is
also favoured by dumping of alongshore drift flow in the
bay. The characteristic of the hydrometeorological regime
of the sea is done by the data of marine station «Odessa­
Port», on which instrumental measurements have been
carried out since 1870. The following changes are pointed
out: a) short-term level changes, caused by hydrometeorological
reasons (mainly by wind); b) long-term, caused by
the influence of hydrocratic and geocratic reasons (mainly
by changes of sea water balance and vertical movement of
coastal blocks of the earth crust). Short-term level changes
connected with wind set up and wind tide phenomena are
conditions by the activity of strong winds, maximum amplitude
reaches 2.26 m, absolute maximum of wind set up
being 1.52 m, absolute maximum of the wind tide being
-0.74 m. The average annual amplitude 500/0 providedness
equals 0.52 m. Seiche fluctuations, the amplitude of which
reaches 0.5 m, can be put on these values. Summary generalized
rates of wind set up and wind tide rise and fall of
the sea level usually are within 2-6 em/hour (maximum
25.7 em/hour). In such conditions the profile of the coastal
zone changes very quickly, and it is obviously adapted to
such intensive changes. But storm surges increase of the level
sharply increases rates of cliff retreat and beach erosion,
as during very short time enourmous amount of wave
energy dissipates near the shore.
The increase of the general humidity of the Black Sea basin
activized eustatic level rise to the average rate 2.67
mm/year. Relative vector rate equals 2.91 mm/year during
1926-1990. Against this background during 1921-1949 the
rate of the rise turned out to be equal 0.9 mm/year, in
1950-1973 it was already 4.5 mm/year, and in 1974-1991
rate was 6.3 mm/year. No sure prognosis up to 2050 and
the more so up to 2100 can be given, as the rhythms of level
changes have not been studied yet. However three
main scenarios of the level elevation values up to 2100 can
be probable: low up to 0.5 m, middle up to 1 m and high
up to 1.5 m.
If these scenarios become real and storm activity of the
Black Sea increases, by the end of the next century there
will appear the real threat to the Odessa Bay shores, accordingly
to their structure and dynamics. Most probable the
rate of abrasion of clayey landsliding cliff in the north-eastern
part of the bay will grow, normal work of the Sea
port can be disturbed. As alongshore drift flow is fed
mainly by the sediments from abrasive destruction of cliffs
and benches, more drifts will move to the Odessa Bay
from Eastern coastal sector, the sandy bottom erosion opposite
the barriers of Khadgibey and Kujalnik limans will
bacome more intensive. In these conditions the adaption
of accumulative forms to the level rise and increase of their
dimensions are most probable. The rise of underground
water level and lithodynamical influence on the port constructions
will play certain role as well.
SaRIN CHEVAL
.Relations between the climate and the morphology
of the south Dobroudja Plateau.
Special view on the impact of the climatic hazards
Institute of Geography, Romanian Academy,
12 D. Racovita St. sector 2, 70307 Bucharest, Romania
Besides other factors influencing the aspect of a regional
relief, the climatic ones occupy a very important place.
113