Fourth Study Conference on BALTEX Scala Cinema Gudhjem

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Assessment of the Ecological Situation in Small Streams and Lakes in the
Neva Basin under the Anthropogenic Impact of St.Petersburg
Valery Vuglinsky, Tatyana Gronskaya
State Hydrological Institute, 2 nd Line 23,St. Petersburg,
199053, Russia, E-mail:vvuglins@vv4218.spb.edu
Negative effects of the human activity on water resources
and ecology of water bodies are most significant in the
regions of water shortage. Proceeding from this
viewpoint, surface water bodies within the Baltic Sea
basin in the territory of Russia are in rather favorable
conditions because of numerous water bodies available
on the one hand, and because of a poor development of
economic branches requiring much water (irrigation in
particular) on the other hand. Most significant ecological
changes in water bodies are observed in the cities within
this region; these changes are most evident in water
regime changes and in worse water quality in small
streams and lakes. Besides, observation network on small
streams and lakes (monitoring network) is poorly
developed. This is the reason why the assessments of
ecological situation in these water bodies within the cities
are quite limited; they are made episodically and it is
impossible to follow the dynamics of anthropogenic time
changes in water regimes and quality. To estimate the
ecological situation in small streams and lakes within the
Neva basin in St Petersburg and to organize a system of
ecological monitoring of these water bodies appropriate
projects were initiated in 2002 on the initiative of the City
government.
These projects are to be implemented within the
framework of compilation of the water resources
inventory (cadastre) in St Petersburg.
The water fund of St Petersburg since its foundation has
suffered fundamental changes, i.e. more than 80 water
bodies have been created or, vice versa, eliminated
(Vuglinsky et al. (2002). Fig. 1(a, b) demonstrates a
striking example of changes in the hydrographic network
of the city during the 20th century in the catchments of
Lake Lakhta and the River Tchernaya Rechka.
Figure 1(a). Hydrographic network in the catchments of
Lake Lakhta and the River Tchernaya Rechka in 1912 (1,
2, 3 – Lakes Upper, Middle and Lower Souzdalsky; 4 –
Long Lake; 5 – Lake Lakhta)
Figure 1(b). Hydrographic network in the catchments
of Lake Lakhta and the River Tchernaya Rechka in 2000
(1, 2, 3 – Lakes Upper, Middle and Lower Souzdalsky;
4 – Long Lake; 5 – Lake Lakhta; 6 - Orlovsky Sand-Pit;
7- Reservoir on the River Kamenka
Together with the changes in the hydrographic network,
the ecology of water bodies in the city became much
worse, because anthropogenic load on water bodies is
constantly increasing. For example (Gronskaya et al.,
1999), during the last twenty years the total phosphorus
load on Lake Sestroretsky Razliv became 2.3 times
greater (Fig. 2).
Figure 2. Dynamics of phosphorus load to Lake
Sestroretsky Razliv
Besides, the latest official inventory of the water fund in
St Petersburg was accomplished in the late 1950s and
early in the 1960s. Incomplete data on the water bodies of
St.Petersburg, their regime and water quality collected
during the last years don’t provide a reasonable decisionmaking
on the rational use and conservation of streams
and lakes in the city.
Basic objectives for the present research are as follows:
• inventory of water bodies within the territory of the
city (rivers, canals, lakes, ponds, reservoirs);
• assessment of present ecology of water bodies;
• development of scientifically validated
recommendations on the rational use and
improvement of urban water bodies.