Fourth Study Conference on BALTEX Scala Cinema Gudhjem

The structure of water bodies cadastre of the city
envisages two independent sections: rivers and lakes. The
following blocks are common for these two sections:
hydrological, hydrochemical and sanitary-bacteriological,
as well as blocks containing hydrographic information
about water bodies and data on their use. Information on
lake hydrobiology makes it possible to estimate their
trophic level.
The first stage of work includes water bodies inventory
on the basis of updated topographic maps (scale 1:10000)
and GIS technology. The following is to be prepared
during the first stage:
• a list of all lakes and streams reliably estimated
from the maps of selected scales;
• coordinates of each water body;
• calculation of lake water areas and stream lengths;
• selection of water bodies to be studied in more
details;
• a list of characteristics to be studied under field and
laboratory conditions.
The second stage includes field surveys of the selected
water bodies, their descriptions and measurements of
basic hydrological characteristics; water and bottom
sediment sampling; biological, sanitary and
bacteriological analysis. Low-water period in summer
characterized by the most unfavorable ecological
conditions in water bodies is the optimal time for the
second stage implementation.
The third stage includes laboratory analyses of water and
bottom sediment samples. Methodologies recommended
by standard documents of ROSHYDROMED and
Ministry of Health of the Russian Federation are to be
applied during the second and third stages of the Project
implementation.
During the fourth stage an electronic database on water
bodies in MS Excel, MS Word and MapInfo formats is
to be prepared. During the fifth stage the research
materials are to be scientifically generalized; conclusions
are to be made on the present ecological situation in
water bodies and on the ways to improve it.
As examples, several tables are given below containing
information about hydrological, hydrochemical,
hydrobiological and bacteriological characteristics of the
River Okhta and Lake Lower Souzdalsky prepared from
the results of small water bodies inventory in the
downstream area of the Neva basin in 2003 (Tables 1-5 ).
Table 1. Lakes’ morphometry and hydrology
Lake name Catchment
area,
km 2
Lake
surface
area,
10 3 m 2
Water
storage,
10 6 m 3
Mean
depth,
m
Lower
Souzdalsky
25.8 736 1.87 2.5
Lake name Annual level change, m
Lower Souzdalsky 0.5
Table 2. Rivers’ hydrography and hydrology
River name
Catchment area,
km 2
Total In the
city
Length
in
the city,
km
Discharge
(during
sampling)
m 3
Okhta 768 85 14.3 1.41
- 177 -
Table 3. Water quality by hydrochemical
characteristics
Lake/River
name
Water
temperature,
C 0
pH Dissolved
oxygen,
mgl -1
BOD 5,
mgO2l -1
Okhta 21.2 6.75 5.2 0.83
Lower
Souzdalsky
26.3 7.2 10.9 1.12
Lake/River
name
N-
NH4,
mgl -1
N-
NO3,
mgl -1
N-NO2,
mgl -1
Total
P,
mgl -1
Okhta 0.4 6.5 1.37 0.33
Lower
Souzdalsky
1.0 0.2 0.01 0.07
Lake/River
name
Cu,
mgl -1
Mn,
mgl -1
Oil,
mgl -1
Water
quality
class
Okhta 0.005 0.045