PART 8
8.1. Conclusion statements
Taking
into consideration the evaluation of the environmental monitoring results of
hydrological year 2000 the Nominated Monitoring Agents concludes:
1. According to the evaluation of observations carried out at the
Doborgaz and Helena profiles it can be stated that the yearly average discharge
released to the Danube riverbed in the hydrological year 2000 was 458.04 m3.s-1.
This means that according to the water management agreed in the
intergovernmental Agreement, signed in 1995, the obligation of the Slovak party
to release 400 m3s-1 in long-term average to the Danube
was fulfilled. The discharge to the Mosoni branch of the Danube and to the
right side seepage canal was 42.32 m3.s-1 (41.12 m3.s-1
+ 1.20 m3.s-1). The amount of water released to the Mosoni
branch of the Danube was fulfilled as well.
2. The water quality in the Danube has not changed by the influence of
measures realised according to the intergovernmental Agreement, signed in 1995.
The changes in water quality during the year refer to the water quality
fluctuation entering the influenced area at Bratislava. The hydrological year
2000 was similar to the previous hydrological year. No extreme values of any
parameters were observed. Water quality in the right side river arm main
branches follows the water quality in the Danube. Its tributaries and pollution
from the settlements on the Hungarian side primarily affect the water quality
in the Mosoni Danube, observed at the Vének profile.
3. According to the evaluation of ground water regimes before and after
realising the water supply, enabled by the technical measures and discharges
according to the intergovernmental Agreement, signed in 1995, it can be
concluded that the water supply has caused significant rise of ground water
levels on the Hungarian territory – effected by the water supply – for low and
average discharge conditions in the Danube, except in the narrow strip along
the Danube riverbed. Comparing the hydrological situation at high discharge
conditions it can be stated that the water supply did not caused a significant
change in the ground water levels. In general it can be stated that the water
supply play an important role in creating ground water levels over the
Szigetköz region.
Increase of ground water levels in the strip along the Danube old riverbed on
both side could be satisfactorily ensured only by increasing water level in the
Danube by measures realised in the riverbed.
4. Based on the long-term data evaluation it can be stated that some
parameters of ground water quality have changed due to the water supply
realised on the Hungarian side. These changes are not significant and do not
cause changes in the classification for drinking water supply. They are mainly
connected with changes in ground water flow direction. In general, it can be
concluded that the water quality parameters in the drinking water wells are
stabile on both sides.
5. The average soil moisture values in the hydrological 2000 were lower
in comparison to the previous year. However, the deeper layers on most of the
observation points on the Hungarian side were moisturised by the ground level,
increased by water supply. The soil moisture of the upper part of soil layer
showed a deficit of moisture due to the low amount of precipitation, especial
in the second half of vegetation period. The position of ground water level did
not allow moisturising of the shallow soil profiles in the upper and middle
Szigetköz.
The situation was similar also on the Slovak side, but during artificial flood
simulation increased ground water levels supplied the soil moisture during the
vegetation period.
6. The forest stands on the Slovak side consist of willow and
cultivated poplar. The yearly increment in the year 2000 of the willow stands
remained on the stabile level. The health state of the willow stand in the
evaluated year remained good. The cultivated poplar stands are widely spread in
the inundation area. On most of the monitoring area reached the age of cutting,
but the increment values decreasing only slowly and the growing is satisfactory.
Height increments on most of them still meet the curves for the I. growth class. The values of weekly girth growth measures prove the positive influence
of the artificial floods on some of the monitored areas, as well as the
significant influence of precipitation at the beginning of the vegetation
period. Raising the water level in the Danube old riverbed could mitigate the
negative influence of insufficient precipitation, especially at the beginning
of the vegetation period.
The composition of forest stands on the Hungarian side is similar to that on
the Slovak side. However, the increments of willow stands and forest stands on
shallow soils lag behind the expected growth rate. In general the health state
of poplar stands was very good, but on the other hand, the willow stands,
especially on the upper and middle part of the Szigetköz, were characteristic
by middle health condition only. The unfavourable moisture conditions,
especially when low amount of precipitation occur during the vegetation period,
could be improved by increasing of water level in the Danube old riverbed.
7. On some of the monitoring areas in the last years signs of changes
in the phytocoenological communities could be noticed. All of these areas are
strongly influenced by anthropogenic impacts (cutting the forest). In general
the same species remain dominant during the observation period. Only the values
of dominance are changing. On the monitoring sites in the area influenced by
the drainage effect the hygrophilous species are replaced by species tolerant
to drier conditions. The drying was stopped on several sites where the
introduced water supply is sufficient. However on several monitoring site there
were observed higher number of species characteristic for drier biotopes. In
the tree and shrub layer there were no significant changes observed in the last
years. Signs of rearrangement were detected on sites affected by the drainage
effect near the main riverbed. Considering the terrestrial molluscs it can be
stated that on most of the monitoring sites original hygrophilous species are
returning. Changes in aquatic fauna reflect the changes in the river arm system. Generally it can be stated that along the water supply path the number
of species rose; the number of rheophile species increased. The species
composition became stabile. In the ichtyofauna reappearance of some rheophile
species reflects the partial reconnection of the right-side river branch system
with the main riverbed. The characteristics of fish community on monitoring areas
supplied by water are comparable to the results obtained before damming the
Danube.
8.2. Proposals
1. The experts of both Parties will carry out field documentation of
monitoring points or wells added or changed in the frame of surface or ground
water level monitoring.
2. The experts will study the EU 2000/60 Directive in water policy from
October 23, 2000 and will consider the needs and possibilities to apply it in
the frame of surface water quality evaluation.
3. The Hungarian Party will propose to include relevant monitoring
sites in the frame of surface water quality monitoring, existing and observed
in the Danube main riverbed on the stretch between Rajka and Sap (rkm
1848-1811).
4. Due to the decrease of number of forest monitoring areas on the
Hungarian side the experts of both Parties will revise the list of existing
monitoring areas. The Hungarian side prepare a list of monitoring areas from
which the experts will select areas available for purpose of the joint
monitoring. A new list of actually observed or proposed areas in the frame
of joint forest monitoring will be prepared by November 2001.
5. In the frame of biological monitoring the experts will prepare
a long-term evaluation of the agreed groups of biological monitoring
according to the jointly agreed methodology.