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.