VITUKI ILLUSTRATIVE SHORT REPORT OF VITUKI

Transcription

1 VITUKI KÖRNYEZETVÉDELMI ÉS VÍZGAZDÁLKODÁSI KUTATÓ INTÉZET Kht. ENVIRONMENTAL AND WATER RESOURCES RESEARCH CENTRE Plc. Maps of sampling networks of VITUKI in Szigetköz with the illustration of sample taking ILLUSTRATIVE SHORT REPORT OF VITUKI LIFE SZIGETKÖZ Project (LIFE4ENV/H/382) Main topics: Task 3 Assessment of the state of the aquatic environment in the Szigetköz plus contributions to other tasks with modelling and strategy analysis) A side arm of the Zátonyi Danube and the Lake of Lipót with the VITUKI team sampling in the electrically driven wetland boat bought for the project Budapest, 27. December

2 Main activities of VITUKI were focussed at Task 3 Assessment of the State of the Water- Environment in the Szigetköz and evaluation of former and currently planned water-environmental management strategies and interventions. First we reviewed the history of Szigetköz with main emphasis on that of the diversion of Danube. A very condensed version of the history is described below, illustrated with pictures of the history of Danube s diversion. Danube s dried main channel after diversion with inserts of the space view of Dunacsúny/Cunovo Dam, the general arrangement of Variant C, the Dunakiliti Dam with the major revitalisation structure, the bottom sill and a view of the off-floodplain new flow supplementation main structure the Parlagnyilasi Canal The flag of the environmentalists opposing the Project Bős-Gabcikovo-Nagymaros-Hydropower- Sytem (BGNHS) was used, with a vitally important success, as the main flag of the anti-soviet movements leading the Hungarian nation (and later whole Eastern Europe) to freedom. An auxiliary consequence of this globally deterministic and nationally vital but highly non-professional politicalenvironmental movement was the single-sided termination of the international treaty on the building of the scheme BGNHS, by the Hungarian partner. Unfortunately, however, this action also meant that the possible worst solution for Hungary was implemented, when the Slovak partner constructed the dam unilaterally on its own territory (called the Variant C ). It was the worst solution for Hungary from the viewpoint of both the environment and of the economy of Hungary, resulting in catastrophic impact on the aquatic and terrestrial ecosystems of the braided river system of Szigetköz, one of the last remnants of the once vast floodplain ecosystems of Europe. 2

3 For the evaluation of the state of the aquatic environment we have reviewed the printed and web literature. The most important part of this work was the field-sampling programme, which lasted for 3 years and included all water types of the Szigetköz, on the flood plain and in the protected side. Our filed programme, illustrated above with maps of sampling network and below with some data of water quality and the biota, allowed us to draw some important conclusions: koncentráció (mg/l) Mosoni-Duna Oldott oxigén koncentrációk alakulása 25-ben (június, július, október) VI. sz. zsilip Rajka Feketeerdő Halászi Mecsér Dunaszeg Győr Vének kiváló jó erősen szennyezett vízminőségi osztálybasorolás (MSz 12749) koncentráció (mg/l) Mentett oldali vízpótló rendszer Oldott oxigén koncentrációk alakulása 25-ben (június, július, október) Zátonyi Duna Doborgazsziget Nováki csatorna Arak Nováki csatorna Novákpuszta Lipóti tápcsatorna Hédervár-Vadaskerti csat. Zselykei csatorna Mecsér Szavai csatorna Vámosszabadi Szavai csatorna Kisbajcs kiváló jó tűrhető vízminőségi osztálybasorolás (MSz 12749) Duna Rajka Duna Dunakiliti fenékküszöb felett Duna Dunakiliti fenékküszöb alatt Copepoda Cladocera Rotatoria Duna Ásványráró Mosoni-Duna VI. zsilip Mosoni-Duna Feketeerdő Mosoni-Duna Mecsér Mosoni-Duna Dunaszeg Szivárgó-csatorna I. zsilip Ásványi-Duna zárás B-11 Szivárgó csatorna II. zsilip Zátonyi-Duna Doborgaszigeti strand Nováki-csatorna Arak Lipót-Hédervári-csatorna Hédervár Parlagnyilasi-csatorna Keresztfai-zsilip Parlagnyilasi-csatorna új meder Zsejkei-csatorna Ásványrásó Helenai-ág Dunakiliti Bodaki-ág B-7 felvíz Remetei-mellékág Dunaremete Zsejkei-csatorna Mecsér Szavai-csatorna Vámosszabadi Szavai-csatorna Bácsa Zámolyi-csatorna Győrzámoly Egyedszám ANNELIDA GASTROPODA LAMELLIBRANCHIATA MALACOSTRACA INSECTA Szivárgó-cs., I. zsilip Helenai-ág, Dunakiliti Bodaki-ág, B-4 Bodaki-ág, B-7 Remetei-mellékág, Dunaremete Ásványi-Duna, B-11 Ásványi-ág, Z-12 Öntési-tó Ásványi-kikötő Ásványi-Duna, Árvai-zárás Illustration of VITUKI s field sampling results with dissolved oxygen, zooplankton and macroscopic invertebrate data We have found and demonstrated it with detailed measurement data, that the water supplementation system established by the water engineers (Partner 2 EDUKOVIZIG) in the Upper Szigetköz with the help of many engineering structures of which the bottom sill and the Dunakiliti dam were the main ones, had favourable effects on both the water quantity and water quality and ecological conditions of the water systems concerned, much improving the catastrophic conditions that were created by the diversion of the Danube. The visually also attractive aquatic ecosystems of the already revitalized upper part are illustrated by the photos below: Bagoméri-ág 3

4 We have also demonstrated by field data that the water supplementation system opened during this project helped the improvement of the ecological state of the water system in the lower side of the off-levee Szigetköz region. We might also state that these ecosystems were saved in the nearly last days. The flow supplementation turned a dying weed-covered canal into a biologically diverse one (although still in danger of monoculture-macrophyte desertification as shown in the picture below): It follows from this statement that it is very urgent to continue revitalisation by water supplementation in the Lower Szigetköz both in the floodplain and in off-levee protected side. It must be also stressed that even better conditions can be created with the sound ecohydrological operation of this system. To this however Uthe field investigations must be continued Uto monitor the changes and means of better controlling flows and nutrient fluxes shall be provided for assuring long term ecological sustainability. Therefore the major objective of further work should be to provide further supply of flows (and rise of water levels) in the lower part of the system, as the lower part is still in dying-drying condition as shown by the photographs below: In designing these remedial strategies, one should be aware of the fact that at low flows and warm periods many parts of the water system is facing sever (depleted) dissolved oxygen conditions, also in association with the high nutrient (phosphorus) concentrations (decay of dead algae and/or macrophyte masses and respiration of plants). This means that when- and wherever possible larger water surfaces and/or adequate flow velocities should be provided to improve reaeration. This latter (higher flow velocities) must, however handled with care (especially on the off-levee canal and lake systems), as too high or lasting higher flow velocities might harm the presently diverse swamp-like or wetland ecosystem, turning them into less diverse fluvial ecosystems. 4

5 Also the results of our computer modelling work indicated the danger of eutrophycation (hypertrophication) due to the still high plant nutrient concentrations and the low flows, especially in summer periods. Therefore the technology of ecohydrological revitalisation that was described in the Technology report shall also include the provision of the ability of changing flows, flow depths and tailoring also their quality. This suggests the need for creating new ecohydrological storage and flow governing capacities, especially in the off flood-levee protected area, where artificial wetlands (similar to the existing Lake of Lipót, see space image and photograph of VITUKI team sampling below) could help to tailor both water quantities and qualities to the needs of the adjoining ecosystem. The main advantage of the above shown type of created or recreated wetland based regulation is that flows released from the floodplain side via siphons, sluices, etc. could provide for additional flow supplementation of the off-levee protected side (being presently in lack of sufficient flows). Simultaneously, the wetland will retain some of the nutrients, efficiently contributing with it to the improvement of the ecological state of the system, now endangered by eutrophycation. There are several sites that could, in principle, serve for such artificial wetlands (one potential site was shown in the more detailed project reports). If our idea is accepted the final site selection will be subject to severe financial, legal and administrative constrains. We must mention that our preliminary model runs with a hypothetic wetland indicated that about 3% of total-phosphorus could be retained on the long run, and this could considerably improve the chance of maintaining the presently ecologically diversified state of these water systems, avoiding planktonic or macrophyte hypertrophication. 5

6 Our hydrobiologist team worked also on the development of monitoring methods that could allow the correct assessment of the state of the aquatic environment in such complex and highly diverse water systems like Szigetköz. The result of their work also gives a message to the relevant wetland monitoring guidelines associated with WFD. Namely, that much more detailed monitoring of the vulnerable wetlands are needed in terms of frequency, spatial distribution, quality-constituent and species number if one really wants to protect the last remnants of Europe s once vast floodplain ecosystems. Upgrading of the monitoring of macro-invertebrates, the main markers of the present and near-past state of the ecosystem, is one of the key issues (see the illustrations of our work below): Budapest 4 January 24 Prof. Dr. Géza Jolánkai Scientific adviser, VITUKI team leader 6