Environmental impacts of the Gabcikovo Barrage System to the Szigetköz region

Abstract

In order to commission a large hydroelectric power plant in 1992, the Republic of Slovakia diverted the Danube River with a dam at a common section between Hungary and Slovakia. The dam is located at Gabcikovo in what now is Slovakian territory. The diversion, known as the Gabcikovo Barrage System (GBS), subsequently impacted one of the most ecologically important and unique alluvial floodplains of the Danube Basin. This, in turn, affected the hydrological regime of the Danube downstream and so, potentially, water supplies and water quality for millions of people. The potential environmental impacts of the diversion to the floodplain and downstream were not thoroughly studied prior to construction of the dam. The project was originally started jointly between Hungary and Slovakia in 1977 and conflicts arose between the two countries resulting in a case before The International Court of Justice (IJC) in 1993. In 1997, the IJC rendered a decision that a compromise solution had to be worked out accommodating the needs of both Hungary and Slovakia. The IJC said, in essence, that the dam would remain in place, but must be modified so as to minimize environmental impact. This paper reviews the history of the project and describes some impacts of the river diversion that may be attributed to changes in the water regime. In order to assess environmental impacts to the region due to diversion of water from the natural channel of the Danube, this study assessed, using satellite imagery, land cover change between 1988 and 1997. This study also correlated the satellite-derived data with reports from the Hungarian Ministries of Agriculture and the Environment and the North-Transdanubian Environmental Inspectorate. The analysis determined that, although land cover change occurred in the region during this period, not all of the changes could, necessarily, be related to the hydroelectric facility. The results of the analysis show that: (i) there were land cover changes in the study period within the study area; (ii) more time is needed in order to establish a link between the hydroelectric facility and environmental changes; (iii) satellite imagery could provide useful information in studies of this type, but the imagery must be used in conjunction with ground observations. This paper represents the views and opinions of the authors and not necessarily those of either the National Science Foundation or the Hungarian Academy of Sciences.