Aquatic environmental assessment of Lake Balaton in the light of physical-chemical water parameters

Abstract

One of the issues of the Hungarian Water Management Strategy is the improvement and upgrading of the water of Lake Balaton. The Water Framework Directive (WFD) specifies and sets forth the achievement of the good ecological status. However, the assessment of the water quality of the lake as a complex system requires a comprehensive monitoring and evaluation procedure. Measurements were carried out around the Lake Balaton at ten different locations/sites and 13 physical-chemical parameters were monitored at each measurement site.For the interpretation of the water chemistry parameters the Aquatic Environmental Assessment (AEA) method devised by authors was used for the water body of the Lake Balaton. The AEA method can be used for all types of the water bodies since it is flexible and using individual weighting procedure for the water chemistry parameters comprehensive information can be obtain. The AEA method was compared with existing EIA methods according to a predefined criterion system and proved to be the most suitable tool for evaluating the environmental impacts in our study.On the basis of the results it can be concluded that the status of the quality of studied area on the Lake Balaton can be categorized as proper quality (from the outcome of the ten measurement sites this conclusion was reached at seven sites).

Does the Kis-Balaton Water Protection System (KBWPS) Effectively Safeguard Lake Balaton from Toxic Cyanobacterial Blooms?

“…During June 2018, most of the water parameters observed in Lake Balaton were within proposed guideline limits. These results coincide with the results of Sebestyén et al [ 41 ]. Values of pH, conductivity, dissolved oxygen and oxygen saturation are near the guideline values specified by the Hungarian Government Decree [ 36 ].…”

“…At this timepoint, the internal load of the lake and diffuse pollution from sewage effluents and agricultural areas have a more pronounced effect on the trophic status of the lake. This is corroborated by the study of Sebestyen et al [ 41 ] which demonstrates that the inner basins (predominantly Basins 2 and 3) have a higher total phosphorus, Ortho-P and nitrate concentrations than Basin 1. However, this does not take away from the importance of the KBWPS, as it considerably reduces the nutrient load flowing in from the Zala River.…”

“…Levels of nitrates, nitrites and orthophosphates for Lake Balaton are difficult to discuss as the guideline levels are below our detection levels. However, the study of Sebestyén et al [ 41 ] does indicate that all of these nutrients are in higher concentrations than the proposed guidelines, and that Lake Balaton is primarily contaminated with higher nitrate, Ortho-P and total phosphate levels. Interestingly, the highest concentrations of these nutrients were observed in Basins 2 and 3, and not in Basin 1 as would be expected, indicating that the Zala River is not the main contributor to these high values as in previous decades [ 17 , 41 ], and that they could be the result of diffuse pollution from the surrounding agricultural areas and wastewater, or of the internal load of the lake.…”

Network-Based Topological Exploration of the Impact of Pollution Sources on Surface Water Bodies

“…With regard to lakes and wetlands, 9,123 registered elements can be identified in Hungary with a total area of 2,100 km 2 , of which 188 water bodies with a cumulated water surface of 1,190 km 2 were formed after the mergers. An interesting hydrogeographical feature is that Lake Balaton-the largest natural shallow lake in Central Europe-alone accounts for 596 km 2 (Sebestyén et al, 2017). In this analysis, 188 stagnant water bodies are examined in detail based on the data available on the water management map (General Directorate for Water Management, 2015).…”

Informative Environment Qualifying Index

“…The following environmental elements were taken into consideration: Some EIA techniques, which were developed for the analyses of specific environmental elements, e.g. Németh et al provided a quantitative tool for bodies of surface water [23] to show changes in water quality of Lake Balaton, the largest natural shallow lake in Central Europe [24,25]. In the case of air pollution, the Air Quality Index (AQI) is a useful tool to improve public understanding and participation [26].…”