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Sustainable Development and Technologies National Programme of the Hungarian Academy of Sciences


Designing a sustainable water level management of lake Balaton

Lake Balaton has been a regulated lake for over 150 years. Regulation tries to reduce the meteorologically driven level fluctuations of this large, shallow lake to an ever narrower range. This effort has been successful for decades by regulating only the drainage, due to the lake’s positive natural water balance.

However, it is expected that climate change will have a negative impact on the sustainability of the current water level management regime. This is due to the gradual disappearance of the natural water balance surplus until the end of the century. The lake is especially susceptible to changes in water levels caused by climatic fluctuations over the years, as it is shallow and has substantial infrastructure built for a stable water level.

The effect of climate change on the water balance of Lake Balaton has been a topic of concern since the drought of 2000-2003 and the subsequent decrease in water levels. Prior to the algal bloom in 2019, experts and the public alike viewed this issue as the most significant threat in the near future.

According to the water balance report from the local water authority, there were no years with a negative natural balance between 1921 and 1999, meaning that the water level of the lake did not decrease annually without any draining. However, since 2000, such years have occurred regularly. As a result, the control level was raised to conserve water for drier years. However, studies investigating the causes of the 2019 algal bloom have shown that high water levels can promote the persistence of thermal stratification. This, in turn, can lead to the development of large algal biomass due to the amplification of internal nutrient loads. This statement adds complexity to the issue of regulating water levels. The potential negative impacts of high water levels on water quality and riparian vegetation make it clear that a long-term solution cannot involve simply increasing the amount of water stored in the lake. Therefore, sustainable management must find a compromise between the competing priorities of water resources and water quality as climate change continues.

Water level regulation is not solely a geoscience or engineering issue. It is also crucial to meet the needs of water users and maintain the ecosystem services expected by them, given the intensity of lake use and its national and international significance. Furthermore, the needs of water users are evolving, partly due to past regulation and partly due to independent processes. The reaction to the drop in water levels during the 2000-2003 drought demonstrated that a change in the regulation regime is highly likely after significant dissatisfaction with water levels. Therefore, for water level regulation to be sustainable, it must align with current societal needs as well as scientific sustainability.

The basic research question is: “How can the water level of Lake Balaton be regulated in a sustainable way until 2060?”

Conflicts of interest often arise between climate-responsive water resource management, ecological needs, and the needs of water users. These conflicts cannot always be resolved based solely on scientific evidence. Therefore, the aim of this research is to develop a decision support system that can assist policy actors in designing a sustainable water stress management regime for a given period.

Riverine transport of macroplastics and their potential recycling

The increasing plastic pollution of our waters is a serious environmental, social and economic problem at the same time. Although the problem is already well known, in order to develop proper interventions, it is necessary to understand the processes taking place in nature and the possibilities of recycling.

A more precise understanding of the riverine transport of plastics helps to explore the environmental impact of plastics, and contributes to mitigating the environmental impact and developing appropriate intervention methods. The latter is particularly important from the point of view that rivers act as conveyor in the transport of plastic, that finally ends up in the receiving lakes, seas and oceans burdened with the pollution. Therefore, in order to reduce this burden, it is necessary to intervene at the source and during the transport processes in the rivers. On the topic of macroplastics, significant Hungarian-initiated studies are underway, primarily focusing on our Eastern rivers (Tisza River basin), where the presence of plastics causes an extraordinary problem, although these related projects are more likely to deal with the plastic problem itself on site in form of civil actions.

On the other hand, in the present research work, we try to explore the transport processes in rivers with different methods, and to understand the roles of hydrological, morphological, vegetation cover and other characteristics of rivers, supplementing all this with qualitative and quantitative analytical tests of the plastic waste samples from the rivers. Recently, significant steps have also been taken in the field of recycling used plastic, the further development of which may open new paths in plastic-based product development.

The planned research is based on two pillars. On the one hand, we explore the dynamics of the transport of plastics in watercourses with the aim to understand the environmental effects of pollution and to be able to plan and implement in a well-founded way their targeted reduction in the future. In the research, we investigate the riverine transport of macroplastics larger than 5 mm in order to better understand the typical sources of pollution, their transport characteristics and trapping locations, and the spatio-temporal dynamics of the transport processes. We use new developments, intelligent video-based measurement procedures for the study, and carry out extensive field sampling together with hydrological measurements in the selected areas. We perform simulations with parameterized and verified computer models based on field data. Another pillar of the research is the lab analysis of the plastics found in the river and the assessment of their reuse possibilities. On the one hand, FT-IR and Raman spectrometry are used to determine the quantitative and qualitative composition of polymers from representative sampling, as well as the degree of degradation of polymers due to environmental effects. Accelerated aging tests are used to model and compare the degradation of traditional and biodegradable plastics as potential substitutes, with particular attention to the size and amount of microplastics produced during degradation. Building on a recent development, we are further developing new uses for plastic waste.

The project is implemented in cooperation with the Plastic Cup citizen initiative.

Riverine sediment management

Rivers play a crucial role in our lives, socially, economically and environmentally. Their water resources are exploited in many areas, e.g. for drinking water, irrigation, cooling power plants, navigation, recreation, etc., and their conservation and improvement is therefore a key issue. However, as a result of human interventions (e.g. regulation, extraction of sediment, construction of dams, climate change), the water balance of our rivers has changed and, as recent studies have shown (e.g. DanubeSediment Interreg DTP project), the longitudinal and temporal characteristics of the sediment transported by water have also changed significantly. The upheaval of the sediment budget of our rivers has caused the so-called free-flowing sections (i.e. not dammed areas) to deepen, e.g. the Danube bed in our country has subsided by almost two meters on average over the last 60 years, but similar trends can be observed in other rivers. The deepening of the riverbed has negative effects in many areas, such as lowering the groundwater level, deteriorating navigability, habitat degradation and even rising flood levels. In order to stop these negative processes, in addition to water management, the management of sediment must also play an important role, since the lack of sediment or even excess sediment is the root cause of these problems. The main mission of the planned project is to provide the scientific basis for a strategy for the management of water resources, which will have to be developed in the future by the domestic water sector. Our investigations will be based on two pillars. On the one hand, measurements and data analyses will be carried out with the aim of gaining a better understanding of the deformation processes of our major domestic rivers (Danube, Tisza, Drava), because the fundamental question is whether the adverse bed subsidence mentioned above is still in progress or whether our rivers have already reached their new equilibrium state as a result of the interventions. The second pillar is the development of modelling techniques that can predict the morphological evolution of rivers and provide an appropriate basis for planning restoration interventions.

Sustainable water resources management

Our studies on sustainable water resources management are based on two pillars. First, by improving evaporation estimation methods using routine meteorological data, we expect to obtain a more accurate picture of the temporal and spatial distribution of evaporation. Then we continue with the analysis of land use in influencing the microclimate of the region and the impact of the amount and distribution of evaporation.

Data analyses will be carried out to better understand what is needed to maintain the climatic equilibrium of a landscape. Over the past centuries, human interventions (increasing ratio of built-up areas, intensive agriculture, river regulation, flood control, etc.) have significantly altered the landscape surface throughout the developed world. As a small part of evaporation occurs directly from the surface and the larger part through vegetation (transpiration, which also ensures the functioning of the ‘small water cycle’), we also want to analyse the conditions for the replenishment and continuous re-production of water resources.

Depending on the available data, an attempt will be made to quantify the impacts of different types of land use as well as to estimate long-term changes in climatic water demand. Our studies will be coordinated with sub-projects of the National Laboratory for Water Science and Water Security (VVNL), allowing for horizontal linking with other scientific disciplines. The coupled research will provide the basis for the development of a unified model of the climatic energy distribution system, including both the hydrological and atmospheric cycles and their relationship to the surface cover. Based on the theoretical results, we aim to promote the spread of an integrated approach to water and to propose practical applications of a combined hydrological cycle and sustainable water resource management model.

Sustainable cities: ecological and human aspects of urban biodiversity

Introduction and problem statement

Today, more than half of the world’s population lives in cities, and this proportion is steadily increasing. Understanding how urban ecosystems function is essential to maintaining and improving urban quality of life and well-being. For city dwellers, these ecosystems are their daily, direct link with the living world and nature. The remaining urban natural habitats, waterfront corridors, small ponds, abandoned areas, managed parks, private gardens, balconies, and roof gardens are essential elements of the urban ecosystem. There is significant biodiversity associated with these habitats. In field studies and meta-analyses, the researchers of this project have found that species numbers of many groups of organisms decline significantly with urbanisation, particularly in the city centres, and that the urbanisation gradient significantly impacts animal behaviour. Urban habitats provide essential ecosystem services such as soil, water and air quality protection and climate regulation. High human population densities raise several water quality and water management issues related to increased water use (e.g. micropollutants, sewer smell).

Cities are home to complex community dynamics between humans and a wide range of living organisms, and urban reservoir hosts, vectors and pathogens pose an increased epidemiological threat to the human population living in cities. The high population density and the central commercial and transport role of cities facilitate the introduction of pathogens and vectors from remote areas and the rapid emergence of human-to-human infections. The heat island effect, especially combined with climate change, helps pathogens, their vectors and reservoir hosts to survive the winter months more easily.

In maintaining green and blue infrastructure and associated biodiversity in cities, the functional connections between habitats are crucial. In cities with well-connected green and blue infrastructure, the impact of urbanisation can be significantly reduced. A key question for this research is how methods developed for the restoration of natural habitats can be adapted to urban environments.

The aim of the research programme

The programme will examine the functioning of urban ecosystems, their human aspects and the interventions needed to maintain and restore their functioning within a coherent framework of three interrelated themes.

1. Exploring the biodiversity of urban habitats and understanding the functioning of urban ecosystems.
Our multi-taxon studies aim to explore the mechanisms that influence the biodiversity and ecosystem services of urban terrestrial and aquatic habitats.

Key research topics:
1.1 Multi-taxon analysis of biodiversity along an urban – suburban – rural gradient.
1.2 Pollinators in cities, biodiversity of flower strips and flower beds, factors influencing the composition and functioning of urban pollinator communities.
1.3 Mapping the biodiversity potential of urban ponds at national level and exploring the factors influencing the plant, animal and microbial communities in ponds.
1.4 Understanding the ecological strategies, conditions, and consequences of adaptation to urban lifestyles, through comparative analysis of the characteristics and behaviour of urban and rural populations.

2. Exploring the links between urban ecosystems and city residents and the human aspects of urban ecosystems.
Cities are home to complex community dynamics between humans and a wide range of living organisms, and human activity fundamentally impacts urban ecosystems. Our research aims to explore the diverse relationships and interactions between humans and urban ecosystems.

Key research topics:
2.1 Urban water supply, water quality, composition, functioning and metabolism in aquatic ecosystems.
2.2 Epidemiology of urban green spaces in relation to the risk of infection by mosquito- and tick-borne pathogens.
2.3 Investigating the human and animal health aspects of urban habitats by analysing national-level datasets collected in citizen science programmes.
2.4 Human-wildlife conflict in the built environment: road ecology studies.
2.5 Improving the quality of food crops for cultivation through the supplementation of deficiency elements.

3. Management and restoration of urban habitats, solutions to maintain and enhance biodiversity and functions of urban ecosystems.
Increasing the size and biodiversity of urban green spaces is a key objective of the EU Biodiversity Strategy. Our research examines how habitat restoration methods and nature-based solutions developed in natural areas can be applied in urban environments.

Key research topics:
3.1 Perspectives for urban green and blue infrastructure development; providing science-based guidance through developing evidence-based management plans.
3.2 Assessing the restoration potential of urban green infrastructure; cost-effectiveness analysis of restoration methods.
3.3 Explore the multi-taxon biodiversity associated with gardens and use the results to produce a science-based practical guide to designing nature-friendly gardens.

The research programme is closely linked to the UN Sustainable Development Goals ‘Good Health and Well-being’, ‘Clean Water and Sanitation’, ‘Sustainable Cities and Communities’, ‘Life on Land’. The results of our research can be integrated into urban green and blue infrastructure planning and urban design strategies.

Development and mapping of a soil hydrophysical categorization system for the support of hydrological modelling

The soil hydraulic properties (such as water retention and hydraulic conductivity associated with soil pore size distribution) determine how much of the precipitation or irrigation water reaching the surface is capable to infiltrate into the soil, how much becomes runoff, and how much and how long time moisture can be stored in the soil. These fundamentally determine hydrological and biogeochemical processes occurring in the soil. Hydrological monitoring and occasional measurement of soil physical and chemical properties of a case study greatly contribute to refining the input parameters of hydrological models and validating estimation procedures.

The implementation of the planned research tasks is grounded by research projects conducted at the institute, focusing on the estimation and mapping of soil hydrological properties (KH124765, WaterJPI – iAqueduct, H2020 – OPTAIN, K48302, K119475, K134563, OTKA 101065, OTKA 131792), the results of which are particularly important in the context of climate change.

During the research, our aim is to renew the soil water management categories of Hungarian soils defined by Várallyay based on statistical analyses, building upon the results of the BO/00088/18 Bolyai Research Fellowship. This involves further development and mapping of the established soil groups complemented with expert rules. We plan to create a soil hydrophysical classification system that describes soil profiles with typical hydro-physical properties found in Hungary and ensures the data requirements for soil hydrological input in models considering soil water management. The created classification system will be supported by measurements examining the soil-plant-water system in a case study.
We are expanding the Hungarian Detailed Soil Hydrophysical Database, called MARTHA with general soil profiles and additional soil hydrological data. We investigate how the application of a model considering dual porosity refines the description of the soil water retention curve. Based on the hydrophysical data of the expanded database’s soil profiles, we define the soil water management groups using statistical methods and experts based rules. The relationship between soil water management groups and easily accessible soil properties is examined using data mining methods, and then the procedure is applied to map soil hydrological groups. The case study data are also utilized as validation points.

Through the planned investigations, we quantify how accurately the description of soil water retention can be refined for soils of different physical and soil types using models that consider both micro and macroporosity. The creation and mapping of soil hydrological groups provide crucial information for designing hydrological response units in watershed-level hydrological models. The formation of soil hydrological groups serves as important input data for national and regional analyses and planning related to soil hydrological properties, providing a comprehensive overview of soil water management characteristics.

The map of soil hydrological groups, along with soil moisture monitoring data, supports sustainable agricultural and water management planning.

Systematic analyses of soil use and greenhouse gas and ammonia emission and evaluating of their linkages

To understand the sources and sinks of greenhouse gases (GHGs – as carbon dioxide, nitrous oxide) and ammonia (NH3), the changes and the possibilities in reduction in their concentration is one of the main goals of recent scientific researches. Greenhouse gases have long atmospheric lifetime therefore they can easily mix up in the atmosphere having global not only regional effect. In comparison, NH3 has a more regional impact. The increasing atmospheric concentration of GHGs and also the increasing NH3 emission from agricultural activities is a global issue due to climate change and environmental – and human health risks. The amount and type of the fertilizer and the tillage method applied during agricultural production can highly influence the rate of emissions. Good agricultural practices keep in consideration the emission reduction possibilities. Between 2005 and 2018 emissions from agricultural origins decreased less, which means the sectoral regulations do not help in emission reduction. Further potentials must be found and applied to reduce agricultural emissions. We must find and evaluate agrotechnical and agronomic possibilities to reduce emissions and increase carbon sequestration. We cannot achieve either the NH3 emission reduction targets without more efficient fertilizer usage and without measuring and study the effect of environmental and soil physical-chemical and biological impact on NH3 emission. The project aim is to study the effect of soil physical, chemical and biological parameters on the emission of the given gases in laboratory and field experiments. We study the elements of the C-N turnover under different soil nutrient supply and different soil status with C3 and C4 plant species. We evaluate the relationship between soil nutrient supply, plant growth, plant biology, functional diversity of rhizosphere microorganisms and soil emissions. We also plan to develop the methodology of gas emission measurements with calibration measurements and parallel usage of different analyzers. We build a database from the measured and calculated data. In the framework of the project, we cooperate with the Department of Optics and Quantum Electronics of the University of Szeged. The research is in line with the objectives of the Soil Protection Strategy and the National Air Pollution Reduction Program. The results will contribute to the development and decision support of technologies that optimize soil use, support soil health and sustainable practices.

Innovative Methods for Sustainable Use of Natural Resources

Ensuring a sufficient supply of raw materials, energy and water in sufficient quantity and quality is one of the biggest challenges of our time. Reducing dependence on raw materials and energy is a high priority for our country and the world. Therefore, any development that makes progress in the sustainable use of natural resources and in reducing dependency is important. The targeted research programme aims to carry out research in four priority areas with the following hypotheses:

  • Long-term hydrological data series can provide much more information than is currently available from conventional methods. By developing new interpretation methods, we can gain a much more accurate picture of current and potential future changes in the elements of the earth’s hydrological cycle, including our groundwater resources.
  • The application of artificial intelligence-based methods could open up new opportunities for hydrogeophysical method development, with direct applications in water research and geothermal energy.
  • The storage of hydrogen as a renewable energy source in a safe and efficient manner in the subsurface can be addressed.
  • In addition to primary mining deposits, mining and industrial by-products and electronic waste can be an excellent source, in line with the principles of the circular economy.

Effect of Invasive Species and Human Land-Use on The Ecosystem of Lake Balaton and Its Catchment Area

The spreading of invasive species causes serious problems in native ecosystems worldwide, and unfortunately also in Lake Balaton and its catchment area. In the last 100-150 years, several non-native species have been introduced and immigrated spontaneously into the area Lake Balaton, some of which have established abundant populations and significantly affect the functioning of the ecosystem and the living conditions of native species. The intense human presence and land-use – e.g., residential and recreational areas, agriculture and fish farming – also has a serious impact on the ecosystem of the lake and its surroundings. Further consequence of human activities includes releasing of polluting substances into the environment, which can enter and impact natural areas as well.

The value of Lake Balaton and its surrounding landscape for us is basically based on the “ecosystem services” provided by the natural environment, for example, the beauty of the landscape, the possibility of bathing and sailing in a clean lake water, the excitement of fishing, a clean water base, the natural removal of pollutants and shaping of the microclimate. The availability of all these attractive values depends on the status of the ecosystem.

In this project, we therefore aim to investigate the distribution and ecological effects of invasive aquatic organisms in Lake Balaton and its catchment area, as well as the drivers and possible counter actions of invasions. We also examine how the different land-use activities influence biodiversity, ecosystem functioning and stability, and “ecosystem services” provided by Lake Balaton.


Specific objectives of the project

  • Exploration of the causes of occasional algal blooms and drivers of the primary production: assessment of the composition of the phytoplankton and phytobenthos in Lake Balaton using microscopic and molecular biological methods; examination of factors affecting the nutrient turnover of planktonic and benthic primary production; exploration of factors promoting the mass production of algae; analysis of physical and chemical characteristics of the sediment; examination of organic carbon content and “respiration” of the sediment; assessment of phosphorus turnover of the sediment; evaluation of the role of sediment-dwelling algae on the nutrient turnover. The role of allochthonous organic matter in the nutrient cycle of Lake Balaton: investigation of the bioavailability of organic carbon and the role of the UV radiation using mesocosm experiments.
  • Distribution and competitive advantage of invasive mussel species: assessment of the abundance and biomass of Dreissena species and analysis of their long-term patterns in Lake Balaton; examination of intraspecific and interspecific competition of Dreissena species under different environmental conditions in field and laboratory experiments; laboratory testing of the performance of Dreissena species under different sediment types and extreme environmental conditions (hypoxia, high temperature); assessment of post-mortem nutrient release of Dreissena species.
  • The effect of land-use on the composition, diversity and functioning of macroscopic invertebrate communities: comparison of the functional structure of macroscopic invertebrate assemblages between natural reed, and artificial riprap and harbour habitats in Lake Balaton; taxonomical and functional analysis of invertebrate assemblages of natural, urban and fishpond effected stream sections in the catchment area; analysis of the relationship between human impact (land-use) and functional diversity.
  • The impact of land-use and invasive fish species on the organization and functioning of fish communities: investigation of the assemblage structure of fish communities, habitat use of alien and native fish species in Lake Balaton, Kis-Balaton and streams in the catchment area; examination of the trophic organization of the fish community of Lake Balaton using stable isotopes; investigation of the feeding ecology of the invasive black bullhead by laboratory experiments; population genetic analysis of invasive littoral fish species (pumpkinseed sunfish, monkey goby) in Lake Balaton.
  • Effect of the urban areas on the distribution, morphology and health status of the dice snake.
  • Habitat use, food and health status of the otter in the catchment area of Lake Balaton: mapping the current occurrence, analysis of the long-term distribution pattern and the effect of human land-use, habitat classification; food analysis from faeces, using DNA and stable isotope-based techniques – investigation of the role of non-native/invasive species in the diet; post mortem ecotoxicological and health studies.
  • Spatial and temporal assessment of anthropogenic chemical pollutants (e.g. drug residues, UV filtering compounds) in Lake Balaton and its catchment area.
  • Investigation of the effect of anthropogenic chemical factors occurring in the drainage area of Lake Balaton on aquatic invertebrate test organisms: identification of individual, cellular and molecular level effects on aquatic organisms; examination of the accumulation of active substances; identification of new marker molecules that indicate stress effects in invertebrates; modelling the ecological effects of UV filter compounds from sunscreens on aquatic organisms in mesocosm experimental systems.
  • Long-term analysis of the ecosystem services and their anthropogenic and environmental drivers in Lake Balaton.