- analysis of climate change and river runoff variation;
- research of extreme hydrological phenomena in the context of climate change;
- research of wave, hydrodynamic, and sediment processes in water bodies;
- research of environmental impact of energy and transport objects;
- collection and analysis of data on Lithuanian water bodies (rivers, ponds, the Curonian Lagoon, and the Baltic Sea).
Research objects and tasks
The most significant research objects of the Laboratory are Lithuanian rivers and lakes, the Curonian Lagoon, and the Baltic Sea. The state of these water bodies is determined by extreme natural phenomena, such as storms, floods, and anthropogenic activity (energy production, navigation, and ponds). Therefore, the assessment of the change of state of water bodies is one of the most important research tasks.
Using the information collected in the hydrographic and hydrometeorological database and applying the latest digital modelling methods, the Laboratory solves the following tasks:
- impact assessment of climate change on water bodies;
- analysis of change of extreme hydrological phenomena of water bodies;
- digital modelling of waves, hydrological and hydrodynamic processes, and sediment transport in water bodies;
- environmental impact assessment of anthropogenic activities on water bodies and justification of environmental protection measures;
- environmental impact assessment of new sea ports and ports under construction;
- exploitation of sea harbours and waterways, ensuring the nautical depth;
- modelling of pollution dispersion in water bodies;
- sensitivity and uncertainty analysis of hydrological and hydrodynamic processes.
The Laboratory of Hydrology carries out fundamental and applied research in the environmental engineering field. The basis of the research are numerous hydrographic, hydrologic, morphometric, and meteorological data collected by the Laboratory of Hydrology over the years as well as innovative digital modelling software (MIKE 21 system, developed by the Danish Hydraulic Institute for modelling of wave, hydrodynamic, and sediment transfer processes and pollution dispersion, hydrological process model HBV, developed by Swedish Meteorological and Hydrological Institute, as well as geographical information system). This enables solving the most important environmental tasks by assessing the impact of anthropogenic activity and climate change on the environment and justifying environmental protection measures.
In the past decade, the Laboratory has been carrying out research related to the assessment of the impact of climate change on water resources.
In 2016, a new state funded scientific research project Nemunas Basin rivers’ runoff change and its uncertainties according to scenarios presented in the Intergovernmental Panel on Climate Change Fifth Assessment Repor
t was started (head Dr. J. Kriaučiūnienė).
At present time a climate change issue is often discussed in public. With regard to this, Intergovernmental Panel on Climate Change (IPCC) released five reports, where most of attention is dedicated to thorough findings on climate change. Main objective of the released reports is to familiarize the society with possible climate change outcomes, adaptation measures and outcomes’ mitigation methods. Following IPCC reports as well as scientific society information resources, a detailed analysis of climate change scenarios development and their formation principles was carried out in the project, since in further course of this research the up-to-date RCP (RCP – Representative Concentration Pathways) scenarios, mentioned in IPCC report AR5, will be applied. Analysing the investigations announced by foreign and Lithuanian researchers it was difficult to find a number of publications where RCP scenarios would be used in forecasting runoff, thus this fact extremely emphasizes novelty and relevance of this research. Original runoff forecasting method was developed in the research study, which is guided by selection of global climate models, statistical downscaling methods and preparation of RCP scenarios for hydrological modelling. Hydrological and meteorological database necessary for research was also updated. Hydrological models for the rivers of Neris, Žeimena, Šventoji, Nevėžis, Šušvė and Minija were created, their calibration and validation in accordance to new reference period (1986-2005) was carried out, which due to changed climate conditions is recommended in AR5 report.
Fig. 1. Comparison of simulated and observed discharge of the Neris at Jonava during model validation period (1996-2005)
In 2016, the Laboratory together with other divisions of the Institute continued the long-term institutional research and experimental development (further R&D) program Analysis of usage of renewable resources for efficient energy production and environmental impact. The research objectives of the Laboratory of Hydrology in included:
1) to summarize wave energy research results in the Baltic near-shore (Lithuanian territorial waters);
2) to conduct assessment of small and medium-size rivers (excluding Nemunas and Neris) hydrotechnical resources.
There is a 90 km length Baltic seashore zone, where the wave energy could be applied for extraction. In the period of 2013-2015 wave parameter database was developed, statistical and probabilistic analysis of average wave height parameters was carried out. A wave dispersion model for Baltic near-shore, which belongs to Lithuania, was developed and calibrated using a widely known numerical system MIKE 21, wave parameters under different hydrometeorological conditions were estimated. In 2016, results of all wave and their energy research in the Baltic near-shore (Lithuanian waters) were summarized, also paper Assessment of wave regime and energy resources in the Baltic Sea near-shore (Lithuanian territorial waters)
was submitted for scientific journal “Oceanologia
”. While estimating energy potential of near-shore waves, the characteristics of wave power flux (kW/m), the value of which depends on wave height and period, were chosen. In a year of high wave intensity (1973-1974), the mean wave power flux at 10 m isobaths was 1.75 kW/m, at 20 m isobath – 2.07 kW/m, at 30 m isobath – 2.16 kW/m. In a year of median wave intensity (1994–1995), the mean wave power flux at the mentioned isobaths was 1.10, 1.32 and 1.38 kW/m, and in a year of low wave intensity (1976–1977) – 0.64, 0.77 and 0.80 kW/m, respectively. Modelling results of wave dispersion in accordance with the developed methodology enables to conduct a preliminary assessment of wave energy resources in chosen design years at any Baltic near-shore place. Estimated wave energy resources in Lithuanian territorial waters are not significant, thus in the future it is beneficial to install wave power plants only in those near-shore places, where wind energy will be expanded and relevant energy system infrastructure will be established (Fig.2).
In assessment of hydrokinetic resources of small and medium-size rivers (without Nemunas and Neris) was carried out and article Assessment of hydrokinetic resources of small and medium-size rivers: the Lithuanian case
was submitted for scientific journal "Baltica"
. Research results reveal that basic hydrokinetic energy limiting factors of rivers segments are average river depth and average flow velocity in cross-section, whereas river runoff usage degree depends on rivers’ base runoff. While analysing distribution of the comparative power of river segments in the area, it may be observed that plain relief rivers, river lower reaches and all very small rivers as well as river upper reaches are distinguished for much lower kinetic power. Rivers, running via slopes of the Baltic and Žemaiciai heights have very high inclination, and if compared, are watery due to big amount of precipitation. These rivers are the Šventoji (of the Neris), the Jūra, the Žeimena, and the Merkys. The comparative capacity of these rivers’ segments amount to 50-200 W/m. Meanwhile the Nevėžis, the Nemunėlis, the Mūša, and seacoast rivers are not distinguished for energy value since their segments’ comparative hydrokinetic power is 10-20 W/m. Using geographical information systems (software ArcGIS), Lithuanian small and medium-size river segments (where average depth is more than 0.5 m and average velocity bigger than 0.4 m/s) were selected, their geographical distribution was investigated, classification of river segments was carried out, requirements for protective areas were estimated. Potential of Lithuanian small and medium-size rivers’ hydrokinetic resources is 35.9 thous. kW. Some part of these resources (22.3 thous. kW or 62.1%) is limited by environmental requirements in the protected areas. Thus potential power of Lithuanian small and medium-size rivers is 13.6 thous. kW, which during 8 months may produce 79.7 million kW h of energy.
Fig. 2. a) wave height distribution at Baltic near-shore (Lithuanian territorial waters), at wind blowing with velocity 15 m/s;
b) average wave power flux at near-shore at 10, 20 and 30 m isobaths.
National research program "Agro-, Forest And Aquatic Ecosystem Sustainability" project
"Impact Assessment Of Climate Change And Other Abiotic Environmental Factors On Aquatic Ecosystems"
The main objective of the project is to identify environmental factor changes (water temperature, hydrological regime and water quality elements) and their impact on aquatic ecosystem animal diversity and productivity and to carry out a comprehensive impact assessment in accordance with the multi-year data and climate change scenarios. The period of project implementation is 2015–2018. The first task of the project has been already completed: methods for assessment of climate change impact on the state of aquatic ecosystem were developed. According to the work plan, LEI together with the project partners (Aleksandras Stulginskis University, Vilnius University, and Nature Research Centre) completed the tasks planned for 2016:
- projection of climate indicators change significant for water ecosystems in the 21st century in accordance with different climate models and scenarios output data;
- assessment of regularities and their extremes of abiotic factors (water temperature, river runoff and water quality parameters) variation in accordance with annual data and projection according climate scenarios chosen for river basins and the Curonian Lagoon;
- assessment of impact of abiotic factors extremes on the diversity of water ecosystem fauna and productivity in the chosen river basins and the Curonian Lagoon.
On January 15 and October 7, 2016 two seminars for project participants took place at Lithuanian Energy Institute, where results and work plans were discussed. On 26 October, Professor Lars Rudstam from Kornel University, USA (Fig.3) participated at the seminar and shared his experience and ideas.
Fig.3. Moments of meeting with Professor Lars Rudstam
European Network of Freshwater Research Organisations, www.euraqua.org
In 2008, LEI Laboratory of Hydrology joined the EurAqua organization, which consists of the most influential scientific institutions of 24 European countries, conducting research of water resources. EurAqua has the following main objectives:
- To participate in the formation of water research policy in the European Union;
- To formulate and propose the most significant and actual themes on water resource research, which could be included into Horizon 2020 calls for projects;
- To form consortiums of the EurAqua scientific institutions by preparing joint proposals for Horizon 2020 projects;
- To prepare scientific articles and technical reviews on problematic areas in European water resource research;
- To organize conferences on pertinent topics (the impact of climate change on water resources, flood analysis and forecast in Europe, etc.).
On April 7-8, 2016, the 46th meeting of EurAqua members took place in Zagreb University (Croatia). Main European water policy issues were discussed at the meeting: climate scenarios in the future, implementation of Joint water Directive in the background of climate change, uncertainties analysis in forecasting water resources’ change. Topics of Horizon 2020 projects as well as possible research groups from EurAqua institutions were discussed.
Cooperation with scientific institutions
The Laboratory of Hydrology closely cooperates with the Institute of Environmental Engineering of the Kaunas University of Technology and has been publishing a scientific journal Environmental Research, Engineering and Management since 1995. The researchers carry out complex environmental investigations together with the scientists of Nature Research Centre, Vilnius University and Aleksandras Stulginskis University.
Aiming at the development of up-to-date infrastructure for the common needs of scientific research and technological development of the Lithuanian sea sector, the Laboratory of Hydrology began contributing to the activity of the association Baltijos slėnis (the Baltic Valley). One of the main objectives of the Integrated Science, Studies, and Business Centre regarding Lithuanian sea sector development is to unite institutions and departments of maritime science. The initiators of the establishment of the Valley are Klaipėda University, Nature Research Centre, Lithuanian University of Health Sciences, Lithuanian Energy Institute, and maritime business companies. Two directions of scientific research and experimental development are planned: sea environment and maritime technologies. The partners of the Baltic Valley (Klaipėda University, Nature Research Centre, Lithuanian Energy Institute, PE Space Science and Technology Institute, and State Scientific Research Institute Center for Physical Sciences and Technology) bring together their experience, professional knowledge, capacities and business reputation, and human, labour and technical resources to participate in the implementation of the 2007–2013 Human Resource development operational program of priority 3: Strengthening the capacities of researcher means VP1-3.1-ÐMM-08-K Implementation of research and development activities under the national complex program topics of the project Development of Lithuanian marine sector technologies and environmental research (2013–2015). Researchers of the Laboratory together with Klaipėda University researchers actively participated in the activity of the subtopic Simulation of Hydrodynamic and Lithodynamic Processes in the Baltic Sea Near-shore.
Major applied works of the laboratory
The Laboratory carries out applied research work on the environment and prepares hydrotechnical construction projects following agreements with enterprises and organizations:
- Under the agreement with JSC Sweco Lietuva, the study Assessment of hydrodynamic conditions and sediments balance variations of general plan of Klaipėda state seaport (land, internal water area, external roadstead and related infrastructure) was prepared.
- Under the agreement with the Nature Research Center, the Assessment of the impact of water level fluctuation on fish and water bird population in Kaunas hydro power plant reservoir was carried out.
- Under the agreement with JSC Sweco Lietuva, project Reconstruction of Klaipėda state seaport northern and southern piers as well as preparation of design proposals for partial Curonian Spit slope consolidation is being prepared.
- Under the agreement with SC Lietuvos energijos gamyba project Update and adjustment of Kaunas hydro power plant reservoir usage and surveillance regulations was carried out.
MIKE 21 model system was applied for the development projects of Klaipėda Seaport in estimating their impact on the environment and navigation conditions. For improvement of navigational conditions of Klaipėda port waters and dredging of the port fairway from 14.5 to 17 m, it is necessary to choose environmental protection measures that could be used to avoid negative consequences for the ecosystem of the Curonian Lagoon.
In 2016, researchers of LEI Laboratory of Hydrology under the agreement with JSC Sweco Lietuva participated in preparing the general plan for Klaipėda State Seaport. While investigating hydrodynamic and sediment changes of the Klaipėda Strait and the Curonian Lagoon due to expansion of the Klaipėda seaport the following alternatives are to be investigated:
- alternative “0” – the present situation (bathymetric condition of seaport water area in 2015);
- alternative 1 (reconstruction of seaport gates southern pier, channel depth of harbour entrance – 17.5 m, channel depth of navigation – 17 m and width – 200 m, construction of seaport southern gates);
- alternative 2 (dredging of port area in accordance with alternative 1, development of southern seaport part behind the Kiaulės Nugara island);
- alternative 3 ( dredging of port area in accordance with alternative 1, construction and expansion of northern port part in the Baltic sea);
- alternative 4 (port expansion in accordance with alternatives 1, 2, and 3).
Expansion of Klaipėda seaport (installation of fairway in new dimensions and reconstruction of harbour gates) changes flow rates and structure. With increased depths in the port area sediment transport and accumulation conditions as well as wave regime change (Fig.4). While implementing Klaipėda expansion alternatives 1 and 3, permeability of the Klaipėda straight increases by 2.5-3%, if compared to alternative “0”. Meanwhile alternatives 2 and 4 do not change the water balance of the straight (permeability changes 0-0.5%). Applied engineering solutions (southern gates, filling in of? eastern channel, the old gates remained head of seaport, expansion of seaport into the Baltic Sea) are considered as favourable to environment objects, which maximally reduce the impact of seaport expansion on the environment.
Fig. 4. Klaipėda straight flow structure for „0“ (a) and 4 (b) alternatives,
when a discharge of 2700 m3/s flows from the Curonian Lagoon to the Baltic Sea