Field of Study – Physical Geography (N 006)

Deadlines for main admission procedures to doctoral studies:

	Doctoral Admission Procedure	Deadlines
1.	Submission of applications and admission documents for applicant who have obtained a master’s degree from a Lithuanian higher education institution	April 7, 2026 – June 19, 2026 (until 12:00 p.m.)
1.	Submission of applications and admission documents for applicants who have obtained a master’s degree from a foreign higher education institution and who do not have a document confirming the recognition of their diploma in Lithuania	April 7, 2026 – May 18, 2026 (until 12:00 p.m.)
2.	Motivational interview with the admissions commission	July 1, 2026 (10:00 a.m.), at Conference hall, there will be an option to participate remotely
3.	Information about the preliminary results	July 3, 2026 (from 2:00 p.m.)
4.	Submission of appeals regarding preliminary admission results	Until July 7, 2026 at 10:00 a.m.
5.	Information about the final results	July 9, 2026 at 3:00 p.m.
6.	Conclusion of doctoral study agreements	July 13 – 17, 2026 (until 3:00 p.m.)

Selection Criteria for Admission to Doctoral Studies in 2026

Field of science, code	Physical Geography, N 006
Selection procedure	Motivational interview*
Structure of the competition points and their coefficients
Weighted average of Diploma Supplement grades (WA)**, up to 10 points	Motivational interview assessment (I), up to 10 points	Evaluation of scientific experience and scientific works (SW), up to 10 points
0,3 x (WA)	0,5 x (I)	0,2 x (SW)
Minimum score	7,5

*The interview will focus on the chosen dissertation topic. The interview will be evaluated based on the applicant’s research competence, motivation in selecting the dissertation topic, theoretical background, and initial methodological skills. The presentation should be no longer than 10 minutes (PowerPoint presentation).

**Weighted average of Diploma Supplement grades (40%) and evaluation of the final master’s thesis (60%).

Climate change, intensive agriculture, and dense drainage networks increase nutrient leaching from agricultural catchments and intensify lake eutrophication processes. More frequent extreme precipitation, warmer winters, and longer frost-free periods enhance nitrogen and phosphorus runoff into surface waters, particularly in drained catchments with dense drainage systems and insufficient buffer strips. These conditions lead to short-term but intense nutrient fluxes that can constitute a significant share of the annual load and trigger phytoplankton blooms even in lakes of relatively good ecological status. Lakes are particularly sensitive to such changes due to slow water renewal and long-term nutrient accumulation.

In Lithuania, diffuse pollution from agriculture is one of the main drivers of deteriorating ecological status of water bodies. A large proportion of the country is drained, and straightened river channels together with dense subsurface drainage networks accelerate water transport and, consequently, nutrient delivery to lakes. The interaction between climate change and drainage systems may further amplify these processes, highlighting the need to assess their combined effects. Studies indicate that reducing nutrient inputs is more effective for improving lake water quality than in-lake management measures, emphasizing the importance of analysing factors controlling nutrient export from agricultural areas.

The aim of this study is to assess the combined effects of climate change, drainage systems, and agricultural activities on nutrient loads and lake ecological status using hydrological and ecosystem modelling. The catchments of the Dzūkija lakes Dusia, Metelys, and Obelija—characterized by substantial agricultural land use and developed drainage networks—will be analysed. The SWAT model will be applied to simulate hydrology and nutrient transport, while the AQUATOX model will be used to evaluate lake ecosystem responses, in order to determine the joint influence of climate change, drainage density, and agricultural intensity on lake eutrophication and ecological status changes.

The karst region of Northern Lithuania covers about 1935 km², of which ~300 km² is an intense karst zone with sinkholes and karst lakes. The region is characterized by its unique specificity, which is determined by its unique geological conditions, minimal groundwater protection, and rapid interaction between precipitation, surface water, and groundwater.

The region is extremely sensitive to anthropogenic activity and climate change – both can accelerate the water circulation in the Tatula suite gypsum (precipitation – water infiltration – gypsum dissolution – river runoff), lead to the formation of underground voids and the emergence of sinkholes that are difficult to predict. These processes depend on the geological structure, water circulation, and man activity, but in recent years the intensity of karst processes has been particularly affected by climate change.

Warmer winters shorten the seasonal frost period, increasing precipitation and decreasing snow accumulation promote faster water circulation in gypsum rocks, forming underground cracks, voids and new sinkholes. This poses a threat to human safety, infrastructure and worsens water quality. Karst landscapes transform runoff: increase infiltration, reduce floods, change the shape of the hydrograph.

For this study measurements of river runoff in the intensive karst zone and surrounding areas will be collected and the impact of intensive karst zone on runoff and gypsum chemical denudation intensity during the hydrological observation period will be analysed. Based on IPCC scenarios that include changes in the water cycle, the runoff of the karst region and the intensity of gypsum chemical denudation will be predicted until 2100.

Long-term measurement data of gypsum denudation products in the karst region of Northern Lithuania will also be collected and systematized. Based on them, the intensity of gypsum chemical denudation will be calculated and the impact of climate change on gypsum chemical denudation will be assessed.

Research results will help assess the impact of the active karst zone and climate change on runoff and gypsum chemical denudation, when applying sustainable management of the karst region.