Serhii Nazarenko “Patterns of low flow and hydrological drought risk assessment in Lithuanian rivers under climate change” doctoral dissertation defense

Author, Institution: Serhii Nazarenko, Lithuanian Energy Institute

Dissertation title: Patterns of low flow and hydrological drought risk assessment in Lithuanian rivers under climate change

Science area, field of science: Technological Sciences, Environmental Engineering, T004

Defense of the dissertation: 2024-02-21, 10:00 a.m., Lithuanian Energy Institute, AK-202 auditorium, Breslaujos st. 3, Kaunas, Lithuania.

Scientific Supervisor: Dr. Jūratė Kriaučiūnienė (Lithuanian Energy Institute, Technological Sciences, Environmental Engineering, T004)

Dissertation Defense Board of Environmental Engineering Science Field:

• Chairperson – Prof. Dr. Žaneta Stasiškienė (Kaunas University of Technology, Technological Sciences, Environmental Engineering, T004)
• Prof. Dr. Agrita Briede (University of Latvia, Latvia, Natural Sciences, Physical Geography, N006)
• Prof. Dr. Inga Dailidienė (Klaipėda University, Natural Sciences, Physical Geography, N006)
• Prof. Dr. Jolanta Dvarionienė (Kaunas University of Technology, Technological Sciences, Environmental Engineering, T004)
• Dr. Egidijus Kasiulis (Vytautas Magnus University, Technological Sciences, Environmental Engineering, T004)

The doctoral dissertation is available on the internet and at the library of Kaunas University of Technology (Gedimino st. 50, Kaunas).

Annotation
With climate change, the question of human impact on rivers and their usage becomes acute, making the determination of minimum river flow essential for addressing technical or environmental challenges. However, depending on the purpose, this can be done through the identification of hydrological drought, low flow, or even river intermittency. This study investigates changes in rivers’ low flow, including river intermittency and hydrological drought in Lithuania, and assesses their interoperability. Despite extensive research at regional and global levels, there is often a lack of understanding at the local level, especially regarding hydrological drought forecasting and the hydrological drought risk assessment. Within the scope of the work, a historical analysis of changes in low flow in Lithuanian rivers was conducted, with a separate analysis on river intermittency. The investigation of hydrological drought was carried out for the 1961-2020 period using the Streamflow Drought Index (SDI) and the Standardized Water Level Index (SWLI). Additionally, hydrological drought forecasting was performed for 6 Lithuanian rivers using the HBV software. Finally, GIS software was utilized to analyze Lithuania’s catchments and identify territories with the highest risk of hydrological drought. Given the limited studies on hydrological drought in Lithuania, this research aims to fill critical gaps, offering insights into intermittent rivers, changes in low flow due to climate change, and a comprehensive hydrological drought risk assessment. The results provide valuable information for policymakers, water resource managers, and stakeholders, aiding sustainable river management and guiding adaptation strategies.