(Dept. 1) Ecohydrology and Biogeochemistry

The interactions within and between green water (in terrestrial systems) and blue water (lakes, rivers, and subsurface aquifers) affect in complex ways the habitats for organisms and the reactive transport of abiotic components. Aquatic and terrestrial systems are coupled at multiple spatio-temporal scales. The overall goal of the Department of Ecohydrology and Biogeochemistry is to understand the ecohydrological and biogeochemical processes of these connected land- and waterscapes in natural, rural and urban environments. Therefore, our research projects focus on the following core topics:

  • Interactions of  landscape-freshwater ecosystems
  • Physical and biogeochemical drivers under global change
  • Water security in disturbed and urban systems

In our research, we integrate different modelling approaches with data collected in field studies, in large-scale manipulation studies,  by long-term monitoring and in laboratory experiments. We study ecohydrological and biogeochemical processes using a variety of tracer techniques, particularly stable isotopes, and by measuring naturally dissolved solutes, conservative geogenic ions, trace organic matter, and nutrients. In doing so, we combine basic research with application aspects and aim to record and model the effects of climate and land use changes. With its laboratory infrastructure and expertise in the fields of inorganic and organic analysis as well as isotope measurement, the department performs a central function for the entire institute. To achieve our research goal, we combine our professional expertise from the research disciplines of hydrology, geochemistry, aquatic physics, ecology, environmental engineering, and geography.

Research groups

Georgiy Kirillin
Stephanie Spahr
Alexander Sukhodolov
Dörthe Tetzlaff
Markus Venohr

Department members

Selected publications

August 2025
Journal of Hydrology. - 662(2025)Part C, Art. 134083

Stepwise tracer-based hydrograph separation to quantify contributions of multiple sources of streamflow in a large glacierized catchment over the Tibetan Plateau

Guangxuan Li; Xi Chen; Man Gao; Zhicai Zhang; Chris Soulsby; Doerthe Tetzlaff; Yuyi Wang

The authors identified the sources of streamflow and their temporal dynamics in a glacierized catchment of the Tibetan Plateau using isotopic and geochemical signatures. They demonstrated that incorporation of high-resolution tracer data in an appropriate model structure can help resolve streamflow components and identify the dynamics of dominant recharge sources in cryosphere environments.

August 2025
Hydrology and Earth System Sciences. - 29(2025)15, S. 3569–3588

Consequences of the Aral Sea restoration for its present physical state: temperature, mixing, and oxygen regime

Georgiy B. Kirillin; Tom Shatwell; Alexander S. Izhitskiy

The Aral Sea is both an example of large-scale environmental degradation caused by human activity and a message of hope through its partial restoration. The field observations and model scenarios show that the restored part of the Aral Sea appears to be healthy in terms of vertical mixing and oxygenation, but small changes of water level or transparency could alter the entire ecosystem.

July 2025
Hydrological Processes. - 39(2025)7, Art. e70190

Urban Hydrological Connectivity and Response Patterns Across Timescales: An Integrated Time-Frequency Domain Analysis

Gregorio A. López Moreira Mazacotte; Dörthe Tetzlaff; Chris Soulsby

The authors investigated the interconnections of rainfall, groundwater and stream flow in the Wuhle river in Berlin using autocorrelation, cross-correlation and time-frequency analyses of long-term data. Despite the strong influence of urban storm drainage, they showed a high degree of persistence of the groundwater signals.

July 2025
Water Resources Research. - 61(2025)7, Art. e2025WR040525

Hydrological Connectivity Dominates NO3-N Cycling in Complex Landscapes – Insights From Integration of Isotopes and Water Quality Modeling

Songjun Wu; Doerthe Tetzlaff; Xiaoqiang Yang; Tobias Sauter; Chris Soulsby

The authors integrated isotope-aided with N modelling to quantify the (dis)connection of different flow paths and related biogeochemical transformations, which is important for land and water management. Hydrological connectivity controls N transformations by regulating soil moisture and available NO3-N for processing from upstream inflows. 

June 2025
Hydrology and Earth System Sciences. - 29(2025)12, 2707–2725

Understanding ecohydrology and biodiversity in aquatic nature-based solutions in urban streams and ponds through an integrative multi-tracer approach

Maria Magdalena Warter; Dörthe Tetzlaff; Chris Soulsby; Tobias Goldhammer; Daniel Gebler; Kati Vierikko; Michael T. Monaghan

The authors used stable water isotopes, hydrochemistry and eDNA in a novel, integrated tracer-approach to show how ecohydrological interactions and biodiversity in urban aquaNBS are influenced by urban water sources and connectivity. The direct linkages between hydrology and microbial patterns are highlighted, illustrating the sensitivity of aquaNBS to anthropogenic and climate influences.