Bahar Bahrami - Helmholtz-Centre for Environmental Research

Dipl.-Ing. Bahar Bahrami

Contact

Department of Computational Hydrosystems (CHS)
Helmholtz-Zentrum für Umweltforschung - UFZ

Permoserstraße 15
04318 Leipzig

Building 7.1, Room 4.13
Phone +49 341 235-1001

bahareh.bahrami@ufz.de

Research Interests

Coupling of water and carbon cycles
Hydroclimatology and hydrological extreme assessments
Application of geo-Statistical methods and optimization algorithms
Application of GIS and Remote Sensing technology in environmental analysis

Projects

I am a water engineer and environmental modeller driven by a fundamental question: how do complex environmental systems respond to a changing climate, and how can we better predict their future? My research combines process-based, data-intensive, and data-driven modelling to improve our understanding of the interactions between water and carbon cycles under a changing world.
As the lead developer of the Parsimonious Canopy Model (PCM v1.0), I designed and implemented a process-based ecosystem model by integrating mathematical formulations from the scientific literature into a unified computational framework capable of simulating above-ground carbon cycle dynamics in forest ecosystems under changing environmental conditions. I evaluate models against real-world observations, from ground-based eddy-covariance measurements to satellite-derived products, and use sensitivity analysis to identify the processes that drive model behaviour. The model was designed to interface with hydrological modelling frameworks, enabling the representation of coupled water and carbon cycle processes.

I am driven by the belief that scientifically rigorous and computationally efficient modelling can advance our understanding of environmental change and contribute to the sustainable management of our natural resources.

Academic career

Since 2019 Researcher

2018 Dipl.-Ing., Water Engineering and Management, Vienna, Austria

2016 Visiting Scholar, University of Illinois at Urbana-Champaign (UIUC), Illinois, United States

M.Sc., Climatology in Environmental Planning, University of Tarbiat Modares (TMU), Tehran, Iran; B.Sc., Natural Resources Engineering

Publication

Bahar Bahrami, Anke Hildebrandt, Stephan Thober, Corinna Rebmann, Rico Fischer, Luis Samaniego, Oldrich Rakovec, and Rohini Kumar:

Developing a parsimonious canopy model (PCM v1.0) to predict forest gross primary productivity and leaf area index of deciduous broad-leaved forest.

Geoscientific Model Development, 15, 6957–6980.

https://doi.org/10.5194/gmd-15-6957-2022

Bahrami, B., Kumar, R., Thober, S., Hildebrandt, A., Fischer, R., Samaniego, L., Rebmann, C.:

Predicting forest gross primary productivity and leaf area index by coupling light use efficiency and leaf phenology in a parsimonious canopy model.

Oral presentation, EGU General Assembly 2022, Vienna, Austria. Abstract EGU22-8844

10.5194/egusphere-egu22-8844

Bahrami, B., Kumar, R., Thober, S., Rebmann, C., Fischer, R., Samaniego, L., Kleidon-Hildebrandt, A., and Attinger, S.:

Augmenting the multiscale hydrologic modeling system with adequate vegetation dynamics for improved representation of coupled water and carbon cycles.

EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-11605,

https://doi.org/10.5194/egusphere-egu2020-11605

Bahar Bahrami, Rohini Kumar, Stephan Thober, Anke Hildebrandt, Luis Samaniego, Corinna Rebmann, Rico Fischer and Sabine Attinger:

A low complexity vegetation model to simulate Leaf Area Index and Gross Primary Productivity for use in hydrological models.

iPoster presentation, AGU Fall Meeting 2020, Online. Abstract B046-0004

https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/702115

Contact

Head
Prof. Dr. Sabine Attinger
Department of Computational Hydrosystems
tbl-modmon@ufz.de

Deputy Head
Prof. Dr. Luis Samaniego
Department of Computational Hydrosystems
luis.samaniego@ufz.de

Assistance
Nora Pabst
Phone +49 341 6025-2367

Sindy Bleiholder
Phone +49 341 6025-1250

Susanne Gangloff
Phone +49 341 6025-2533

sekces@ufz.de

Permoserstraße 15 | 04318 Leipzig

News / Press

Aug 2025

New research published in Nature Food by Batool et al. (2025) analyses the effectiveness of EU nitrogen reduction targets. Under the “Farm to Fork” (F2F) strategy of the “Green Deal”, the EU Commission aims to reduce nutrient losses by 50% by 2030 by requiring EU countries to cut chemical fertiliser use by 20%. As shown in our work such a uniform reduction in fertilizer use would not be sufficient.

May 2024

New research published in Nature Communications by Hussian et al., (2024) emphasizes the game-changing potential of near-real-time and impact-based flood prediction. Their study demonstrates a 10-meter floodplain inundation hindcast of the 2021 European Summer Flood, showcasing a 17-hour lead time for better disaster preparedness. Impact-based early warnings can empower local authorities with crucial data on citizens at-risk for targeted emergency responses.

July 30, 2023

Hitze und Dürre - Interview with climate researcher Jakob Zscheischler
in Deutschlandfunk (only in German, 10:50 min) Link to interview

May 16, 2023

Start of ESA funded project 4DHydro

The overarching objective of 4DHydro is to foster collaborations between the Earth Observation (EO) water cycle community developing novel high-resolution EO data products, and the land surface and hydrological modelling community (LSM/HM) engaged in advancing hyperresolution modelling of the hydrological cycle at regional and continental scales. By involving several European institutions 4DHydro will assess and improve data sets of EO as well as synchronize EO products and LSM/HM models in order to improve predictions of the hydrological system. Overall, it will assist end-users and decisions-makers as well as the EU Destination Earth initiative. The project’s kick-off meeting will take place in Leipzig on 21st of June 2023.

Jan 30, 2023

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The following paper received the ASCE-EWRI 2023 Award for Best Case Study in the Journal of Hydrologic Engineering.

Mai, J. , B. A. Tolson, H. Shen, É. Gaborit, V. Fortin, N. Gasset, H. Awoye, T. A. Stadnyk, L. M. Fry, E. A. Bradley, F. Seglenieks, A. G. Temgoua, D. G. Princz, S. Gharari, A. Haghnegahdar, M. E. Elshamy, S. Razavi, M. Gauch, J. Lin, X. Ni, Y. Yuan, M. McLeod, N. B. Basu, R. Kumar, O. Rakovec, L. Samaniego, S. Attinger, N. K. Shrestha, P. Daggupati, T. Roy, S. Wi, T. Hunter, J. R. Craig, and A. Pietroniro (2021):
The Great Lakes Runoff Intercomparison Project Phase 3: Lake Erie (GRIP-E)
Journal of Hydrologic Engineering, 26(9), 05021020. Accepted Feb 16, 2021.

https://ascelibrary.org/doi/10.1061/%28ASCE%29HE.1943-5584.0002097

Dec 1, 2022

Award Poster Masooma Batool

Masooma Batool won the "Best student poster award" at the XXI International Nitrogen Workshop.
This conference, hosted by ETSIAAB, Universidad Politécnica de Madrid, brought together nearly 300 papers from authors from 40 countries in Madrid, Spain, October 24-28, 2022.
At the conference, Masooma and her colleagues presented long-term trends in soil nitrogen (N) surplus across Europe (1850-2019). Excess N provides information on the trends and spatial distribution of N surplus in soil systems across Europe, highlighting agricultural areas in Central Europe as nitrogen hotspots. These areas have undergone dramatic changes over the past 150 years. Importantly, we show that estimates of N surplus are subject to large uncertainties, requiring explicit consideration of these uncertainties when analyzing past trends in N surplus.

Nov 15, 2022

Earthrise - Mission Klima
How our research contributes to climate mitigation and adaptation is demonstrated in this WELT report.

Video at www.welt.de (only in German)

05:50': Hohes Holz research station
10:40': FORMIND in the Vislab
15:45': Fragmentation of forests
43:00': FORMIND and climate scenarios

Oct 12, 2022

Dr. Husain Najafi won the UFZ Young Scientist Award for Applied Research 2022. The award goes to him for his excellence and dedication in development of the operational drought forecasting system in Germany and investigation of 2021 summer flood predictability. Hydrological forecasting systems are the fundamental component of early warning systems - disaster risk reduction.

Older news are stored in the news archive.

New publications

Najafi, H., Shrestha, P.K., Rakovec, O. et al. High-resolution impact-based early warning system for riverine flooding. Nat Commun 15, 3726 (2024). https://doi.org/10.1038/s41467-024-48065-y
Henniger, H., Huth, A., Frank, K., & Bohn, F. J. (2023). Creating virtual forests around the globe and analysing their state space. Ecological Modelling, 483, 110404. https://doi.org/10.1016/j.ecolmodel.2023.110404

In this paper we present the "Forest Factory 2.0″ algorithm, which generates various virtual forest stands for different biomes on Earth. To demonstrate the potential of this approach, we analyse different forest-structure->ecosystem-function relationships across biomes.
Friedrich Boeing, Oldrich Rakovec, Rohini Kumar, Luis Samaniego, Martin Schrön, Anke Hildebrandt, Corinna Rebmann, Stephan Thober, Sebastian Müller, Steffen Zacharias, Heye Bogena, Katrin Schneider, Ralf Kiese, Sabine Attinger, and Andreas Marx. High-resolution drought simulations and comparison to soil moisture observations in Germany. Hydrol. Earth Syst. Sci., 26, 5137–5161, 2022. https://doi.org/10.5194/hess-26-5137-2022

In this paper, we deliver an evaluation of the second generation operational German drought monitor ( https://www.ufz.de/duerremonitor ) with a state-of-the-art compilation of observed soil moisture data from 40 locations and four different measurement methods in Germany. We show that the expressed stakeholder needs for higher resolution drought information at the one-kilometer scale can be met and that the agreement of simulated and observed soil moisture dynamics can be moderately improved.
Mahnken, M., Cailleret, M., Collalti, A., Trotta, C., Biondo, C., D’Andrea, E., ... & Reyer, C. P. O. (2022). Accuracy, realism and general applicability of European forest models. Global Change Biology. DOI: 10.1111/gcb.16384
Pacheco-Labrador, J., Weber, U., Ma, X., Mahecha, M. D., Carvalhais, N., Wirth, C., Huth, A., Bohn, F. J., Kraemer, G., Heiden, U., FunDivEUROPE members, and Migliavacca, M.: EVALUATING THE POTENTIAL OF DESIS TO INFER PLANT TAXONOMICAL AND FUNCTIONAL DIVERSITIES IN EUROPEAN FORESTS, Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVI-1/W1-2021, 49–55, 2022. DOI: 10.5194/isprs-archives-XLVI-1-W1-2021-49-2022
Bevacqua, E., De Michele, C., Manning, C., Couasnon, A., Ribeiro, A.F.S., Ramos, A.M., Vignotto, E., Bastos, A., Blesić, S., Durante, F., Hillier, J., Oliveira, S.C., Pinto, J.G., Ragno, E., Rivoire, P., Saunders, K., van der Wiel, K., Wu, W., Zhang, T., Zscheischler, J. (2021): Guidelines for Studying Diverse Types of Compound Weather and Climate Events. Earth Future. 10.1029/2021EF002340
Najafi H, Robertson AW, Massah Bavani AR, Irannejad P, Wanders N, Wood EF. Improved multi-model ensemble forecasts of Iran's precipitation and temperature using a hybrid dynamical-statistical approach during fall and winter seasons. Int
J Climatol. 2021;1–28. DOI: 10.1002/joc.7148

Hari, V., Rakovec, O., Markonis, Y. et al. Increased future occurrences of the exceptional 2018–2019 Central European drought under global warming. Sci Rep 10, 12207 (2020). DOI: 10.1038/s41598-020-68872-9

Schmidt, L., Heße, F., Attinger, S., Kumar, R., (2020): "Challenges in applying machine learning models for hydrological inference: A case study for flooding events across Germany", Water Resources Research DOI: 10.1029/2019WR025924

Jing, M., Kumar, R., Heße, F., Thober, S., Rakovec, O., Samaniego, L., Attinger, S., (2020): "Assessing the response of groundwater quantity and travel time distribution to 1.5, 2, and 3 °C global warming in a mesoscale central German basin", Hydrology and Earth System Sciences DOI: 10.5194/hess-24-1511-2020

Sep 2, 2022

The collaborative project "Standardisiertes Monitoring von Wachstumsreaktionen wichtiger Waldbaumarten auf klimatische Extremereignisse" (MW³) with participation of the UFZ will develop a standardized monitoring system and protocol to record growth responses of important Central European forest tree species with a focus on climatic extremes. Future extreme events and their impact on forest carbon fluxes in Germany will be analyzed using smart models.