Arbeitsgruppe Berger

I think that the education of young people is of fundamental importance for our future. In a world full of "now" and "fast", I feel that raising awareness for our environment, therewith developing interest in solving complex issues, and concurrently guiding students to acquire knowledge, will help us to make a better tomorrow.

From my own experience, I know that following lectures is sometimes not easy, if the topic may not seem relevant or too complicated (especially on Friday afternoons). This is why I try to offer a good balance in my lectures by combining: 1) plain, old-school lectures (to provide a solid background and motivation on the topic and methods), 2) collaborative and guided exercises (to get a feeling how to achieve a result), and 3) motivation to study the aspect to the students' interest on their own (through optional homework). I am confident that the synthesis of 1+2+3 > 6.

• Juliane Hendrich: Kostenvergleich von thermischen und druckbetriebenen Entsalzungsverfahren für die Aufbereitung saliner Grundwässer. BSc Thesis. Technische Universität Dresden, 2019.

• Annalena Werner: Trinkwassermanagement auf Inseln unter Berücksichtigung von Standortfaktoren und zukünftige Herausforderung aufgrund des Klimawandels. BSc Thesis. Technische Universität Dresden, 2018.

• Felix Vollberg: Einflussnahme des submarinen Grundwasserabflusses auf die Aktivität pathogener Vibrio spp.-Bakterien im marinen Sediment. Master Thesis. Universität Bremen, 2018.

• Luciana Scrinzi: Water and Salt Balance of Vadamarachchi: salinity drivers for a brackish coastal lagoon in interaction with groundwater. Master Thesis jointly supervised with Acacia Water (The Netherlands). Technische Universität Dresden, 2018.

• Nandini Vasanth Raman: Impact of exposure to low dose micropollutants on microbial biomass activity and community structure and fate of micropollutants in groundwater ecosystems. Master Thesis jointly supervised with the HelmholtzZentrum München (Institute for Groundwater Ecology). Technische Universität Dresden, 2018.

• Laura Elisa Herr: Examination of suitable desalination processes for injection into hydraulic barriers. Master Thesis jointly supervised with the Institute for Chair of Process Engineering in Hydro Sciences (TUD). Technische Universität Dresden, 2018.

• Pia Ebeling: Measures for seawater-intrusion remediation in shallow aquifers. Master Thesis. Technische Universität Dresden, 2018.

• Laslo Städtler: Investigating heat transport as an indicator for groundwater flow and surface water interactions in a protected wetland system using Distributed Temperature Sensing (DTS) and modelling. Master Thesis jointly supervised with the British Geological Survey and the University of Birmingham. Technische Universität Dresden, 2017.
• Elena Hubert: Bewertung von Verfahren der Regionalisierung von Grundwasserhöchstständen und Ableitung von Orientierungswerten für Bemessungsgrundwasserstände. Master Thesis. Technische Universität Freiberg, 2017.    
• Maria Bölicke: Assessing the influence of non-steady pumping on the sea water intrusion length. Bachelor Thesis. Technische Universität Dresden, 2017.
• Malte Ilgauds: Dichtegetriebene Verteilung von Wasser in der Wassersäule infolge submarinen und sublakrustinen Grundwasserzutritts und Möglichkeiten der Darstellung. Bachelor Thesis. Hochschule für Forstwirtschaft Rottenburg, 2017.
• Astha Bista: Implementation of Heterogeneous Highresolution Saturated Groundwater Flow and Mass Transport Model for the Test Site Pirna for Analyzing Multiple Tracer Tests. Master Thesis. Technische Universität Dresden, 2015.
• Linnet Chepkemei Ndiema: Evaluation of hydrogeological data and conception of a groundwater model for a field site in the south eastern part of Dresden, Saxony. Master Thesis. Technische Universität Dresden, 2015.
• Robert Ladwig: Optimale Bewirtschaftung arider Küstenaquifere durch Einsatz dichteabhängiger Grundwasserströmungsmodellierung und Methoden der künstlichen. Master Thesis. Technische Universität Dresden, 2015.
• Chao Li: Conception of a high-resolution saturated model for the test site Pirna. Master Thesis. Technische Universitat Dresden, 2014.
• Genua Yusef: Investigating the Influence of Landside Boundary Condition Types on Saline Intrusion in Combination with Different Coastal Shelf Shapes. Master Thesis. Study Course Hydro Science & Engineering, Technische Universität Dresden, 2014.
• Marvin Baekisapa: Feasibility Study Regarding the Potential Use of Groundwater for Water Supply on the Solomon Islands. Master Thesis. Technische Universität Dresden, 2013.
• Raneem Madi: Scenario-based simulation of infiltration at a test site in Ad-Dahna desert in Saudi Arabia. Master Thesis. Technische Universität Dresden & Helmholtz-Zentrum für Umweltforschung Halle, 2012.
• Bernhard Scheliga: Modellgestützte Untersuchung mariner Salzwasserintrusion in Abhängigkeit der Küstenform. Diplomarbeit. Technische Universität Dresden & Helmholtz-Zentrum für Umweltforschung Leipzig, 2012.
• Julia Krumm: Model-based Analysis and Prediction of Groundwater Recharge Using LARSIM and HYDRUS-1D. Master Thesis. Technische Universität Dresden & HYDRON GmbH Karlsruhe, 2011.
• Laura Kruschwitz: Untersuchungen zum Auswaschungsverhalten von NaCl aus dem wassergesättigtem Sedimentporenraum. Bachelor-Arbeit. Technische Universität Dresden, 2011.
• Hannes Kühlcke: Numerische Modellierung und Grundwasserbilanzierung in einer landwirtschaftlich genutzten Küstenregion im nördlichen Oman. Diplomarbeit. Dresden, Technische Universität Dresden & Helmholtz-Zentrum für Umweltforschung Leipzig, 2011.
• Anne-Katrin Röseler: Gestaltung von Wasserhaushaltsschichten zur Reduzierung der Grundwasserneubildung auf Kippenflächen am Beispiel eines Pilotversuchs auf der Kippe Witznitz. Diplomarbeit. TU Dresden & Dresdner Grundwasserforschungszentrum. Dresden, 2011.
• Oliver Männicke: An Experimental Study of Stable Saltwater Upconing. Diplomarbeit. TU Dresden & Flinders University Australia. Dresden, 2010.
• Martin Seidel: Assessment of Large-scale Interaction Between Groundwater and the Gambia River for an Integrated Water Resources Management (IWRM). Diplomarbeit. TU Dresden. Dresden, 2010.
• Len v. Scherenberg: Assessment of the Risk of Saline Intrusion into the Gateway Wellfield, Hermanus, Western Cape, South Africa - The application of analytical approaches and density dependent flow modelling in a fractured rock environment. Diplomarbeit. TU Dresden & Umvoto Africa. Dresden, 2010.

• Water in (semi-)arid regions
• Groundwater quantity and quality in coastal areas
• Numerical modeling in the saturated and unsaturated zone
• Simulation of groundwater flow and transport processes
• Density driven and variable viscosity flow in porous media
• Parameterization, interpolation and mesh generation in concurrence with hydro-geological structuring

Reviewed Publications

• Zheng, T., Gao, S., Liu, T., Meng, Q., Zheng, X., Walther, M., Lu, C. (2023): Dynamic influence of land reclamation on the nitrate contamination and saltwater redistribution. Science of The Total Environment 883: 163605

• Chang, Q., Zheng, T., Zheng, X., Gao, C., Song, X., Walther, M. (2023). Repulsion driven by groundwater level difference around cutoff walls on seawater intrusion in unconfined aquifers. Science of The Total Environment 874: 162535

• Fang, Y., Qian, J., Zheng, T., Wang, H., Zheng, X., Walther, M. (2023). Submarine groundwater discharge in response to the construction of subsurface physical barriers in coastal aquifers. Journal of Hydrology 617: 129010

• Liu, S., Yang, Z., Liu, Y., Zheng, X., Yang, H., Walther, M., Zheng, T. (2022): Improvement of dissolved organic nitrogen extraction accuracy in unsaturated zones. Hydrological Processes 36(9), e14680.

• Fang, Y., Zheng, T., Guo, B., Zhan, H., Wang, H., Zheng, X., Walther, M. (2022): Transformation in the Stability of Tide-induced Upper Saline Plume Driven by Transient External Forcing. Water Resources Research 58: e2021WR031331.

• Wimmler, M.-C., Vovides, A.G., Peters, R., Walther, M., Nadezhdina, N., Berger, U. (2022) Root grafts matter for inter-tree water exchange – a quantification of water translocation between root grafted mangrove trees using field data and model based indication. Annals of Botany: mcac074.

• Fang, Y., Zheng, T., Wang, H., Zheng, X., Walther, M. (2022): Nitrate transport behavior behind subsurface dams under varying hydrological conditions. Science of the total environment, 155903.

• Fang, Y., Zheng, T., Wang, H., Zheng, X., Walther, M. (2022): Influence of Dynamically Stable-unstable Flow on Seawater Intrusion and Submarine Groundwater Discharge over Tidal and Seasonal Cycles. Journal of Geophysical Research: Oceans.

• Chang, Q., Zheng, T., Gao, C., Zheng, X., Walther, M. (2022): How to cope with downstream groundwater deterioration induced by cutoff walls in coastal aquifers. Journal of Hydrology 610:127804.

• Zheng, T., Gao, M., Chang, Q., Zheng, X., Walther, M. (2022): Dynamic Desalination of Intruding Seawater After Construction of Cut-Off Walls in a Coastal Unconfined Aquifer. Frontiers in Marine Science 9, 857807.

• Wimmler, M.-C., Bathmann, J., Peters, R., Jiang, J., Walther, M., Lovelock, C. E., Berger, U. (2021): Plant-soil feedbacks in mangrove ecosystems: establishing links between empirical and modelling studies. Trees 35, 1423-1438.
• Fang, Y., Zheng, T., Wang, H., Guan, R., Zheng, X., Walther, M. (2021): Experimental and numerical evidence on the influence of tidal activity on the effectiveness of subsurface dams. Journal of Hydrology.
• Sun, Q., Zheng, T., Zheng, X., Walther, M. (2021): Effectiveness and comparison of physical barriers on seawater intrusion and nitrate accumulation in upstream aquifers. Journal of Contaminant Hydrology 243, 103913.
• Bathmann, J., Peters, R., Reef, R., Berger, U., Walther, M., Lovelock, C. E. (2021): Modelling mangrove forest structure and species composition over tidal inundation gradients: The feedback between plant water use and porewater salinity in an arid mangrove ecosystem. Agricultural and Forest Meteorology 308–309: 108547.
• Binder, M., A. Hahnewald, F. Händel, H. Prommer, C. Engelmann, D. Burghardt, P. Stock, F. Tritschler, R. Liedl, and M. Walther. “Single‐Rate Dual‐Domain Mass Transfer Model: Elucidating Temperature Effects.” Water Resources Research57, no. 4 (April 2021). https://doi.org/10.1029/2020WR029474.
• Chang, Q., T. Zheng, Y. Chen, X. Zheng, and M. Walther. “Influence of Inland Freshwater Influx on the Natural Desalination of Coastal Aquifers with a Cutff Wall.” Desalination 499 (2021). https://doi.org/10.1016/j.desal.2020.114863
• Engelmann, Christian, Kaveh Sookhak Lari, Luisa Schmidt, Charles J. Werth, and Marc Walther. “Towards Predicting DNAPL Source Zone Formation to Improve Plume Assessment: Using Robust Laboratory and Numerical Experiments to Evaluate the Relevance of Retention Curve Characteristics.” Journal of Hazardous Materials 407 (April 2021): 124741. https://doi.org/10.1016/j.jhazmat.2020.124741.
• Fang, Yunhai, Tianyuan Zheng, Xilai Zheng, Huiyu Yang, Huan Wang, and Marc Walther. “Influence of Tide-Induced Unstable Flow on Seawater Intrusion and Submarine Groundwater Discharge.” Water Resources Research 57, no. 4 (2021): e2020WR029038. https://doi.org/10.1029/2020WR029038.
• Gao, Mingpeng, Tianyuan Zheng, Qinpeng Chang, Xilai Zheng, and Marc Walther. “Effects of Mixed Physical Barrier on Residual Saltwater Removal and Groundwater Discharge in Coastal Aquifers.” Hydrological Processes, 2021, e14263. https://doi.org/10.1002/hyp.14263.
• Henao Casas, José D., Fritz Kalwa, Marc Walther, and Randolf Rausch. “Stormwater Harvesting in Ephemeral Streams: How to Bypass Clogging and Unsaturated Layers.” Hydrogeology Journal, April 19, 2021. https://doi.org/10.1007/s10040-021-02345-9.
• Moosdorf, Nils, Michael Ernst Böttcher, Dini Adyasari, Ercan Erkul, Benjamin S. Gilfedder, Janek Greskowiak, Anna-Kathrina Jenner, et al. “A State-Of-The-Art Perspective on the Characterization of Subterranean Estuaries at the Regional Scale.” Frontiers in Earth Science 9 (May 14, 2021): 601293. https://doi.org/10.3389/feart.2021.601293.
• Rosentreter, Hanna, Marc Walther, and André Lerch. “Partial Desalination of Saline Groundwater: Comparison of Nanofiltration, Reverse Osmosis and Membrane Capacitive Deionisation.” Membranes 11, no. 2 (February 12, 2021): 126. https://doi.org/10.3390/membranes11020126.
• Sun, Qiguo, Tianyuan Zheng, Xilai Zheng, and Marc Walther. “Effects of Subsurface Barriers on Seawater Intrusion and Nitrate Accumulation in Coastal Aquifers.” Preprint. Preprints, February 5, 2021. https://doi.org/10.22541/au.161252403.31172601/v1.
• Zhang, Bo, Tianyuan Zheng, Xilai Zheng, and Marc Walther. “Utilization of Pit Lake on the Cleaning Process of Residual Saltwater in Unconfined Coastal Aquifers.” Science of The Total Environment 770 (2021): 144670. https://doi.org/10.1016/j.scitotenv.2020.144670.
• Zheng, Tianyuan, Xilai Zheng, Qinpeng Chang, Hongbin Zhan, and Marc Walther. “Timescale and Effectiveness of Residual Saltwater Desalinization Behind Subsurface Dams in an Unconfined Aquifer.” Water Resources Research 57, no. 2 (2021): e2020WR028493. https://doi.org/10.1029/2020WR028493.
• Jurado A., Walther M., Díaz˗Cruz M.S. (2021) Occurrence, Fate and Associated Risks of Organic Micropollutants from the Watch List of European Groundwaters. In: Morin-Crini N., Lichtfouse E., Crini G. (eds) Emerging Contaminants Vol. 1. Environmental Chemistry for a Sustainable World, vol 65. Springer, Cham. https://doi.org/10.1007/978-3-030-69079-3_2
• Rosentreter, H.,Walther, M., Lerch, A., 2021. Partial Desalination of Saline Groundwater: Comparison of Nanofiltration, Reverse Osmosis and Membrane Capacitive Deionisation. Membranes 11, no. 2: 126. https://doi.org/10.3390/membranes11020126.
• Vollberg, F., Walther, M., Gärdes, A., Moosdorf, N., 2019. Modeling the Potential of Submarine Groundwater Discharge to Facilitate Growth of Vibrio cholerae Bacteria. Hydrology 6, 14. https://doi.org/10.3390/hydrology6020039
• Sun, Q., Zheng, T., Zheng, X., Chang, Q., Walther, M., 2019. Influence of a subsurface cut-off wall on nitrate contamination in an unconfined aquifer. Journal of Hydrology 575, 234–243. https://doi.org/10.1016/j.jhydrol.2019.05.030
• Engelmann, C., Händel, F., Binder, M., Yadav, P.K., Dietrich, P., Liedl, R., Walther, M., 2019. The fate of DNAPL contaminants in non-consolidated subsurface systems – Discussion on the relevance of effective source zone geometries for plume propagation. Journal of Hazardous Materials 375, 233–240. https://doi.org/10.1016/j.jhazmat.2019.04.083 
• Jurado, A., Walther, M., Díaz-Cruz, M.S., 2019. Occurrence, fate and environmental risk assessment of the organic microcontaminants included in the Watch Lists set by EU Decisions 2015/495 and 2018/840 in the groundwater of Spain. Science of The Total Environment 663, 285–296. https://doi.org/10.1016/j.scitotenv.2019.01.270
• Yu, L., Wu, X., Zheng, X., Zheng, T., Xin, J., Walther, M., 2019. An index system constructed for ecological stress assessment of the coastal zone: A case study of Shandong, China. J. Environ. Manage. 232, 499–504. https://doi.org/10.1016/j.jenvman.2018.11.084
• Zinner, M., Rink, K., Jäkel, R., Feldhoff, K., Grunzke, R., Fischer, T., Song, R., Walther, M., Jejkal, T., Kolditz, O., Nagel, W.E., 2018. Revision Control and Automatic Documentation for the Development Numerical Models for Scientific Applications. Int. J. Adv. Softw. 11, 214–226.
• Jing, M., Heße, F., Kumar, R., Wang, W., Fischer, T., Walther, M., Zink, M., Zech, A., Samaniego, L., Kolditz, O., Attinger, S., 2018. Improved regional-scale groundwater representation by the coupling of the mesoscale Hydrologic Model (mHM v5.7) to the groundwater model OpenGeoSys (OGS). Geosci. Model Dev. 11, 1989–2007. https://doi.org/10.5194/gmd-11-1989-2018
• Miegel, K., Gräff, T., Franck, C., Salzmann, T., Bronstert, A., Walther, M., Oswald, S.E., 2017. Auswirkungen des Sturmhochwassers der Ostsee am 4./5. Januar 2017 auf das renaturierte Niedermoor „Hütelmoor und Heiligensee“ an der deutschen Ostseeküste. Hydrol. und Wasserbewirtschaftung 61, 232–243. doi.org/10.5675/HyWa_2017,4_2.
• Walther, M., Graf, T., Kolditz, O., Liedl, R., Post, V., 2017. How Significant is the Slope of the Sea-side Boundary for Modelling Seawater Intrusion in Coastal Aquifers? J. Hydrol. doi.org/10.1016/j.jhydrol.2017.02.031.
• Schulz, S., Walther, M., Michelsen, N., Rausch, R., Dirks, H., Al-Saud, M., Merz, R., Kolditz, O., Schüth, C., 2017. Improving large-scale groundwater models by considering fossil gradients. Adv. Water Resour. 103, 32–43. doi.org/10.1016/j.advwatres.2017.02.010.
• Selle, B., Gräff, T., Salzmann, T., Oswald, S.E., Walther, M., Miegel, K., (2016). Untersuchung eines renaturierten Mooreinzugsgebiets an der mecklenburgischen Ostseeküste - Teil II: Salzdynamik und Wasserhaushalt. Hydrol. und Wasserbewirtschaftung 60, 259–269. doi:10.5675/HyWa_2016,4_2.
• Zhi, G., Chen, Y., Liao, Z., Walther, M., Yuan, X. (2016). Comprehensive assessment of eutrophication status based on Monte Carlo–triangular fuzzy numbers model: site study of Dongting Lake, Mid-South China. Environ. Earth Sci. 75, 1011. doi.org/10.1007/s12665-016-5819-7.
• Stoeckl, L., M. Walther, and T. Graf (2016). A new numerical benchmark of a freshwater lens, Water Resour. Res., 52, doi:10.1002/2015WR017989.
• Fischer, T., Naumov, D., Sattler, S., Kolditz, O., and Walther, M. (2015). GO2OGS 1.0: a versatile workflow to integrate complex geological information with fault data into numerical simulation models, Geosci. Model Dev., 8, 3681-3694, doi.org/10.5194/gmd-8-3681-2015.
• Bilke, L., Fischer, T., Helbig, C., Krawczyk, C., Nagel, T., Naumov, D., Paulick, S., Rink, K., Sachse, A., Schelenz, S., Walther, M., Watanabe, N., Zehner, B., Ziesch, J., Kolditz, O. (2014). TESSIN VISLab—laboratory for scientific visualization. Environmental Earth Sciences. doi.org/10.1007/s12665-014-3785-5.
• Walther, M., Bilke, L., Delfs, J.-O., Graf, T., Grundmann, J., Kolditz, O., Liedl, R. (2014). Assessing the saltwater remediation potential of a three-dimensional, heterogeneous, coastal aquifer system. Environmental Earth Sciences. doi.org/10.1007/s12665-014-3253-2
• Walther, M., Solpuker, U., Böttcher, N., Kolditz, O., Liedl, R., Schwartz, F. W. (2013). Description and Verification of a Novel Flow and Transport Model for Silicate-Gel Emplacement. Journal of Contaminant Hydrology, 157, 1–10. doi.org/10.1016/j.jconhyd.2013.10.007
• Walther, M., Böttcher, N., & Liedl, R. (2012). A 3D interpolation algorithm for layered tilted geological formations using an adapted inverse distance weighting approach. ModelCare2011, Models - Repositories of Knowledge (pp. 119–126). Leipzig:  IAHS Publ. 355 (2012) ISBN 978-1-907161-34-6, 374.
• Kolditz, O., Görke, U.-J., Shao, H., & Wang, W. (2012). Thermo-Hydro-Mechanical-Chemical Processes in Porous Media: Benchmarks and Examples (Lecture Notes in Computational Science and Engineering). Springer. Link
• Walther, M., Delfs, J.-O., Grundmann, J., Kolditz, O., & Liedl, R. (2012). Saltwater Intrusion Modeling: Verification and Application to an Agricultural Coastal Arid Region in Oman. Journal of Computational and Applied Mathematics. http://dx.doi.org/10.1016/j.cam.2012.02.008.
• Kalbacher, T., Delfs, J.O., Shao, H., Wang, W., Walther, M., Samaniego, L., Schneider, C., Musolff, A., Centler, F., Sun, F., Hildebrandt, A., Liedl, R., Borchardt, D., Krebs, P., Kolditz, O. (2012): The IWAS-ToolBox: software coupling for an integrated water resources management, Environ. Earth Sci. 65 (5), 1367 - 1380. http://dx.doi.org/10.1007/s12665-011-1270-y.
• O. Kolditz, S. Bauer, L. Bilke, N. Böttcher, J.O. Delfs, T. Fischer, U.J. Görke, T. Kalbacher, G. Kosakowski, C.I. McDermott, C.H. Park, F. Radu, K. Rink, H. Shao, H.B. Shao, F. Sun, Y.Y. Sun, A.K. Singh, J. Taron, M. Walther, W. Wang, N. Watanabe, Y. Wu, M. Xie, B. Zehner: Technical Paper OpenGeoSys: An open source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media, Environmental Earth Sciences. http://dx.doi.org/10.1007/s12665-012-1546-x.
• Walther M., Fank J., Reimann T.: Tiefengestaffeltes Wasserprobenahmesystem zur spezifischen Beprobung der ungesättigten Zone, dem Kapillarsaum und der gesättigten Zone. Grundwasser 15(1), 19-31, 2010. http://dx.doi.org/10.1007/s00767-009-0129-6.

Talks

• Walther, M. (2018). Der Weg zur Juniorprofessur. In: HyWaTa - Hydrologisch-Wasserwirtschaftliche Tagung. Dresden, Germany.
• Walther, M., Händel, F., Kalbacher, T. (2018). Hydrogeologische Modellierung - schön, aber falsch. In: KGM-MODREG: Tagung Für Numerische Modellierung von Wasserfluss, Stofftransport Und Wärmeverlagerung in Seichtliegenden Grundwasserleitern – Praktische Umsetzung Bei Regionaler Betrachtung. Seggauberg, Austria.
• Walther, M., Stoeckl, L., Morgan, L. (2018). Is sea water intrusion by groundwater over-abstraction even worse than what we expected? Part 2: Understanding parameter sensitivity in field-scale. In: Saltwater Intrusion Meeting 2018, Dansk, Poland.
• Walther, M., Graf, T., Kolditz, O., Liedl, R., and Post, V. (2017). How Significant is the Slope of the Sea-side Boundary for Modelling Seawater Intrusion in Coastal Aquifers? In: European Geophysical Union General Assembly, Vienna

• Walther, M., 2016. Variable-Density Flow and transport in Porous Media - A Small Selection of Examples, In: Forstkolloquium. Tharandt, Germany.

• Walther, M., Händel, F., 2016. Variable density flow and transport in Saturated Porous Media, In: The Indian Institute of Technology. New Dehli, India.

• Walther, M. (2015). Variable-Density Flow Processes in Porous Media on Small, Medium and Regional Scales. In: Dresdner Grundwassertage 2015, Dresden, Germany.
• Walther, M., Bilke, L., Delfs, J.-O., Graf, T., Grundmann, J., Liedl, R., Kolditz, O. (2014). Evaluating Remediation Potential of a Salinized Heterogeneous Aquifer System Using Three-Dimensional, Density-Dependent Groundwater Modeling. In: Salt Water Intrusion Meeting (SWIM23), Husum, Germany, 2014.
• Stoeckl, L., Walther, M., Schneider, A., Yang, J., Graf, T.: Influence of geological heterogeneity on freshwater discharge in coastal aquifers – physical experiments and numerical modeling. In: Salt Water Intrusion Meeting (SWIM23), Husum, Germany, 2014.
• Walther, M., Bilke, L., Delfs, J.-O., Graf, T., Grundmann, J., Kolditz, O., Liedl, R.: Visualizing Saline Intrusion in a Three-Dimensional, Heterogeneous, Coastal Aquifer. In: Workshop on Visualisation in Environmental Sciences (EnvirVis), Leipzig, Germany, 2013.
• Walther, M., Graf, T., Kolditz, O., Liedl, R.: Discretizing a Thermohaline Double-Diffusive Rayleigh Regime. In: 3rd HydroGeoSphere Conference, Neuchatel, Switzerland, 2013.
• Walther, M., Delfs, J.-O., Graf, T., Al-Saidi, A., Grundmann, J., Kolditz, O., Liedl, R.: Case Study of Groundwater Resources Usage for a Coastal Arid Region in the Al Batinah, Oman. In: Hydrogeology of Arid Environments, Hannover, Germany, 2012.
• Walther, M., Seegert, J., Grundmann, J., Kloss, S., Schütze, N., Gerner, A., Lennartz, F., Schmitz, G., Kolditz, O., Liedl, R.: IWAS – International Water Research Alliance Saxony, Water Resources Management for Hydrologically Sensitive Regions. In: SHARP Sustainable Hydro Assessment & Groundwater Recharge Projects, 4th Partner Meeting Wroclaw/Dresden, POL/DE, 2011.
• Walther, M.; Kolditz, O.; Grundmann, J.; Liedl, R.: Large-scale Density-dependent Groundwater Modelling in Agriculturally Used Coastal Arid Regions. In: FEMTEC 2011, 3rd International Conference on Computational Methods in Engineering and Science, South Lake Tahoe 2011.
• Walther, M.; Kolditz, O.; Grundmann, J.; Liedl, R.: Grundwassermodellierung in küstennahen ariden Gebieten unter dem Einfluss der Intrusion marinen Salzwassers. In: Tagung der FH-DGG Tübingen 2010.
• Walther, M., Fank, J., Reimann, Th., Liedl, R.: Beprobung und Überwachung des gesamten Bereiches der ungesättigten und gesättigten Zone einschließlich des Kapillarsaums - Funktionsanalyse eines Probenahmesystems auf Basis numerischer Simulationen und zweijähriger Datenbasis. In: Forum Junge Hydrogeologen, Tagung der FH-DGG Tübingen 2010.
• Walther, M.; Kolditz, O.; Grundmann, J.; Liedl, R.: Groundwater Modeling in Coastal Arid Regions Under the Influence of Marine Saltwater Intrusion. In: EGU General Assembly 2010, held 2-7 May, 2010 in Vienna, Austria, p.12790.
• Walther, M., Fank, J., Reimann, Th., Liedl, R.: Messsystem zur Beprobung und Überwachung des gesamten Bereiches der ungesättigten und ges. Zone. In: 13. Gumpensteiner Lysimetertagung Raumberg-Gumpenstein - Bericht, Irdning 2009.

Posters

• Magri, F., Walther, M., Inbar, N., Moeller, P., Raggad, M., Roediger, T., Rosenthal, E., Shentsis, I., Siebert, C., Volpi, G.: 3D Coupled Thermal-Hydraulic Model of the Lower Yarmouk Gorge, Jordan Rift Valley. In: American Geological Union Fall Meeting 2017, New Orleans, LA, USA.
• Peters, R., Walther, M., and Berger, U. (2016). Coastal Hydrology # Ecosystems, An Obviously Linked Network. In Synthesis II Workshop From Dynamics Of Structure To Functions Of Complex Networks, Dresden, Germany.
• Walther, M., Stöckl, L., Heiss, J., Post, V., Graf, T., Kolditz, O., and Liedl, R. (2016). Numerical Simulation Of Submarine Groundwater Discharge Different Problems On Different Scales (As Usual). In DFG Rundgespräch Submariner Grundwasserabfluss, Delmenhorst, Germany.
• D. Naumov, T. Fischer, N. Böttcher, N. Watanabe, M. Walther, K. Rink, L. Bilke, H. Shao, O. Kolditz: OpenGeoSys: Performance-Oriented Computational Methods for Numerical Modeling of Flow in Large Hydrogeological Systems. In: American Geological Union Fall Meeting 2014, San Francisco, CA, USA.
• Walther, M., Solpuker, U., Böttcher, N. Kolditz, O., Liedl, R., Schwartz, FW.: Description and Verification of a Novel Flow and Transport Model for Silicate-Gel Emplacement (H13B-1324). In: AGU Fall Meeting 2013, San Francisco, CA, USA.
• Graf, T., Walther, M., Kolditz, O., Liedl, R.: Delineating Thermohaline Double-Diffusive Rayleigh Regimes (H13D-1378). In: AGU Fall Meeting 2013, San Francisco, CA, USA.
• Stoeckl, L., Walther, M., Schneider, A., Yang, J., Gaj, M., Graf, T.: Comparison of different numerical models using a two-dimensional density-driven benchmark of a freshwater lens (H33B-1349). In: AGU Fall Meeting 2013, San Francisco, CA, USA.
• Delfs, J.-O., Sachse, A., Gayler, S., Grathwohl, P., He, W., Jang, E., Kalbacher, T., Klein, C., Kolditz, O., Maier, U., Priesack, E., Rink, K., Selle, B., Shao, H., Singh, AK., Streck, T., Sun, Y., Wang, W., Walther, M.: An Open Source Framework for Coupled Hydro-Hydrogeo-Chemical Systems in Catchment Research (H43A-1414). In: AGU Fall Meeting 2013, San Francisco, CA, USA.
• Walther, M., Delfs, J.-O., Grundmann, J., Kolditz, O., Liedl, R.: Dichteabhängige Grundwassermodellierung auf Regionalskala: Modellstudie für eine landwirtschaftliche Küstenregion in der Al Batinah, Oman. In: FH‐DGG‐Tagung, Dresden, Germany, 2012.
• Philipp, A., Grundmann, J., Walther, M.: Flow Routing in Ephemeral Arid Rivers under the Influence of Transmission Losses and Groundwater Recharge Dams. In: Hydrogeology of Arid Environments, Hannover, Germany, 2012.
• Walther, M., Delfs, J.-O., Grundmann, J., Kolditz, O., Liedl, R.: Density-Dependent Saltwater Intrusion Modeling within an Integrated Water Resource Management for an Agricultural Used Coastal Arid Study Region in Oman. In: International Conference on Integrated Water Resources Management, Management of Water in a Changing World: Lessons Learnt and Innovative Perspectives, Dresden 2011.
• Walther, M., Delfs, J.-O., Grundmann, J., Kolditz, O., Liedl, R.: An Application of the Scientific Simulation Software OpenGeoSys: Three-Dimensional Density-Dependent Groundwater Modeling in Coastal Arid Regions. In: ModelCare 2011 Conference »Models – Repositories of Knowledge« Leipzig 2011.
• Walther, M., Fank, J., Reimann, Th., Liedl, R.: Beprobung und Überwachung des gesamten Bereiches der ungesättigten und gesättigten Zone einschließlich des Kapillarsaums - Funktionsanalyse eines Probenahmesystems auf Basis numerischer Simulationen und zweijähriger Datenbasis. In: Tagung der FH-DGG Tübingen 2010.

Proceedings

• Walther, M., Bilke, L., Delfs, J.-O., Graf, T., Grundmann, J., Liedl, R., Kolditz, O. (2014). Evaluating Remediation Potential of a Salinized Heterogeneous Aquifer System Using Three-Dimensional, Density-Dependent Groundwater Modeling. In: Salt Water Intrusion Meeting (SWIM23), Husum, Germany, 2014.
• Stoeckl, L., Walther, M., Schneider, A., Yang, J., Graf, T.: Influence of geological heterogeneity on freshwater discharge in coastal aquifers – physical experiments and numerical modeling. In: Salt Water Intrusion Meeting (SWIM23), Husum, Germany, 2014.
• Walther, M., Bilke, L., Delfs, J.-O., Graf, T., Grundmann, J., Kolditz, O., Liedl, R.: Visualizing Saline Intrusion in a Three-Dimensional, Heterogeneous, Coastal Aquifer. In: Workshop on Visualisation in Environmental Sciences (EnvirVis), Leipzig, Germany, 2013.
• Brettschneider, M., Grundmann, J., Schütze, N., Walther, M.: Development of Surrogate Models for reproduction of complex numerical simulation models and application in a water resource management system. In: The New Zealand Hydrological Society Annual Conference (NZHS Conference) at Dunedin (New Zealand) 2010.
• Schmitz G., Al-Hattaly S., Grundmann J., Schütze N., Walther, M.: An Integrated Assessment-, Prognoses-, Planning- and Managementtool (APPM) for Sustainable Arid Zone Water Management. In: 9th Gulf Water Conference 2010, Muscat, Oman.
• Fank, J., Walther, M., Reimann, Th., Liedl, R.: Tiefengestaffeltes Wasserprobenahmesystem unter ackerbaulich genutzten Flächen. In: PANGEO 2008 - Abstracts / Kurzfassungen: Journal of Alpine Geology, 49: 22-23, Wien 2008.

Reviewing for Advances in Water Resources (ADWR), Journal of Hydrology (JoH), Hydrology and Earth System Sciences (HESS), Environmental Earth Sciences (EES), Hydrogeology Journal, Grundwasser.

Regular member and member of the advisory board of the Fachsektion Hydrogeologie e.V. in der Deutschen Geologischen Gesellschaft (FH-DGGV e.V.), regular member of the International Association of Hydrogeologists (IAH), member of the Freunde und Förderer der Technischen Universität Dresden e.V., member of the Freunde und Förderer des UFZ e.V.

DFG funded CAWR-Project (TUD Chair of Forest Biometrics and Forest Systems Analysis, UFZ Department Environmental Informatics) to gain information on subsurface aquifer structures from surface vegetation patterns

Project runtime: 07/2018 - 06/2021

Rationale:

• Traditional forest models do not consider below-ground processes of plant competition for limited resources
• Aquifer parameterization is limited to point information on larger scales

Aims:

• Gain insight into the relationships between visible vegetation patterns like tree allometry, species composition and zonation and subsurface aquifer structures and potential gradients by tidal and groundwater
• Understand the physical mechanisms of belowground plant interaction and derive a new plant interaction approach for individual based simulation models
• Adopt vegetation zonation patterns to gain information on subsurface aquifer structures and parameterization

Latest Publications:

• Peters, R., Walther, M., Lovelock, C., Jiang, J., Berger, U., 2020. The interplay between vegetation and water in mangroves: new perspectives for mangrove stand modelling and ecological research. Wetlands Ecol Manage. https://doi.org/10.1007/s11273-020-09733-0

• Bathmann, J., Peters, R., Naumov, D., Fischer, T., Berger, U., Walther, M., 2020. The MANgrove–GroundwAter feedback model (MANGA) – Describing belowground competition based on first principles. Ecological Modelling 11.

• Peters, R., Olagoke, A., & Berger, U. (2018). A new mechanistic theory of self-thinning: Adaptive behaviour of plants explains the shape and slope of self-thinning trajectories. Ecological Modelling 390, 1–9.

Below is one of our latest simulation results (model pyMANGA) with a parametrization for a study site near Giralia, AUS, proving the concept of the project, ie. that zonation emerges from subsurface properties (here as a result of soil salinity influenced by tidal activity).

DFG funded CAWR-Project (TUD Institute for Groundwater Management, Professorships Groundwater Management & Contaminant Hydrology; UFZ Department Monitoring and Exploration Technologies) to understand influence of internal and external stressors on contaminant source zone formation and their implications for final plume extension

Project runtime: 03/2018 - 02/2021

Project page: Link to ResearchGate

Rationale:

• DNAPL source zone formation largely unknown in detail, usually approximated as point or line source in numerical models 
• Compensation of uncertainty through calibration in plume length

Aims:

• Understand influences of temporal dynamics (e.g. recharge) and spatial heterogeneity (deterministic, e.g. layering) during source zone formation 
• Derive effective source zone geometries based on major site specifics

Latest Publications:

• Engelmann, C., Schmidt, L., Werth, C.J., Walther, M., 2019. Quantification of uncertainties from image processing and analysis in laboratory-scale DNAPL release studies evaluated by reflective optical imaging. Water 11. https://doi.org/10.3390/w11112274
• Engelmann, C., Händel, F., Binder, M., Yadav, P.K., Dietrich, P., Liedl, R., Walther, M., 2019. The fate of DNAPL contaminants in non-consolidated subsurface systems – Discussion on the relevance of effective source zone geometries for plume propagation. Journal of Hazardous Materials 375, 233–240. https://doi.org/10.1016/j.jhazmat.2019.04.083

© Martin Pohl

Project has successfully finished in beginning of 2019.

Subproject in BMBF-funded project: Urban Catchments

Runtime 12/2016 - 12/2018

Latest publication:

• Pohl, M., Engelmann, C., Walther, M., 2019. WP-E: groundwater systems, in: Sachse, A., Liao, Z., Hu, W., Dai, X., Kolditz, O. (Eds.), Chinese Water Systems: Volume 2: Managing Water Resources for Urban Catchments: Chaohu. Springer International Publishing, Cham, pp. 231–242. https://doi.org/10.1007/978-3-319-97568-9_7

DFG funded CAWR-Project (TUD Chair of Groundwater Management, TUD Chair of Urban Water Management, UFZ Department Monitoring and Exploration Technologies) to deduct optimal groundwater monitoring strategies from sewer structure characteristics

Project runtime: 01/2019 - 12/2021

© C. Engelmann

Rationale:

• Determination of sewer leakage required to secure groundwater quality; urban groundwater monitoring capabilities limited by space and money

• Multiple point-type, long-term sewer leackage represents linear-type source term of contaminants at groundwater surface

Aims:

• Understand spatial relation between point-type pipe leakage and linear-type groundwater contamination

• Characterize sewer network structures with geometric measures (network parameters)

• Determine aquifer areas of highest contamination potential with respect to different sewer network types (and network parameters)

• Deduct optimal / optimize existing groundwater monitoring system based on sewer network structure

Below is an animation from the modelling tool HYDRUS showing the spill of a sewer pipe and the migration of a reactive contaminant through the unsaturated zone. This helps us to understand the spreading of a contaminant plume through the unsaturated soil and deduct the area affected by the pollution at the groundwater surface.

SAB (Sächsische Aufbaubank) funded F&E-Project ( TUD Institute of Hydraulic Engineering and Technical Hydromechanics,  Kurt-Schwabe-Institut für Mess- und Sensortechnik e.V., Weischlitzer Tiefbau und Umweltschutz GmbH, M&S Umweltprojekt GmbH) for the development of a robust prediction system for dike failure.

Project runtime: 10/2019 - 12/2021

Rationale:

• Dikes are important element of hydraulic engineering and need to be designed in a way to withstand diverse cases of loading

• Current regulations only concern steady state cases without respecting possible water saturation from precipitation in upper, unsaturated soil horizons in dikes, which could lead to critical failure (sliding, dam break)

Aims:

• Determine key parameters and their sensitivity for dike stability

• Utilize laboratory scale and mid-size experimental setups in combination with numerical simulation software (unsaturated zone flow, mechanical stability)

• Deduct critical stability criteria for precipitation-influenced scenarios in real-world settings

• Software development to provide a robust prediction tool for dike stability under variable dike saturation

© A. Albers / M. Walther

Project in funded by Landesrektorenkonferenz Sachsen to promote use of electronic and blended learning for the activation of students during self-studying phases.

Runtime 10/2019 - 09/2020

Latest publication:

• Poster for project meeting of "Digital Fellows" on 22 January 2020