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Reducing nitrate leaching using agricultural management policy maps: How to develop them?

PhD defence, Thursday 23 January 2020. Ioannis Varvaris.

2020.01.23 | Sunitha Satkunam

Ioannis Varvaris

Schematic illustration of hydrological processes in vadose zone in an agricultural field with intensive topographical gradients and drainage sequences discharging in open surface water body and recharging the shallow and deep aquifers.

During his PhD studies, Ioannis worked on modelling the soil water regime and solute transport processes in clayey tile-drained agricultural landscapes in Denmark. Before considering all the complex biogeochemical dynamic processes that take place in the vadose and the saturated zone, water flow and solute transport models for conservative chemicals should be built. Ioannis studied the capabilities and the weaknesses of all the available models, since depending on the processes that are the target for the modeling, the appropriate approach should be selected. Besides an appropriate model choice, the parameterization of the model has a decisive role in the actual performance of the selected approach. Ioannis suggested a concept for fast and inexpensive parameterization for covering the absence of knowledge regarding the input parameters in water flow models for simulating the actual and cumulative tile-drainage discharge in agricultural landscapes. The same suggested parameterizing concept was further used for simulating the water balance dynamics and solute transport in different scales.

The new research findings contribute to the soil science and hydrology areas as tool for fast parameterization of water flow and solute transport models.

The PhD degree was completed at the Department of Agroecology, Faculty of Technical Sciences, Aarhus University.

This resumé was prepared by the PhD student

Time: Thursday 23 January 2020 at 10:00
Place: 8814-3050, AU Foulum, Blichers Allé 20, 8830 Tjele
Title of PhD thesis: Water flow dynamics and solute transport across hydrotopographical gradients and drainage sequences in agricultural landscapes
Contact information: Ioannis Varvaris, e-mail: ioannisvarvaris@agro.au.dk, tel.: +45 24403054
Members of the assessment committee: 
University Distinguished Professor P.A. Ty Ferré, Department of Hydrology & Atmospheric Science, The University of Arizona
Associate professor Shoichiro Hamamoto, Department of Biological and Environmental Engineering, The University of Tokyo
Associate professor Lars Elsgaard, Department of Agroecology, Aarhus University (chair)
Main supervisor:
Associate professor Bo V. Iversen, Department of Agroecology, Aarhus University, Denmark
Senior researcher Christen Duus Børgesen, Department of Agroecology, Aarhus University, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Science and Technology/GSST, Ny Munkegade 120, building 1521, 8000 Aarhus C.

PhD defence
12183 / i43