The uniqueness of place and processes across a catchment cause problems in physically based hydrological models. One approach to solve that issue is the idea of catchments being an organized system. Within such organized system, patterns and structures have coevolved over time, are still present, and might hydrologically respond/function in distinct ways. How can such functional units in space be delineated from each other? How far do they react similar or dissimilar to precipitation input or solar radiation forces? What are the site characteristics that govern similarities? The composition of stable water isotopes in porewater across soil profiles (isotope profiles) seem to be promising tool to answer these questions.
The aim of the study is to compare isotope profiles at 48 locations of different geology, land use, and topography in a mess-scale watershed in Luxembourg. Similarity measures will be applied to specify how much the distinct sites differ from each other and if there are certain patterns across the study area. As a next step, the isotope profiles will be used to infer the hydrological processes in the subsurface at the sample sites and their possible relations to the site characteristics (vegetation, soil properties, topography, etc) will be analyzed.
To get the porewater isotope content across a soil profile, soil cores will be taken during a one to two weeks sampling campaign at the 48 pre-selected sample sites. Of these soil cores, soil samples in 5 cm intervals will be sealed in a plastic bag and analyzed for its isotope concentration of the pore water with an well developed equilibration method in the laboratory. The statistical methodology will cover similarity measures as well as regression models.
Markus Weiler und Matthias Sprenger
The fieldwork will take place in the Attert catchment in Luxembourg and it will last one to two weeks. The work is embedded in the CAOS-project and close contact to the other projects is ensured (http://www.caos-project.de).
Markus Weiler email@example.com Tel. +49 (0)761 / 203-3530
Field work, laboratory work, statistical analysis, isotope hydrology
Englisch or German