Spatial and temporal water quality dynamics during baseflow periods - Source area and in-stream effects (J.Flade, M.Ulmen)

Problemstellung

During baseflow periods runoff source areas can change over time depending e.g. on storage depletion rates, actual wetness, groundwater level or local evapotranspiration rates. Due to the resulting space/time variant water fluxes, these effects are also expressed in the physico-chemical composition of surface waters. Understanding the interaction of time variant source areas and biogeochemical in-stream processes and the determination of resulting spatial and temporal signatures of stream water composition will improve the prediction and management of water quality at the catchment scale.

Ziel der Arbeit

The focus of this Master thesis is on quantitative determination of time-variant sub-catchment water and solute fluxes. Based on this analysis „Hot Spots“ of nutrient export and biogeochemical cycling will be identified.

Methode

In a 1.7 km² agricultural headwater catchment a dense artificial drainage network and a predominantly impervious streambed allow for analysing the impact of sub-catchments on stream discharge regarding contributing areas, landuse and nutrient (N,P) export.

Fieldmethods, such as discharge measurements, tracer applications and water sampling are accomplished by lab-methods(e.g. major ion analysis) and data- and GIS-analysis.

Betreuung

Tobias Schütz

Besondere Hinweise

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Kontakt

Tobias Schütz tobias.schuetz@hydrology.uni-freiburg.de Tel. +49 (0)761 / 203-3519

Herausforderung

The challenge of this thesis will be the development of field sampling strategies and finding correlations between observable processes and measurable topographical characteristics.

Sprache

Englisch / Deutsch frei wählbar

Literatur

Covino. T.P., B.L. McGlynn, and R. *McNamara. 2012. Land use / land cover and scale influences on in-stream nitrogen uptake kinetics. Journal of Geophysical Research - Biogeosciences. doi:10.1029/2011JG001874

Payn, R.A., M.N. Gooseff, B.L. McGlynn, S.M. Wondzell, and K.E. Bencala. 2012. Exploring changes in the spatial distribution of stream baseflow generation during a seasonal recession. Water Resources Research. doi:10.1029/2011WR011552

Basu, N. B., S. E. Thompson, et al. (2011). „Hydrologic and biogeochemical functioning of intensively managed catchments: A synthesis of top-down analyses.“ Water Resour. Res. 47: W00J15, doi:10.1029/2011WR010800