Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1007/s10040-020-02225-8
Lizenz creative commons licence
Titel (primär) Structural controls on the hydrogeological functioning of a floodplain
Autor Martin, S.; Klingler, S.; Dietrich, P. ORCID logo ; Leven, C.; Cirpka, O.A.
Quelle Hydrogeology Journal
Erscheinungsjahr 2020
Department MET
Band/Volume 28
Heft 8
Seite von 2675
Seite bis 2696
Sprache englisch
Keywords Groundwater flow; Conceptual models; Floodplain; Sedimentary architecture; Biogeochemical turnover
Abstract Floodplains are often conceptualized as homogeneous sediment bodies which connect streams with their respective catchment and buffer agricultural inputs. This has led to a general bias within the hydrological community towards research on sites where the floodplain is a clear conduit for groundwater flow. In humid temperate regions of central Europe, floodplains have experienced rapid environmental changes since the last glaciation, yielding significant bedrock weathering and predominantly fine-grained, highly stratified hillslope and floodplain sediments. Such heterogeneous sedimentary architecture leads to conceptual ambiguities in the interpretation of the hydrogeological functioning of floodplains, thus raising the question: Do floodplains act as barriers or conduits to groundwater flow? This study analyzes the Ammer floodplain close to Tübingen in south-western Germany as a representative mid-section floodplain in a temperate climate where the regional bedrock-geology is dominated by mudstones. Geological, geophysical, and geochemical characterization and monitoring techniques were combined to shed light on the internal geological structure as a key control modulating the floodplain hydrology. Two partially separate groundwater systems were identified: a gravel body at the bottom of the Quaternary sediments and a Holocene confined tufaceous aquifer, separated by low-permeability clays. Despite flow being predominantly along-valley, sulfate concentrations in the floodplain aquifers showed evidence of a strong connection to the gypsum-bearing hillslope, particularly where tributary valley sediments are present (e.g., alluvial fans). Results from a floodplain water balance suggest the hillslope- and floodplain-aquifer material act as a barrier to hillslope groundwater recharge, where a large fraction may be bypassing the local floodplain groundwater system.
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Martin, S., Klingler, S., Dietrich, P., Leven, C., Cirpka, O.A. (2020):
Structural controls on the hydrogeological functioning of a floodplain
Hydrogeol. J. 28 (8), 2675 - 2696 10.1007/s10040-020-02225-8