Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.jhydrol.2016.05.012
Titel (primär) Analysis of riverbed temperatures to determine the geometry of subsurface water flow around in-stream geomorphological structures
Autor Munz, M.; Oswald, S.E.; Schmidt, C.
Quelle Journal of Hydrology
Erscheinungsjahr 2016
Department HDG
Band/Volume 539
Seite von 74
Seite bis 87
Sprache englisch
Keywords Temperature time series; Amplitude ratio; River–groundwater exchange; Hyporheic zone; In-stream geomorphological structures; River restoration
UFZ Querschnittsthemen RU2;
Abstract The analytical evaluation of diurnal temperature variation in riverbed sediments provides detailed information on exchange fluxes between rivers and groundwater. The underlying assumption of the stationary, one-dimensional vertical flow field is frequently violated in natural systems where subsurface water flow often has a significant horizontal component. In this paper, we present a new methodology for identifying the geometry of the subsurface flow field using vertical temperature profiles. The statistical analyses are based on model optimisation and selection and are used to evaluate the shape of vertical amplitude ratio profiles. The method was applied to multiple profiles measured around in-stream geomorphological structures in a losing reach of a gravel bed river. The predominant subsurface flow field was systematically categorised in purely vertical and horizontal (hyporheic, parafluvial) components. The results highlight that river groundwater exchange flux at the head, crest and tail of geomorphological structures significantly deviated from the one-dimensional vertical flow, due to a significant horizontal component. The geometry of the subsurface water flow depended on the position around the geomorphological structures and on the river level. The methodology presented in this paper features great potential for characterising the spatial patterns and temporal dynamics of complex subsurface flow geometries by using measured temperature time series in vertical profiles.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=17647
Munz, M., Oswald, S.E., Schmidt, C. (2016):
Analysis of riverbed temperatures to determine the geometry of subsurface water flow around in-stream geomorphological structures
J. Hydrol. 539 , 74 - 87 10.1016/j.jhydrol.2016.05.012