%0 Journal Article
%A Graf, Alexander
%A Bogena, Heye
%A Drüe, Clemens
%A Hardelauf, Horst
%A Pütz, Thomas
%A Heinemann, Günther
%A Vereecken, Harry
%T Spatiotemporal relations between water budget components and soil water content in a forested tributary catchment
%J Water resources research
%V 50
%N 6
%@ 0043-1397
%C Washington, DC
%I AGU
%M FZJ-2014-05371
%P 4837 - 4857
%D 2014
%X We examined 3 years of measured daily values of all major water budget components (precipitation P, potential evapotranspiration PET, actual evapotranspiration ET, and runoff R) and volumetric soil water content θ of a small, forested catchment located in the west of Germany. The spatial distribution of θ was determined from a wireless sensor network of 109 points with 3 measurement depths each; ET was calculated from eddy covariance tower measurements. The water budget was dominantly energy-limited, with ET amounting to approximately 90 % of PET, and a runoff ratio R/P of 56 %. P, ET and R closed the long-term water budget with a residual of 2% of precipitation. On the daily timescale, the residual of the water budget was larger than on the annual timescale, and explained to a moderate extent by θ (R² = 0.40). Wavelet analysis revealed sub-weekly timescales, presumably dominated by unaccounted fast-turnover storage terms such as interception, as a major source of uncertainty in water balance closure. At weekly resolution, soil water content explained more than half (R² = 0.62) of the residual. By means of combined empirical orthogonal function and cluster analysis, two slightly different spatial patterns of θ could be identified that were associated with mean θ values below and above 0.35 cm³/cm³, respectively. The timing of these patterns as well as the varying coherence between PET, ET and soil water content responded to changes in water availability, including a moderate response to the European drought in spring 2011.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000340430400017
%R 10.1002/2013WR014516
%U https://juser.fz-juelich.de/record/171809