TY  - JOUR
AU  - Diouf, Ousmane Coly
AU  - Weihermüller, Lutz
AU  - Diedhiou, Mathias
AU  - Vereecken, Harry
AU  - Faye, Seynabou Cissé
AU  - Faye, Sérigne
AU  - Sylla, Samba Ndao
TI  - Modelling groundwater evapotranspiration in a shallow aquifer in a semi-arid environment
JO  - Journal of hydrology
VL  - 587
SN  - 0022-1694
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2020-01941
SP  - 124967 -
PY  - 2020
AB  - The use of diurnal or seasonal water table fluctuation (WTF) to estimate groundwater evapotranspiration (ETG) at different land uses and climate conditions is increasing applied in ecohydrological studies. In this study, we applied the WTF method for a shallow aquifer in an urbanized area in Senegal over the dry season 2000–2013.To analyze the applicability and validity of the WTF method for this site, and to understand the impact of the parameters used in this method, the unsaturated /saturated system was first simulated using the HYDRUS 1D model. The drawdown of the water table ranges from 18.1 to 113.2 cm and 10.4 to 101.9 cm for a bare soil and a perennial grass scenario and is highly related to the annual rainfall of the previous rainy season. The results indicate that the mean daily FAO-PM reference evapotranspiration rates for this area ranged from 2 to 4 mmd−1 and that the estimated actual evapotranspiration (ETa) from the HYDRUS 1D model ranged between 0.22 to 1.11 and 0.23 to 1.27 mmd−1 in bare soil and vegetative condition, respectively. ETa and ETG were well correlated for the vegetated scenario. However, the WTF method slightly overestimates ETa fluxes in the bare soil scenario. The study shows that the decline of ETa with water table depth can be simulated by an exponential function. The overall results indicate that higher ETa values were observed when the water table is shallow, suggesting that ETa is mainly driven by the water table depth at this site.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000568819100061
DO  - DOI:10.1016/j.jhydrol.2020.124967
UR  - https://juser.fz-juelich.de/record/875310
ER  -