TY  - JOUR
A1  - Wang, Wei-shi
A1  - Oswald, Sascha
A1  - Gräff, Thomas
A1  - Lensing, Hermann Josef
A1  - Liu, Tie
A1  - Strasser, Daniel
A1  - Munz, Matthias
T1  - Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport
JF  - Hydrogeology journal : official journal of the International Association of Hydrogeologists
N2  - Bank filtration (BF) is an established indirect water-treatment technology. The quality of water gained via BF depends on the subsurface capture zone, the mixing ratio (river water versus ambient groundwater), spatial and temporal distribution of subsurface travel times, and subsurface temperature patterns. Surface-water infiltration into the adjacent aquifer is determined by the local hydraulic gradient and riverbed permeability, which could be altered by natural clogging, scouring and artificial decolmation processes. The seasonal behaviour of a BF system in Germany, and its development during and about 6 months after decolmation (canal reconstruction), was observed with a long-term monitoring programme. To quantify the spatial and temporal variation in the BF system, a transient flow and heat transport model was implemented and two model scenarios, 'with' and 'without' canal reconstruction, were generated. Overall, the simulated water heads and temperatures matched those observed. Increased hydraulic connection between the canal and aquifer caused by the canal reconstruction led to an increase of similar to 23% in the already high share of BF water abstracted by the nearby waterworks. Subsurface travel-time distribution substantially shifted towards shorter travel times. Flow paths with travel times <200 days increased by similar to 10% and those with <300 days by 15%. Generally, the periodic temperature signal, and the summer and winter temperature extrema, increased and penetrated deeper into the aquifer. The joint hydrological and thermal effects caused by the canal reconstruction might increase the potential of biodegradable compounds to further penetrate into the aquifer, also by potentially affecting the redox zonation in the aquifer.
KW  - bank filtration
KW  - groundwater
KW  - surface-water relations
KW  - groundwater modelling
Y1  - 2019
U6  - https://doi.org/10.1007/s10040-019-02063-3
SN  - 1431-2174
SN  - 1435-0157
VL  - 28
IS  - 2
SP  - 723
EP  - 743
PB  - Springer
CY  - Berlin ; Heidelberg [u.a.]
ER  -