Data for: Hydrological connectivity regulates nitrogen transformation within a meandering driven hyporheic zone under contrasting hydrological conditions

Along each transect, three monitoring points were installed, with one in the middle of river channel, and one on each bank 2 m away from the river edge. For each instream point at C1 (inlet), C3 (apex) and C5 (outlet), three PVC piezometers with 5 cm diameter were installed to depths of 20 cm, 50 cm and 100 cm below the riverbed surface to observe groundwater heads at multiple depths. For the instream points at C2 and C4, one PVC piezometer was installed at the depth of 100 cm below the riverbed surface.

For the monitoring points on each bank, one piezometer was installed to 150 cm depth below the ground surface. Along the transect at the meander apex (T3), we established two more piezometers in the inner bank of the meander, located 6 m and 10 m away from the river edge.