2.3.1 Surface and subsurface runoff
For the two events occurred during the low drainage period, the reaction time of the subsurface tile drain are among the shortest of all the events of the year: 1h57 and 3h02 for the May 11th and the June 4th event, respectively (Table 4). The May 11th event is the only event of the year where the subsurface drain reacts before the surface drain: the surface runoff began 1h54 after the subsurface runoff.