(c) Infiltration increase process (d) Total water reduction process
Figure 10. Water quantity change when stopping pumping for 3600 days
At 3600 pumping days, when K = 15, 20, and 25 m/d, the base flow from zone 1 to zone 2 decreased to 0 for 1260 days, 1320 days and 1470 days, and the infiltration times were 330 days, 300 days and 300 days. The infiltration volumes were 7.56 m3/d, 9.11 m3/d and 41.12 m3/d, respectively.
In the 3600 days when pumping was stopped, when K=15, 20, and 25 m/d, the base flow from zone 1 to zone 2 reappeared for 5340 days, 4740 days, and 4440 days, respectively, and the time when the induced infiltration was 0 was 5430 days, 4860 days and 4530 days, respectively.
The cone of depression formed during pumping is also related to the difference in hydraulic conductivity. When K=15, 20, and 25 m/d, the water levels in the water level observation wells located 30 m away from the pumping wells are 2.73 m, 4.14 m, and 5.11 m, respectively, when pumping for 1500 days, which means that the smaller the hydraulic conductivity is, the faster the water level in the center of the cone of depression drops.
Similarly, we plotted base flow, reduced base flow, induced infiltration, and total water reduction versus time for the three different hydraulic conductivities, as shown in Figure 11. In the reduced base flow curve with time, the greater the hydraulic conductivity of the aquifer, the greater the reduced base flow, and the earlier the reduced base flow decreases when pumping is stopped at 3600 days, and the reduced base flow