Figure 9. Histograms of ΔGST for 6 years of pumping with coupling depths from 2 m (top) to 90 m (bottom).
As mentioned in section 1, Smerdon and Stieglitz (2006) pointed out that the selection of BBCP depends on the time scale of interest. Khorsandi et al. (2014) tested the effect of BBCP (12, 24, 75, and 150 m) on subsurface heat storage based on the integrated modeling using the coupled CLM and ParflowE without considering the perturbations from human activities. Their results showed the cumulative heat storage in subsurface for different BBCPs is almost the same during the first five years of simulation. In this study, in the one-year simulation without pumping, GST from different scenarios are also similar (Figures 10a and 10c), which is consistent with Khorsandi et al. (2014) and indicates that the effect of coupling depth can be neglected at a short time-scale without human disturbance in the integrated modeling. In Figure 10, the difference of GST (ΔGST) for each scenario relative to L4 are in the left column while those relative to L6 are in the right column. The first row is for the year without pumping while the second row is for the first year of pumping. There is an obvious truncation of the root zone in L4, thus the distributions of ΔGST relative to L4 show a larger range than those relative to L6. Additional discussion about the truncation of the root zone is provided in section 3.4. Even in Figure 10a, the coincidence of the distributions also indicates the small difference of GST in the year without pumping among scenarios except L4.