Table 2 Hausman test result of deformation time series of the measure points in the area of Sect. 3 of the dam

b = consistent under Ho and Ha; obtained from xtreg

B = inconsistent under Ha, efficient under Ho; obtained from xtreg

Test: Ho: difference in coefficients not systematic

chi2(2) = (b−B)’[(V_b−V_B)^(−1)](b−B) = 9.14

Prob > chi2 = 0.0104