As shown in Fig. 4, the formula for the local meteoric water line (LMWL) established based on the data of precipitation isotopes obtained from 1986 to 2013 is δ2H = 8.29δ18O + 7.44, and the correlation coefficient is 0.93. Compared with the global meteoric water line (GMWL) formula proposed by the IAEA-World Meteorological Organization and Craig (δ2H = 8δ18O + 10), the collected 115 samples of precipitation isotopes are all located near the GMWL, and the majority of the samples are found to be on the upper left of the GMWL. In addition, the slope of the LMWL is 8.29, which is higher than the slope of the GMWL of 8. The shift in slope reflects a different degree of non-equilibrium fractionation in Wuhan than the global average during the experiment (Chen et al. , 2016).