3.1 Determination of parameters and evaluation of the simulation
According to a time-related division, the daily-scale distributed hydrological model of the Qinhe River Basin was established, and the measured runoff from Runcheng Station was used to calibrate and test. Regarding the adjustment of parameters, a reasonable range was selected for each according to variations in hydrological processes during the flood season. Table 1 gives the results of GBHM simulation parameters.
A single index is inadequate for the evaluation of results from a hydrological simulation because it can be affected by the evaluation method. Consequently, in the present study, the NASH efficiency coefficient E_N, ratio of absolute error to daily runoff S, and correlation coefficient P were utilized as indexes to evaluate the results of the established hydrological model (Lyu et al., 2019). The established model simulation results and associated reliability checks are shown in Figure 4.
Table 1. GBHM modeling parameter values (Yang et al., 2002; Lyu et al., 2019)