Distributed Hydrological Simulation Based on VIC MODEL Over Yujiang River Basin

To gain a deeper understanding and forecast the alterations in water resources within the Yujiang River Basin, the Variable Infiltration Capacity (VIC) distributed hydrological model was employed to model the temporal and spatial patterns of soil moisture, evapotranspiration, runoff and other hydrometeorological elements across the basin. Three indicators, Efficiency Coefficient (NS), Correlation Coefficient (r) and Relative Deviation (BIAS), were chosen as metrics to assess the precision of the simulation outcomes. The VIC model outputs four hydrological elements, including precipitation, evapotranspiration, surface runoff, and underground base flow, and calculates the relative error of multi-year average water balance. The results show that during the validation period, for the daily runoff, NS was 0.71, r was 0.85, and the BIAS were both 11%. For the monthly runoff, NS was 0.83, r was 0.92, and BIAS were both 13%. In the calibration period, NS was 0.65, r was 0.81, and BIAS were both 6% for the daily runoff, and for the monthly runoff, NS = 0.76, r = 0.90, and BIAS were both 5%. In all grids of the Yujiang River Basin, the relative error of water balance was no more than 2.47%. This indicates that the application of the VIC model in the Yujiang River Basin is very suitable and shows good applicability in both time and space.