Toward high-spatial resolution hydrological modeling for China: Calibrating the VIC model

Abstract. High-resolution hydrological modeling is important for understanding fundamental terrestrial processes associated with the effects of climate variability and human activities on water resources availability. However, the spatial resolution of current hydrological modeling studies is mostly constrained to a relative coarse resolution (~ 10–100 km) and they are therefore unable to address many of the water-related issues facing society. In this study, a high resolution (0.0625º, ~ 6 km) hydrological modeling for China was developed based on the Variable Infiltration Capacity (VIC) model, spanning the period from January of 1970 to June of 2016. Distinct from other modeling studies, the parameters in the VIC model were updated using newly developed soil and vegetation datasets, and an effective parameter estimation scheme was used to transfer parameters from gauged to ungauged basins. Simulated runoff, evapotranspiration (ET), and soil moisture (SM) were extensively evaluated using in-situ observations, which indicated that there was a great improvement due to the updated model parameters. The spatial and temporal distributions of simulated ET and SM were also consistent with remote sensing retrievals. Moreover, this high-resolution modeling is capable of capturing flood and drought events with respect to their timing, duration, and spatial extent. This study shows that the hydrological datasets produced from this high-resolution modeling are useful for understanding long-term climate change and water resource security. It also has great potential for coupling with the China Land Data Simulation System to achieve real-time hydrological forecasts across China.