WANG Hui, SUN Yayong, HUANG Shifeng, MA Jianwei, YANG Yongmin

Abstract: Vegetation parameters are an important input of the distributed hydrological model and have a significant effect on the simulation of water cycle variables such as runoff and soil moisture. The paper took Naqu, Tibet as the study area, where the effects of Leaf Area Index (LAI) and Fractional Vegetation Cover (FVC) were estimated by MODIS data on the simulation accuracy of soil moisture content of top 15cm layer using VIC model. The results showed that the simulation accuracy of the surface soil moisture content based on dynamic LAI and FVC estimated by MODIS data is significantly improved compared with which based on static vegetation parameters, and the improvement is particularly evident during permafrost period. The Bias decreased from 0.101 cm3·cm-3 to 0.032 cm3·cm-3, RMSE decreased from 0.135 cm3·cm-3 to 0.071 cm3·cm-3, and R increased from 0.483 to 0.836 by using dynamic vegetation data. Further analysis showed that the two vegetation parameters had a certain influence on the simulation accuracy of VIC model for the surface soil water content,and the effect of FVC was more significant.

Keywords: VIC model; soil moisture content; vegetation data; distributed hydrological model

(Journal of China Institute of Water Resources and Hydropower Research, Vol. 16, No. 2, 2018)