Author(s): Keyi Wang; Jun Niu; Ji Chen
Linked Author(s): Ji Chen, Jun Niu
Keywords: Global terrestrial hydrological processes; Streamflow; Soil moisture; VIC model; Continental river basins
Abstract: This study presents a study of simulation of the global land surface hydrological processes (including streamflow, soil moisture, and evapotranspiration) at a daily temporal step and at 1° latitude-longitude spatial resolution for the period 1997-2008. We use the GTOPO30 DEM dataset with the 1 km spatial resolution to delineate the watersheds over the world. This study adopts a macro-scale hydrological model, Variable Infiltration Capacity (VIC), to simulate the terrestrial hydrological processes. To run the model, we need daily precipitation data, which are obtained from the Global Precipitation Climatology Project (GPCP), and the daily maximum temperature, the minimum temperature, and wind speeds, which are extracted from the NCAR/NCEP Reanalysis data. In addition, to set up the model, we need soil and vegetation parameters, which are directly from two established global soil and vegetation datasets. Using the observed hydrological data from five major continental river basins in the world (i. e., the Amazon River, the Mississippi River, the Yangtze River, the Yellow River, and the Nile River), this study analyzes the variation of precipitation, streamflow and soil moisture over the world, and then the relationships among terrestrial hydrological processes will be explored. The produced datasets from this study will benefit the regional hydrologic studies, especially in the regions where have limited hydrology observations and information. To evaluate the water availability over the land surface, the study also identifies the regions with the high sensitivity of water resources security, which will be valuable for improving our capability of preventing water-related natural hazards, such as floods and droughts. In addition, this study examines the natural trends of streamflow in highlighting the occurrences of hydrological extreme events (floods and droughts) for the major large-scale river basins.