SWEHydro Model and AMSR-E observations: an effective tool to reconstruct snowmelt runoff timing and magnitude

摘要

Snowmelt timing and snow water equivalent (SWE) from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) are used as inputs to the SWEHydro model to simulate spring snowmelt runoff in high-latitude, snow-dominated drainages. AMSR-E data are used to determine the timing of melt onset and snow saturation based on changes in brightness temperature (Tb) and diurnal amplitude variations (DAV). Pre-melt SWE data is combined with terrain information and melt rate estimates to calculate runoff. The model uses four parameters: snowmelt rate during and after melt transition (defined by Tb and DAV thresholds), and flow timing during and after melt transition. The model effectively simulates spring freshet, peak timing and magnitude in basins lacking sufficient meteorological measurements. Simulated freshet timing is strongly related to snowmelt timing, and the modelled hydrograph is most dependent on the flow timing parameter. We compare the model response in the Pelly and Stewart tributaries to the Yukon River to evaluate model parameters under varying conditions.