373 / 2024-02-29 22:41:33

The simulation of snowmelt runoff in the source region of Yangtze River by MODIS and SRM

source region of Yangtze River; snow cover; snowmelt runoff simulation; MODIS; SRM

In the context of the river management and in view of climate change, it is important to study the theoretical and practical significance of snow cover and snowmelt runoff in alpine regions. The headwater region of Yangtze River is a typical high elevation region where snowmelt is an important composition of its channel runoff during the snowmelt period. This study aims at applying the Snowmelt Runoff Model (SRM) for the source region of Yangtze River in the snowmelt season (from March to August). Snow cover is one of the most important input variables for SRM. Because of the difficulty of terrestrial monitoring and measuring the snow coverage of large areas, satellite images are used as an alternative for mapping snow-covered areas. With geographic information system and remote sensing techniques, the snow-cover ratio of different elevation zones and the according depletion curves of snow coverage were obtained in the source region of Yangtze River using MODIS (Moderate-resolution Imaging Spectroradiometer) 8-day snow products and SRTM-DEM (elevation) data. The WinSRM version 1.10 was utilized to simulate the runoff in the source region of Yangtze River during the snowmelt season based on the hydrological and meteorological data observed in 2006. The NashSutcliffe coefficient of determination (R2) and volume difference (DV) are used for quality assessment of the SRM. The results show a good correlation between the measured and computed runoff in the Source region of Yangtze River . In addition, the sensitivity of the main variables (snow-cover depletion curves, temperature and precipitation) and parameters (degree-day factor, recession coefficient, runoff coefficients, time lag, critical temperature and temperature lapse rate) were analyzed. These findings will be useful for hydrological cycle research in the Source region of Yangtze River.