Abstract: Streamflow of the mountainous catchments on northern slope of the Tianshan Mountains is mainly contributed by snowmelt in spring and summer. In this study,the Urumqi River,Manas Rives and Kuytun River basins recharged mainly by snowmelt on northern slope of the Tianshan Mountains were selected to model the daily snowmelt runoff. A snowmelt runoff model (SRM) was used to simulate the daily runoff with the hydrological and meteorological data and snow/ice remote sensing images. The melt season from March to August in the hydrological year of 2007 was selected as the calibration period,and the same seasons in 2005 and 2006 were selected as the validation periods. Results indicated that,during both the calibration and validation periods,the SRM performed well in evaluating the daily snowmelt runoff in the three mountainous catchments. During the simulation period,the average values of R² and D_V for the three catchments were 0.85 and 9.42% respectively. During the validation periods,in the year of 2006,the average value of R² reached 0.72 and the average D_V remained 13.3% for the three catchments; in the year of 2005,the average values of R² and D_V for the three catchments were 0.78 and 4.85% respectively. Hence,it could be concluded safely that the calibration of SRM parameters was reasonable and the SRM is well established for practical application in all the three data-scarce mountainous catchments.

Key words: daily snowmelt runoff, simulation, snowmelt runoff model, mountainous catchment, northern slope of the Tianshan Mountains