A Coupled Glacier‐Hydrology Model and Its Application in Eastern Pamir

Abstract

AbstractAn energy‐balance glacier‐melt scheme was coupled with the Variable Infiltration Capacity hydrology model (VIC‐glacier). The coupled model was setup at 30 m × 30 m grids and applied in the Muji basin in eastern Pamir. The model was validated with field measurements of albedo, glacier mass balance, and river runoff. The VIC‐glacier model showed a good correspondence with the observations in incoming shortwave radiation and albedo, with R2 of 0.70 and 0.32, respectively, during August–October 2012. Simulated glacier mass balance exhibited overall good agreements with the observations in ablation seasons, with R2 of 0.89 and root‐mean‐square error of 162.12 mm w.e. during 2011–2015. The model also reproduced discharge records, with R2 of 0.70–0.84, Nash‐Sutcliffe efficiency of 0.56–0.81, root‐mean‐square error of 0.29–0.45 m3/s, and negative relative error of 13.73–18.76% in melt seasons of 2014–2015. The glaciers in Muji basin had a low mean net radiation of 40 W/m2, large negative latent heat fluxes of −32 W/m2, and low melt energy of −21 W/m2 in ablation seasons, resembling the energy partitioning generally found in continental climates. About 60% of the positive energy supply was consumed by latent heat fluxes on the glaciers in Muji basin, while only about 40% of the positive energy supply was used for melting. Glaciers in the Muji basin experienced a mass balance of −812.18 mm over 2011–2015, corresponding to a water release of 4.42 × 106 m3.The VIC‐glacier model has a good potential of broader utility for the large basins with limited meteorological observations.