Numerical simulation of the flow velocity and change in the future of the SG4

Abstract

Based on glacier dynamic theory, a two-dimensional velocity field model is developed to apply for the Qilian Shuiguan River glacier no. 4 (SG4). Our analysis shows that the glacier bedrock slope and shape affect the ice flow velocity together. The hydrological parameter k was adjusted in the model to fit the measured average flow velocities in summer and winter. The simulated results show that parameter k has a considerable impact on the glacier surface velocity, indicating that the water pressure under the glacier’s base is a major factor leading to basal sliding and ice velocity. The simulation shows that the glacier thickness, bedrock slope, bedrock shape, and basal slide jointly effect the glacier movement. The annual average mass balance was used to forecast the changes over the next 50 years based on the continuity equation. The results forecast the shrinkage of nearly 400 m in the terminus and glacier area over the next 50 years; the longitudinal section will diminish by nearly 29.2 %, and the average thickness will decrease by 47 %. If the effective glacier hydrology and geothermal temperature changes are taken into account, the actual retreat will be more substantial than that shown in our model.