Analyzing the effect of cryosphere processes on catchment hydrology through a modeling approach: a case study in the Heihe River basin, Northwest China

Abstract:

Understanding the changes in cryosphere processes on river discharge under climate change is very important for the water resources management in the high altitude cold regions. A distributed eco-hydrological model was developed and cryosphere processes were coupled with hydrological processes in the model simulation. Model validation shows that the model shows high skill in simulating the river discharge, soil moisture, soil temperature and heat flux. The study area is the Heihe River basin, the second largest inland river basin in China. Numerical experiment shows that the soil freezing/thawing shows significant impact of hydrological processes and it reduced base flow and increased peak flow. Hydrological changes of the past 50 years in the Heihe River were analyzed based on model simulation. Soil temperature was found to be increased and melting depth shows significant increasing trend. Due to the limited areas, glacier melting shows little impact on the runoff changes. However, the changes in frozen soil and the snow melting shows significant effects on the river discharge changes. The results highlights the importance of study of the cryosphere hydrology in understanding the hydrological changes in the high altitude cold regions.

Key words: the Heihe River basin, hydrological changes, Cryosphere processes