Recent progress on studies on cryospheric hydrological processes changes in China

The significant changes in the cryosphere have produced a series of effects on the cryospheric hydrological processes. This paper comprehensively reviews the recent 20 years, especially the new progress in the research on the changes in cryospheric hydrological processes in China, which mainly include glacial meltwater, snowmelt runoff, and frozen ground hydrology. The main progresses in the study on changes in glacial meltwater manifest as:a comprehensive study on glacial meltwater at different scales was carried out, it was found that the glacial meltwater showed continuously increase, and whether the "peak point" of the glacial meltwater have appeared has scientifically identified and some basic understandings has obtained, and the modelling on glacial meltwater process had made significant progress. In the study on snowmelt runoff changes, the snowmelt runoff contribution rate to river runoff in various basins were basically grasped by estimating the snowmelt runoff and found that the snowmelt runoff changes in China vary greatly, and it increased in some basins while decreased in some basins. The changes in the start melting period in China are universal with other basins in the world, and the prominent feature is the advance of the peak value. In the study of frozen ground hydrology, the studies on the relationship between surface water, interflow in active layer soil, supra-permafrost water revealed the coupling mechanism of gravity and thermodynamics in the formation of runoff in permafrost regions. The impacts of permafrost change on surface runoff has already appeared, which mainly appears as increase in the winter (dry season) runoff. It also found that the permafrost degradation has a direct replenishment effect on river runoff, and the amount of recharge may have reached a certain level in some basins.