The detailed physical processes involved in slowing glacier ablation by material cover remain poorly understood so far. In the present study, using the snow cover model SNOWPACK, the effect of geotextile cover on the energy and mass balance at the tongue of the Urumqi Glacier No. 1 (Chinese Tien Shan) was simulated between July 12, 2022 and August 31, 2022. The mass changes and the energy fluxes with and without material cover were compared. The results indicated that the geotextile covering reduced glacier ablation by approximately 68% compared to the ablation in the uncovered regions. The high solar reflectivity of the geotextile reduced the net short-wave radiation energy available for the melt by 45%. Thermal insulation of the geotextile reduced the sensible heat flux by 15%. In addition, the wet geotextile exerted a cooling effect through long-wave radiation and negative latent heat flux. This cooling effect reduced the energy available for ablation by 20%. Consequently, only 37% of the energy was used for melting compared to that used in the uncovered regions (67%). Sensitivity experiments revealed that the geotextile cover used at a thickness range of 0.045-0.090 m reduced the ice loss by approximately 68%-72%, and a further increase in the thickness of the geotextile cover led to little improvements. A higher temperature and greater wind speed increased glacier ablation, although their effects were small. When the precipitation was set to zero, it led to a significantly increased melt. Overall, the geotextile effectively protected the glacier tongue from rapid melting, and the observed results have provided inspiration for developing an effective and sustainable approach to protect the glaciers using geotextile cover.

Worldwide examination of glacier change is based on detailed observations from only a small number of glaciers. The ground-based detailed individual glacier monitoring is of strong need and extremely important in both regional and global scales. A long-term integrated multi-level monitoring has been carried out on Urumqi Glacier No. 1 (UG1) at the headwaters of the Urumqi River in the eastern Tianshan Mountains of Central Asia since 1959 by the Tianshan Glaciological Station, Chinese Acamedey of Sciences (CAS), and the glaciological datasets promise to be the best in China. The boundaries of all glacier zones moved up, resulting in a shrunk accumulation area. The stratigraphy features of the snowpack on the glacier were found to be significantly altered by climate warming. Mass balances of UG1 show accelerated mass loss since 1960, which were attributed to three mechanisms. The glacier has been contracting at an accelerated rate since 1962, resulting in a total reduction of 0.37 km(2) or 19.3% from 1962 to 2018. Glacier runoff measured at the UG1 hydrometeoro-logical station demonstrates a significant increase from 1959 to 2018 with a large interannual fluctuation, which is inversely correlated with the glacier's mass balance. This study analyzes on the changes in glacier zones, mass balance, area and length, and streamflow in the nival glacial catchment over the past 60 years. It provides critical insight into the processes and mechanisms of glacier recession in response to climate change. The results are not only representative of those glaciers in the Tianshan mountains, but also for the continental-type throughout the world. The direct observation data form an essential basis for evaluating mountain glacier changes and the impact of glacier shrinkage on water resources in the interior drainage rivers within the vast arid and semi-arid land in northwestern China as well as Central Asia.