Media365
A layer of artificial fabric reduced melting on a section of China’s Dagu Glacier by 15% over one year, as per the study. Researchers covered about 500 square metres of Dagu Glacier No. 17 with non-woven geotextile in August 2020 and monitored changes in the ice through October 2021.According to the research published in Remote Sensing, titled ‘Applying Artificial Cover to Reduce Melting in Dagu Glacier in the Eastern Qinghai-Tibetan Plateau’, the covered area lost less ice than nearby uncovered sections, although the material became less effective over time. During the first two months, melting was reduced by 27%. In a later two-month comparison, the reduction was 8%. The researchers linked the decline partly to a fall in the fabric’s ability to reflect sunlight and said cost and difficult access limited wider use on the Qinghai-Tibetan Plateau.
Researchers installed a 500-square-metre fabric cover on Dagu Glacier
Researchers installed the geotextile on 5 August 2020 along the glacier’s main flowline, about 50 metres from its terminus. The covered patch measured 500 square metres, equivalent to around 1% of the glacier’s total area. The team chose non-woven geotextile made from synthetic fibres because earlier research had found that this material offered strong insulation performance.The fabric was carried by gondola to an altitude of about 4,800 metres, then taken to the site by workers. Researchers secured the rolls together and fixed them in place with ropes and bags containing stones. They compared the covered ice with nearby uncovered areas using field measurements, terrestrial laser scanning and drone surveys.
Fabric cover reduced Dagu Glacier’s melting by 27% in two months
The difference between the covered and uncovered ice became clear within two months. By 17 October 2020, the covered surface stood an average of 0.46 metres higher than the surrounding uncovered surface. Measurements showed that the uncovered area melted at 1.9 centimetres per day, compared with 1.2 centimetres per day beneath the fabric. The researchers calculated that the cover reduced melting by 27% during this period and preserved about 178 cubic metres of ice. These results showed that the fabric had slowed ice loss during the initial observation period overall.
Dagu Glacier cover reduced annual melting by 15%
Monitoring over the following year found that the fabric continued to limit melting, but the difference narrowed. Terrestrial laser scans comparing October 2020 with October 2021 showed an average surface elevation change of 2.7 metres in uncovered areas and 2.3 metres in the protected section.The researchers calculated an annual reduction in melting of 15%. Drone surveys also compared changes between August and October 2021. During those two months, the covered area lost an average of 1.1 metres in elevation, while the uncovered area lost 1.2 metres. This represented an 8% reduction in melting, compared with the 27% reduction recorded in the first two months after installation during the study.
Glacier blanket loses reflectivity over time
The researchers measured a decline in the fabric’s albedo, or ability to reflect sunlight, from 0.71 in October 2020 to 0.39 in October 2021. They said this reduced reflectivity meant the material absorbed more solar energy and became less effective at protecting the ice.Deposited impurities and staining may also have contributed, while low temperatures and humidity could cause the fabric to crack. The study said these effects of ageing needed further investigation. The researchers also highlighted practical limits: high costs, difficult access to high-altitude glaciers, and the challenge of removing fabric that freezes to the ice.
