The effects of atmospheric moisture on the mural paintings of the Mogao Grottoes

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Publication Type:

Journal Article

Authors:

Hongshou Li; Wanfu Wang; Hongtao Zhan; Fei Qiu; Qinglin Guo; Shenli Sun; Guobin Zhang;

Source:

Studies in Conservation, Volume 62, Number 4, p.229-239 (2017)

Abstract:

The aim of this paper is to study the influence of atmospheric humidity and temperature on the mural paintings in the Mogao Grottoes of Dunhuang by measuring the weight of a simulated mural block. Under open conditions, the daily changes in the atmospheric humidity and temperature have an apparent effect on the water content of these murals. There exists an obvious water exchange between atmosphere and mural, that is, there is a ±43 g m−2 moisture absorption–desorption ‘breathing’ process between the two. Evapotranspiration from the tree-belt, precipitation, and extremely dry weather also have an effect on the moisture associated with a mural painting. If the cave is closed, a comparable study finds that closure can make the effects of temperature and humidity changes disappear. The mural water content in this case remains stable and the harm due to water-salt deterioration is greatly reduced. Under closed conditions, artificial condensation dehumidification and control of the cave's temperature and humidity stabilizes water activity in the mural paintings very effectively. This is a clear indication of the future steps required to protect the cave's cultural relics.