Abstract:

Environmental factors play an important role in influencing on water evaporation in cave．The effect of temperature and humidity on water evaporation and its mechanism were analyzed by controlling temperature and relative humidity inside the 72 Cave of Dunhuang Mogao Grottoes，then the external environmental factors which affect water evaporation according to the water evaporation mechanism of surrounding rock were discussed． The results show that the change of 2.0 ℃ temperature inside the cave had a significant influence on water evaporation，and the amount of evaporation would increase more than 1 time in a short time．The high temperature and evaporation caused the humidity increase inside the cave． Consequently，the global warming will have serious adverse impacts on grotto culture relics．The precipitation increasing in Dunhuang area will increase the possibility of murals salt activation in the process of humidity climate．The geographical position，geothermal energy，terrain structure，surrounding rock porosity and cave structure of the Mogao Grottoes have great influences on water evaporation of surrounding rock． This article reveals the key reasons for Mogao Grottoes murals better preservation from environmental factors so far，and will provide a new idea for better conservation of the heritage．

Key words: Mogao Grottoes, environmental factors, evaporation, influence

摘要：

环境因子对洞窟水分蒸发有重要影响在敦煌莫高窟72窟蒸发水分的收集过程中，通过对窟内温度和湿度的控制，分析窟内温湿度对水分蒸发的影响及作用机理，并根据围岩水分蒸发机理，探讨影响水分蒸发的外部环境因子。结果表明，洞窟2．0 ℃的温度变化即可对水分蒸发产生显著影响，短期内蒸发量可增大1倍以上温度高蒸发量大，可导致窟内相对湿度增加，因此目前全球性的气温升高对洞窟文物将产生不利影响敦煌地区降雨量的增加增大了空气潮湿过程激活壁画盐分的可能。莫高窟所处的地理位置、地热、地形结构、围岩孔隙度和洞窟结构本身对围岩水分蒸发有重要影响本文从环境因素揭示了莫高窟壁画能够保存至今的关键原因，为今后洞窟文物的更好保护提供了新思路。

关键词: 莫高窟, 环境因子, 蒸发, 影响