西安建筑科技大学学报(自然科学版)

敦煌莫高窟是丝绸之路沿线一处重要的佛教文化遗址,以精美的壁画和塑像闻名于世界.降雨引起洞窟湿度变化极容易导致壁画盐类病害.通过环境监测试验分析不同等级降雨条件下洞窟湿度变化特征及潜在影响,并提出风险防范措施及建议.研究结果表明,不同等级降雨条件下,洞窟湿度变化均呈现上升-保持-下降三个阶段.前期降雨使湿度快速升高,后期降雨使湿度缓慢降低,高湿度保持时间随着降雨等级和降雨次数的增加而增加.降雨天气,水汽浓度梯度是水汽交换的主要动力.当 a_air>a_cave时,大气中的湿空气向洞窟内扩散,洞窟湿度增加.当a_air<a_cave时,洞窟内湿空气流向窟外,洞窟湿度逐渐降低.洞窟湿度大小及相对湿度超过62%的持续时间均表现为半封闭洞窟>封闭洞窟,小型洞窟>大型洞窟.为了预防洞窟湿度增加激活壁画盐害,建议当a_air=a_cave时实施洞窟环境调控,控制条件为RH<62%.易损洞窟和连阴雨天气应作为环境监测重点关注对象.研究成果对降雨天气莫高窟壁画劣化风险防范和旅游管理具有重要的科学价值和应用价值.

Dunhuang Mogao Grottoes, an important Buddhist cultural site along the Silk Road, is famous for its exquisite murals and statues. However, the change of humidity caused by rainfall in caves is very easy to cause salt diseases in murals. Through environmental monitoring experiments, the characteristics and potential effects of cave humidity change under different levels of rainfall were analyzed, and the risk prevention measures and suggestions were put forward. The results show that the variation of cave humidity presents three stages of ascending, maintaining and descending under different levels of rainfall. The rainfall in the early period increases the humidity rapidly, and the rainfall in the late period decreases the humidity slowly. The retention time of high humidity increases with the increase of rainfall level and rainfall frequency. During rainfall, the water vapor gradient is the main driving force of water vapor exchange. The wet air in the atmosphere diffuses into the cave when a_air>a_cave, and the humidity of the cave increases. The wet air inside the cave flows outside when a_air<a_cave, and the humidity decrease gradually. The order of cave humidity and relative humidity over 62% for the duration is semi-closed cave>closed cave, small cave>large cave. In order to prevent the increase of cave humidity to activate the mural salt damage, it is recommended to implement cave environment control when a_air=a_cave, and the control condition is RH<62%. The environmental monitoring should focus on the vulnerable caves and the continuously rainy weather. The research results have important scientific and application value for the prevention of risk of murals deterioration and the tourism management in rainy weather.

引言
1 环境监测试验
2 环境监测结果及分析
3 降雨天气壁画劣化风险防范措施及建议
4 结论

图1 敦煌莫高窟地理位置<br/>Fig.1 Geographical location of Dunhuang Mogao Grottoes

图1 敦煌莫高窟地理位置
Fig.1 Geographical location of Dunhuang Mogao Grottoes

图2 代表性洞窟
Fig.2 Representative caves

图3 中雨天气绝对湿度变化<br/>Fig.3 Change of absolute humidity during moderate rainfall

图3 中雨天气绝对湿度变化
Fig.3 Change of absolute humidity during moderate rainfall

图4 大雨天气绝对湿度变化<br/>Fig.4 Change of absolute humidity during heavy rainfall

图4 大雨天气绝对湿度变化
Fig.4 Change of absolute humidity during heavy rainfall

图5 暴雨天气绝对湿度变化<br/>Fig.5 Change of absolute humidity during rainstorm

图5 暴雨天气绝对湿度变化
Fig.5 Change of absolute humidity during rainstorm

图6 中雨天气相对湿度变化<br/>Fig.6 Change of relative humidity during moderate rainfall

图6 中雨天气相对湿度变化
Fig.6 Change of relative humidity during moderate rainfall

图7 大雨天气相对湿度变化<br/>Fig.7 Change of relative humidity during heavy rainfall

图7 大雨天气相对湿度变化
Fig.7 Change of relative humidity during heavy rainfall

图8 暴雨天气相对湿度变化<br/>Fig.8 Change of relative humidity during rainstorm

图8 暴雨天气相对湿度变化
Fig.8 Change of relative humidity during rainstorm

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备注

引言

1 环境监测试验

2 环境监测结果及分析

3 降雨天气壁画劣化风险防范措施及建议

4 结论

期刊信息