Gaoyuan qixiang (Aug 2023)
The Variation Characteristics of Temperature and Precipitation in Mogao Grottoes of Dunhuang in Recent 30 Years
Abstract
The site of the Dunhuang Mogao Grottoes is situated in a climate zone that is characterized by a high-temperature difference and scarce precipitation.Variations in air temperature and precipitation may bring negative impacts to the supports， floors， and paints of the statues or murals， and thus the degradation and disease of the relics.It is therefore necessary to analyze the causes of mural deterioration and study the characteristics of temperature and precipitation variations in order to protect the murals.The measured air temperature and precipitation at the top of the grottoes over the past 30 years at different time scales （inter-annual， seasonal， and monthly） were analyzed， and the dry climate in the key protection area of Dunhuang Mogao Grottoes and its impact on cultural relics were also discussed.The results indicated that the average air temperature has increased significantly［0.46 °C·（10a）-1］ and that precipitation has also increased significantly［2.21 mm·（10a）-1］in the past 30 years.However， the interannual variability of precipitation was substantial， and the increase was negligible； consequently， the warming and drying trend is evident in the region.The air temperature in spring， summer， autumn， and winter all exhibited an upward trend， with respective growth rates of 0.73 °C·（10a）-1， 0.44 °C·（10a）-1， 0.32 °C·（10a）-1， and 0.26 °C·（10a）-1.The spring and summer temperature increases were primarily responsible for the temperature increase.Spring and summer precipitation increased （1.48 mm·（10a）-1 and 0.85 mm·（10a）-1， respectively）， while autumn precipitation decreased ［-0.29 mm·（10a）-1］ and winter precipitation was relatively stable.On the monthly scale， the highest values of air temperature and precipitation occurring in July and the lowest values occurring in January.Overall， the warm and arid climate of the Dunhuang Mogao Grottos is conducive to the preservation of cultural artifacts.
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