Variation in cave air temperature and humidity and their driving mechanisms in Shihua Cave,Beijing
In cave environments,the temperature and relative humidity are considered the important factors in the formation of stalagmites.In this study,we introduced a contribution of 43-month duration monitoring records with hourly resolution on temperature and relative humidity,within the Shihua Cave in Beijing,aiming to discern the interplay between these environmental variables and understand their interrelation with the cave dynamics.The observation results are as follows:(1)Cave temperature and relative humidity show the characteristics of low in winter and spring and high in summer and autumn.Notably,the temperature dynamics within the cave exhibited a temporal lag behind surface temperature changes,ranging between 1 to 3 months.This lag contained a gradual response to warming trends and a relatively fast response to cooling trends.Additionally,the response characteristics differ across various monitoring points.In the cold season,both the temperature and humidity at the XHT(Xiuhuatai)and XMG(Xiaomogu)displayed a declining trend and a notable positive correlation.In contrast,the relative humidity levels at the PL(Panlong)remained essentially saturated throughout the year and demonstrated no significant correlation with temperature fluctuations.(2)There are notable seasonal differences in the daily fluctuations of temperature and relative humidity in the cave.In the cold season,the temperature patterns at the PL and XMG monitoring points exhibit a stark contrast to the daily temperature variations on the surface and the relative humidity levels at the XHT and XMG points correspond to the daily fluctuations in surface relative humidity,whereas the XHT points align with the surface temperature trends.In the warm season,the temperature fluctuations at the cave's monitoring points mirror the daily temperature changes on the surface.The significant spatial distribution pattern of temperature and relative humidity in the cave reflects the seasonal differences in airflow activity,influenced by the unique"floor-type"structure of the Shihua Cave,and tourism activities.Airflow activity in the winter mainly affects temperature and humidity changes in the cave.During peak periods and at the attraction,the influence of tourism activities is significant.The findings of this study advanced our understanding of airflow dynamics under the cave setting and established a solid foundation for the cave stalagmite deposition interpretations and their paleoclimate mechanism.Furthermore,this research can serve as valuable guidance for the conservation of tourist cave landscapes.
in-cave temperature and relative humidityvariation characteristicsairflow activityinfluencing factorsShihua Cave in Beijing
万方数据
维普
