Analysis on the relationship between climatic and environmental factors in karst caves: An example from Zhijin Cave of Guizhou Province

Zhijin Cave as a tourist cave with a poorly closed environment connects with the outside via cave tunnel and many shafts and fractures. Due to the change of atmospheric environment and tourist volume fluctuation in summer and autumn, the CO2 concentration and humidity in the cave are usually higher than that of spring and winter. The correlation statistical analysis of the cave CO2 concentration, air pressure, air temperature and humidity with data obtained in January 2015 to January 2016 was performed. Temperature and CO2 concentration showed a negative correlation, and the correlation coefficients in summer and autumn were -0.72876 and -0.65616, respectively. However, in spring and winter the temperature and CO2 concentration was positively correlated, and the correlation coefficients of the two quarter were 0.85452 and 0.93846, respectively. Except for the relationship between humidity and temperature, the fitting degrees between the other environmental factors on the basis of SINE function fitting are comparatively high, which fall in the range of 0.6-0.8. According to the analytical results, the relationship between climatic and environmental factors is believed to be heavily impacted by the seasonal tunnel air exchange, atmospheric precipitation, cave water, overlying soil CO2, tourists who visit the cave, cave lightening facilities and etc.