Microclimatic Monitoring of Tourist Caves in Minas Gerais: Preliminary Analysis of Temperature and Relative Humidity Data in Seven Caves of the Cavernas do Peruaçu National Park

Abstract

In Brazil, the first studies related to cave climate monitoring are from the 1960s and were characterized by low sample density (periods of less than one year) and isolated temperature and humidity measurements in caves open to tourist visitation. The most recent research started to incorporate new methods and technologies, such as, for example, the use of automatic data recorders. The Microclimatic Monitoring of Tourist Caves in Minas Gerais Project intends to carry out long-term monitoring, scheduled for 6 years. This manuscript presented the results of the first phase of the project, comprising the monitoring carried out between 2017 and 2019 in seven caves of the Parque Nacional Cavernas do Peruaçu. For this analysis, 41 automated meters were installed inside and close to entrance to the caves, which recorded and stored temperature and humidity data every 10 minutes. The results show that the Lapa Bonita cave has the lowest average temperature (20.79°C) and Lapa dos Desenhos, the highest average temperature (24.07°C). Regarding the relative humidity of the air, Lapa dos Desenhos presents the lowest values, with an average of 62.56% and Lapa Bonita the highest, with an average of 85.28% among all the caves evaluated in the period studied. The survey also found that, among all the caves evaluated, Lapa Bonita is the one that show the smallest variations in these parameters, with a standard deviation of 0.54 for temperature and 9.96 for humidity. The knowledge of the microclimate characteristics of each cave obtained with the monitoring data will assist the management of the national park to adopt new limits concerning the load capacity currently established for each of these attractions.