Microclimate characteristics and tourist carrying capacity of Phong Nha cave, Phong Nha - Ke Bang National Park

Abstract

Cave tourist carrying capacity refers to the maximum number of visitors that a cave can accommodate at a given time without causing irreversible damage to the natural environment. In this study, the tourist carrying capacity of Phong Nha Cave was determined for the first time based on microclimatic indicators using the Lobo method. Air temperature, relative humidity (RH), and carbon dioxide (CO₂) concentrations inside Phong Nha Cave were regularly monitored during the summer and winter of 2023. In addition, continuous temperature measurements were conducted at five-minute intervals. The results from both regular and continuous monitoring indicate that the total temperature recovery time in Phong Nha Cave was 497 minutes in summer and 318 minutes in winter. Based on three different tourism scenarios, the maximum allowable number of visitors was estimated at 1,260; 2,520; and 3,780 people per day, respectively. The average visitor stay time at Dong Tien area was 7.8 minutes in summer and 12.7 minutes in winter. These findings provide valuable scientific evidence to support the management and conservation of Phong Nha - Ke Bang National Park and are recommended for application in assessing tourist carrying capacity in other show caves across Viet Nam.