短时间高强度旅游活动下洞穴空气环境变化特征及其影响因素分析——以绥阳大风洞为例

文章通过对大风洞2017年、2018年十一"黄金周"洞内外温度、CO_2浓度、相对湿度、游客量等为期7天的连续监测,并运用系统分析方法对各个监测指标进行综合分析。结果表明:(1)监测期间,受洞穴通风效应和游客量等的影响,大风洞空气环境要素(温度、湿度、CO_2浓度)呈现明显昼夜变化,表现为白昼夜晚;(2)洞道结构对洞穴空气环境空间变化具有重要影响,表现为神泉玉露洞道结构较夜明珠更为复杂,在2017年、2018年的温度、湿度、CO_2浓度等均要比夜明珠的高;(3)洞外空气环境变化对洞穴通风效应具有重要的影响,表现为降雨导致洞外温度、湿度降低,虚拟温差发生改变,促使气流方向由限制性通风模式向积极性通风模式转变;(4)受气候及游客因素影响,2017年洞内温度、CO_2浓度的昼夜变化特征较2018年更明显,且当游客产生的CO_2浓度大于洞穴空气环境的自净能力时,CO_2会出现累积效应,进而影响洞穴旅游景观及洞穴环境的舒适性,建议景区在进行旅游活动时要充分考虑短时间尺度游客人数高峰期对CO_2的影响及岩溶景观的合理保护。

Characteristics of Air Environment Changes in Caves under Short-term and High Intensive Tourism Activities and Its Influence Factors: A Case Study of the Dafeng Cave in the Suiyang County

Through the continuous monitoring of temperature, CO₂ concentration, relative humidity and tourist volume in the first week of October in years 2017 and 2018, this study collected and analyzed above monitoring data systematically. The results showed that: (1) during the monitoring period, due to the ventilation effect of the cave and the amount of tourists, the air environment factors (temperature, humidity, CO₂ concentration) of the Dafeng Cave showed the obvious diurnal change of day > night; (2) the cave structure has important influences on the spatial change of air environment factors of the cave, for example, temperature, humidity and CO₂ concentration of the Shenquanyulu site were higher than those of the Yemingzhu site since the structure of the Shenquanyulu site is more complicated than that of the Yemingzhu site; (3) the change of air environment outside the cave influence significantly on the ventilation effect of the cave, for example, the airflow in the cave changed from the restrictive ventilation mode to the active ventilation mode during rainfalls, which reduced temperature and humidity outside the cave; (4) as the result of climate and tourist number factors, diurnal variations of temperature and CO₂ concentration in the cave were more severe in 2017 than in 2018. When CO₂ generated by tourists exceeds the self-purification capacity of the cave, CO₂ will be accumulated in the cave and the cave tourism landscape and the comfort of the cave environment will be deteriorated. Therefore, it is recommended that impacts of tourism activities during the peak period should be considered carefully for protecting the karst landscape of the scenic spot.