川东北楼房洞洞穴环境时空变化与影响因素

Spatial and Temporal Variation of Environments and Influencing Factors in Loufang Cave, Northeast of Sichuan Province

基于2011年8月-2012年6月的实地监测数据，文章报道了川东北楼房洞溶洞系统气温、相对湿度（RH）、CO2体积分数、水体电导率（EC）和pH值等为期近1年的监测结果，并对其影响因素进行了分析。结果显示楼房洞洞穴系统环境存在明显的空间变化和季节变化：1）洞穴内的气温变化幅度比洞穴外小，洞穴内夏季气温比冬季高出3～5℃；2）在洞穴内，相对湿度在地下河附近小于在水池附近，显示了地下河对洞穴环境的显著影响；3）洞内监测点SLPB和QCMY处的相对湿度与空气温度出现明显相反的变化趋势，反映主要受气温控制的特点；4）雨季期间SLPB、QCMY和LZLY处的CO2体积分数出现峰值，是较强的生物呼吸作用、“泵”效应和较弱的通风效应等因素综合影响的结果；5）pH值的变化趋势在洞穴内外各监测点一致，原因可能是夏秋季节基岩溶蚀较强所致。6）洞内各监测点的EC值也是夏秋季节高于冬春季节，反映了气候变化导致的化学溶蚀作用可能是影响离子含量的主要因素。

Cave monitoring is important for explaining climate proxies in speleothems, therefore Karst Climatology is one of the important aspects of cave monitoring. Four sites were chosen to be monitored inside or outside Loufang Cave, Northeast of Sichuan Province： No.1 monitoring site named SLPB which is the farthest one away from the entrance of the cave with a good enclosed enviorment, it’s also an entrance of underground river cavern with perennial running water;No.2 monitoring site named QCMY which is near the ponor, located at the end of underground river;No.3 monitoring site named LZLY beside a pool, which is at a distance from the entrance of the cave about 45 meters;No.4 monitoring site named HS is outside the cave, which is at a distance from the entrance of the cave about 45 meters. Through a 11-months （from August 2011 to June 2012） monitoring on air temperature, Relative Humidity （RH）, CO2 concentration, Electronic Conductivity （EC） and pH value of water in those four sites, this paper reports monitoring results and analyzes its influencing factors, which show that there’s an obvious temporal and spatial variation of cave environments. The results show that：1） Variation in air temperature inside the cave is smaller than that outside, the temperature in summer is 3～5℃higher than that in winter inside the cave. 2） Relative humidity of the site inside the cave which is near the underground river is less than that near the pool, showing that the underground river has a significant impact on the cave environments;3） As compared with the air temperature, the relative humidity of Loufang Cave in SLPB, QCMY has an opposite trend, showing that it is mainly controlled by temperature. 4） During the rainy season, the CO2 concentration appeares one peak in SLPB, QCMY and LZLY, that may be strongly influenced by “pump” effect, ventilation effect and weaker biological respiration, etc. 5） Both inside and outside the cave, the variation tendency of pH values in each monitoring point is consistent, and the pH values in summer and fall are higher than those in winter and spring, they may be caused by the rock erosion in summer and fall season;6） In summer and fall, EC values of each monitoring point in the cave are also higher than those in winter and spring, showing that the chemical corrosion effect caused by climate change may be the main factor influencing the ion content.