福建仙云洞空气CO2浓度的空间分布及影响因素  

Spatial Distribution Characteristics and Influence Factors of Cave Air CO_2 Concentration in Xian Yun Cave,Fujian,China

作　　者：王欢 曹奇[1,2] 李苗发[1,2] 王芳 雷国良 蔡炳贵[1,2,3] WANG Huan;CAO Qi;LI Miaofa;WANG Fang;LEI Guoliang;CAI Binggui(School of Geological Sciences,Fujian Normal University,Fuzhou 350007,China;State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province,Fujian Normal University,Fuzhou 350007,China;Institute of Geography,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]福建师范大学湿润亚热带山地生态国家重点实验室培育基地,福州350007 [3]福建师范大学地理研究所,福州350007

出　　处：《亚热带资源与环境学报》2018年第4期34-40,共7页Journal of Subtropical Resources and Environment

基　　金：国家自然科学基金资助项目(41661144021);福建省科技厅自然科学基金项目(2015R1034-8);福建师范大学校创新团队项目(IRTL1705)

摘　　要：洞穴CO_2浓度是影响洞穴次生化学沉积物沉积和溶蚀的重要因素之一,洞穴CO_2浓度与洞内外空气交换、裂隙流(滴)水以及洞穴空间形态等因素有关。因此,洞穴空气CO_2空间分布特征及其调控因素不仅是洞穴古气候重建研究的基础,同时也是洞穴旅游开发设计和洞穴资源保护的基础。对福建仙云洞的整个洞穴系统的CO_2浓度、温度进行了系统的野外现场测试,获得该洞穴夏季CO_2浓度的空间分布特征,结合洞穴结构、地下河分布等要素初步分析了夏季仙云洞洞穴空气CO_2浓度空间分布的主要影响因素及其对古气候重建和洞穴旅游开发的指示意义。结果表明:(1)夏季洞穴空气CO_2浓度变化介于400～2 800 u L·L-1,近洞口洞道、北洞和南洞之间空间差异显著,主要受洞穴结构特征和裂隙水分布控制;(2)近洞口(0～200 m)洞道宽大,总体倾斜向下,受洞穴内外空气交换的影响,CO_2浓度低,自洞口约400 u L·L-1逐渐增高到约550 uL·L-1,温度则快速下降。在距洞口约200 m,洞穴分叉,进入南北2个支洞系统后,CO_2浓度快速上升,但南北2个支洞系统CO_2浓度变化特征迥异;(3)北洞CO_2浓度相对较低,介于400～2 000 u L·L-1之间变化,不同洞道之间波动幅度大,这与北洞多变的洞道形状、时断时续的地下河以及不均匀的裂隙水分布有关,在部分裂隙水发育的洞道CO_2浓度异常增高,而在通风较好的平直洞道以及无裂隙水发育的地下河洞道CO_2浓度异常降低;(4)南洞则非常稳定,CO_2基本维持在2 250 u L·L-1左右,除了相对封闭且裂隙水发育的田园洞厅浓度稍高;(5)南洞相对封闭的洞穴环境,其石笋较北洞更适合开展古温度和古环境的重建工作;北洞更适合进行旅游开发活动。A survey is carried out to get the spatial distribution characteristics of the summer CO2concentration and temperature in air of Xian Yun Cave,Longyan.Its main influencing factors are discussed and some results are reached:(1)the summer cave CO2concentration,ranging from 400 to 2800uL·L^-1,shows significant differences among different tunnels.In general,the CO2distribution,in terms of the overall characteristics of the cave structure,can be divided into three parts:tunnels near cave entrance,northern cave and southern cave;(2)the contents of CO2are low at the tunnels near the cave entrance(0-200m)which is wide in cross section,and straight downward with a slope of around30°.The CO2contents raise gradually from 400uL·L^-1 to about 550uL·L^-1.This trend is a result from air exchange between air inside the cave and atmosphere outside.At about200meters away from the entrance,the cave branch into several tunnels,named southern cave and northern cave.Then,the CO2concentrations increase abruptly;(3)CO2concentration in northern cave is a little lower compared to those in southern.The values varied among 400-2000uL·L^-1,with large amplication in different tunnels during to complex tunnel structure and uneven distribution of infilter flowes and underground river.In some closed tunnels,where especially in rich of karst infilter flow,the CO2concentration increase abnormally.Conversely,whereas in straightness tunnel with well ventilation and in underground stream channel free of infilter flow,CO2concentration is abruptly decrease;(4)CO2concentration in the southern cave is stable at about 2250uL·L^-1 with little fluctuation,except for the Hall Tianyuan,where CO2concentration is slightly higher during to abundant of infilter flowes and relatively closed chamber;(5)The relatively closed cave environment in southern cave is more suitable for the reconstruction of paleotemperature and paleoenvironment than the stalagmite.However,northern cave is more suitable for tourism development activities.

关 键 词：CO2浓度 空间分布 仙云洞 福建 

分 类 号：P9[天文地球—自然地理学]