贵州织金洞洞穴CO_2的来源及其空间分布特征  

Source of cave CO_2 and its spatial attributive characteristics of Zhijin Cave in Guizhou Province

作　　者：张绍云[1,2] 周忠发[1,2] 张强[1,2] 谢雅婷[1,2] 

机构地区：[1]贵州师范大学中国南方喀斯特研究院,贵州贵阳550001 [2]贵州省喀斯特山地生态环境国家重点实验室培育基地,贵州贵阳550001

出　　处：《中国岩溶》2016年第3期307-313,共7页Carsologica Sinica

基　　金：国家自然科学基金地区项目"岩溶洞穴CO2迁移变化机制及对洞穴岩溶环境的影响研究"(41361081);贵州省科技计划"贵州省洞穴调查数据技术服务"(黔科合G字[2014]4004-2号);贵州省重大应用基础研究项目"喀斯特石漠化生态修复及生态经济系统优化调控研究-岩土类型格局"(黔科合JZ字[2014]200201)

摘　　要：为探索喀斯特高原峡谷地区高位旱洞内CO_2来源及其空间分布特征,于2015年1月至2015年7月按月实施定位监测,对贵州织金洞洞穴CO_2浓度和洞穴水、土壤CO_2浓度和土壤水以及大气降水、山顶泉水进行监测。结果表明:(1)织金洞上覆土壤CO_2浓度是大气CO_2浓度的11~17倍,是洞穴CO_2的4~7倍。织金洞洞内CO_2的来源,横向上主要来自于气流的交换、游客的呼吸作用;垂直方向上主要来自于洞穴上方延伸入基岩中植物根系的呼吸作用,洞穴上覆基岩溶隙、溶管中进入洞穴内的大气CO_2,地下河水脱气以及洞穴滴水碳酸钙的沉积释放的CO_2。(2)织金洞为多进口洞,C02浓度插值空间分布呈现两端低中间高的空间分布特征,同时在1 200×10^(-6)~1 400×10^(-6)高值区范围内出现800×10^(-6)~1 000×10^(-6)低值区特征。整体上,洞穴CO_2随着进、出洞口两端海拔向洞内升高而呈上升趋势,在洞穴中部灵霄殿达到最大值。(3)洞内水和洞外土壤水均为HCO_3^--Ca^(2+)型水,大气降水、山顶泉水为SO_4^(2-)-Ca^(2+)型水。在垂直迁移过程中,大气降水-山顶泉水-土壤水-洞穴水不同部位水中备化学成分(硬度、Ca^(2+)/Mg^(2+)、HCO^(3-)/SO_4^(2-)、P_(CO_2)、SIc)备不相同。In order to explore the source of cave CO2 and its spatial distribution in karst plateau gorge area, a monitoring program on monthly basis was conducted at Zhijin Cave, Guizhou province, from January to July in 2015 for the monitoring of CO2 concentrations in cave and soil, cave water, soil moisture, rainfall and in the spring water above the cave. The results show that. （1） CO2 concentration in the soil above Zhijin cave is 11 --17 times of atmospheric CO2, and 4--7 times of the cave CO2, respectively. The major sources of Zhijin cave CO2 come from air exchange and tourists respiration in horizontal direction; in vertical direction they are mainly from the respiration of plant root extending into the bedrock at the top of the cave, overlying cave foundation in karst fissure, soluble tubes entering inside the cave, the atmospheric CO2 ,and the freed CO2 due to the cave calcium carbonate deposition via groundwater degassing and dripping water in the cave. （2） Zhijin Cave is a multiline cave, the interpolation of space distribution of CO2 content showed characteristics of low ends and high in the middle, at the same time,the low value range of 800--1,000 ppm appears in the range of 1,200--1,400 ppm. In the whole cave, CO2 concentration tends to increase from both ends to the middle of the cave, along with an elevated altitude, which reaches a maximum value in Lingxiao Palace. （3） The groundwater in cave and soil water outside of the cave are both HCO3--Ca^2＋ type, while the atmos- pheric precipitation and spring water are SO4^2- --Ca^2＋ type. In the process of vertical migration, the chemical composition （hardness,Ca^2＋/Mg^2＋ , HCO3^-/SO4^2- ,PCO2 ,Sic） in different parts of water from rain-spring-soil water-cave water is different.

关 键 词：CO_2 水化学 空间差异 织金洞 

分 类 号：P463.23[天文地球—大气科学及气象学]