摘要
岩溶地区的复杂性加大了洞穴滴水研究的难度,土壤厚度状况对洞穴滴水水文类型和水化学特征有重要影响。本研究对合肥市清江洞内6个滴水点开展了一个水文年监测,采用Smart-Friendrich分类系统进行滴水分类,探讨土壤厚度对水文、水化学特征及先期方解石沉淀(PCP)的影响。结果表明:(1)清江洞滴水点可分为渗流、包气带流和季节流三种滴水类型,滴速与土壤含水量密切相关,呈现出雨季大旱季小的变化特征,上覆土壤较薄的渗流类滴水点滴速全年稳定性较好,不易断流;(2)滴水水化学季节变化明显,其中二氧化碳分压(pCO_(2))、电导率(EC)、Ca^(2+)存在较明显的空间差异,渗流类滴水点因上覆土壤较薄而数值最小,另外两类滴水点因上覆土壤较厚,水化学数值和变幅较大;(3)滴水点稳定碳同位素(δ^(13)C_(DIC))与水化学特征变化类似,渗流类滴水点因上覆土壤较薄,其δ^(13)C_(DIC)更偏正,包气带流和季节流类滴水点δ^(13)C_(DIC)则相反;(4)土壤厚度影响滴水点的干湿状况和水化学特征,进而也对PCP过程产生重要影响。这些发现证明了土壤厚度是影响滴水水文、水化学和δ^(13)C_(DIC)的重要因素。
The complexity of karst areas has increased the difficulty in studying cave drip water,with soil thickness significantly influencing both hydrological and hydrochemical.This study monitored six drip sites in Qingjiang Cave(Zunyi,China)over one hydrological year,classifying drip types using the Smart-Friendrich system to investigate the effects of soil thickness on hydrology,hydrochemistry,and prior calcite precipitation(PCP).The results showed that:(1)The drip rate in Qingjiang Cave was closely associated with the soil water content,exhibiting higher rates during the rainy season and lower rates during the dry season.Moreover,the drips can be classified into three types of flow:seepage,vadose,and seasonal flow.(2)The hydrochemistry of drip water displayed pronounced seasonal variations,and partial pressure of carbon dioxide(pCO_(2)),electrical conductivity(EC),and Ca^(2+)concentrations exhibited remarkable spatial heterogeneity.Notably,seepage flows consistently showed the lowest values,whereas vadose and seasonal flows exhibited higher concentrations with substantially greater variation amplitudes.(3)The stable carbon isotopes(δ^(13)C_(DIC))and hydrochemical characteristics showed similar variation patterns in drip waters.Seepage flow sites with thin soil cover displayed more positiveδ^(13)C_(DIC) values,while vadose and seasonal flows exhibited the opposite trend(more negative values).(4)Soil thickness governed drip-site hydrology and chemical properties,thereby directly affecting PCP.In conclusion,these findings demonstrated that soil thickness served as a critical regulator of drip water hydrological processes,hydrochemical composition,andδ^(13)C_(DIC) variability.
作者
黄正周
胡运迪
周忠发
胡德勇
赵敏
张宇超
范宏岱
王登超
尚运
张晴
HUANG Zhengzhou;HU Yundi;ZHOU Zhongfa;HU Deyong;ZHAO Min;ZHANG Yuchao;FAN Hongdai;WANG Dengchao;SHANG Yun;Zhang Qing(School of Geography and Environmental Sciences,Guizhou Normal University,Guiyang 550025,China;State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province,Guizhou Normal University,Guiyang 550025,China;105 Geological Brigade,Guizhou Bureau of Geology and Mineral Resources Exploration and Development,Guiyang 550018,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China)
出处
《生态学报》
北大核心
2025年第15期7179-7190,共12页
Acta Ecologica Sinica
基金
国家自然科学基金面上项目(42072278)
贵州省科技计划项目(黔科合基础ZK[2022]一般306)。
关键词
土壤厚度
滴水
水文类型
水化学
元素/Ca比值
soil thickness
drip water
hydrological types
hydrochemical characteristics
element/Ca ratio
