摘要
2012-05-08—17期间,漓江先后出现3次洪水,在洪水期间对漓江进行了高频率昼夜监测。发现洪水过程中不同阶段岩溶碳汇具有不同的变化特征,研究表明:Ⅰ和Ⅴ阶段的河流水化学由于基本未受洪水影响,pH、水温和PCO2具有明显的昼夜变化特征,EC、流量和HCO3-则相对较稳定;Ⅱ、Ⅲ和Ⅳ阶段由于洪水的影响出现了不同的变化特征,其中Ⅳ阶段由于雨后碳酸盐岩的溶解,降雨主要分布于岩溶区及降雨量较小等因素导致Ⅳ阶段流量与HCO3-为正相关,与Ⅱ、Ⅲ阶段相反。利用水化学-径流法计算洪水过程中的碳汇量,碳汇与流量和HCO3-的相关系数分别是0.87和0.33。本次洪水监测期间的碳汇通量为3 491.06 t C,其中洪水过程中的碳汇量是洪水前的4.52倍。
Floods appear successively three times in Li River from 8 to 17 of May in 2012.There is high-frequency diurnal monitoring in flood process.It is found that the carbon sink at different stages has different characteristics during flood process.The results show that river hydrochemistry of Stage Ⅰ and Ⅴ is not influenced by flood,so the pH value,water temperature,EC（electrical conductivity） and PCO2（carbon dioxide partial pressure） have obvious diurnal variation characteristics,while EC,flow and HCO-3 is relatively stable.Due to flood influence,there are different characteristics at Stage Ⅱ,Ⅲ and Ⅳ,where the dissolution of carbonate rock after rain,rainfall is mainly distributed in karst area.Less precipitation and other factors lead to positive correlation between flow and HCO-3 in Stage Ⅳ,contrary to Stage Ⅱ and Ⅲ.The amount of carbon sink is calculated by hydrochemistry-runoff method in flood.It is found that there are good linear relationships between carbon sink and flow.Between carbon sink and HCO-3,the correlation coefficients are 0.87 and 0.33 respectively.Carbon sink flux is 3 491.06 t C during the monitoring of flood,where the carbon sink before flood is 4.52 times higher than that in flood.It is necessary to strengthen carbon sink monitoring in karst area flood.
出处
《桂林理工大学学报》
CAS
北大核心
2012年第4期512-518,共7页
Journal of Guilin University of Technology
基金
中国地质调查局项目(1212011087122
1212011087119)
中国地质科学院基本科研业务费项目(2010-SYS-15)
广西自然科学基金项目(桂科自0991249)
关键词
岩溶
洪水
碳汇
漓江
karst
flood
carbon sink
Li River
