本文以水房泉表层岩溶泉域为例,通过CDTP300多参数自动水质监测仪提供的年际连续的电导率、水温、水位,利用岩溶水化学-径流量方法计算出水房泉连续两年各月的CO2吸收量和年吸收总量。计算结果显示水房泉各月CO2吸收量中6、7、8三个月吸收量较大,1、2、12月吸收量均较小;年最大CO2吸收量出现在7月份,年中最小CO2吸收量出现在1月份。水房泉各月CO2吸收量同水房泉出口月径流量和月降雨量都有很好相关性,雨季吸收量远大于旱季吸收量。泉水HCO3-含量受到气温、降水、径流量和土壤CO2含量的综合影响,HCO3-含量的最高值与月CO2吸收量的最大值在时间上存在2个月的滞后现象。相对于较大流域碳汇的估算,以小流域为对象从短时间尺度计算碳汇更加精确,而且对于流域岩溶作用碳汇过程及其控制机理的深入揭示也是非常必要的。
The study mainly focus on the Shuifang epikarst spring basin.By using the multi-parameter instrument CDTP300,interannual continuous data of conductivity,water temperature and water level are got.Annual and monthly CO2 consumption in two years are calculated by means of karst hydrochemistry-discharge method.The result shows that CO2 consumption of Shuifang Spring is relatively high in June,July and August;while it's low in January,February and December.The maximum value of CO2 absorptive quantity appeared in July and the minimum in January.The result also shows that the monthly discharge of the Shuifang Spring and rainfall are intensively correlated with the CO2 consumption,and the CO2 consumption in rainy season is much larger than dry season.The bicarbonate concentration of the Shuifang Spring is influenced by air temperature,rainfall,discharge and soil CO2.There are two months time-delay between the biggest monthly CO2 consumption and the highest bicarbonate concentration.Through this study it is found that the estimate of carbon flux in small watersheds by hydrochemistry-discharge method is more accurate than large watersheds and it may give an effective method to the further research on carbon sink for karstification and its control mechanism in epikarst zone.