[Objective]Carbonate rocks have a significant carbon sink effect in water cycle.Since karst landforms are widely distributed in China,research on the potential of karst carbon sinks plays an important role in formula-ting regional strategies for increasing carbon sinks.[Methods]In this study,groundwater monitoring points in Hu-bei Province,which is located in the karst area of Southwest China,were selected.Quantitative calculations and method comparisons were performed based on the hydrochemical runoff method and the infiltration-equilibrium chemistry method.The spatial pattern and magnitude of karst carbon sinks in the hilly mountains of Hubei Province from 2019 to 2021 were evaluated via ArcGIS spatial analysis techniques.Additionally,the most suitable method for estimating karst carbon sinks at the regional scale were explored,the comprehensive analysis of the drivers of karst carbon sinks was performed,and the potential for increasing sinks were explored.[Results]The results showed that:(1)the intensity of carbon sinks estimated by the infiltration-equilibrium chemistry method were 2020＞2019＞2021.The total amount of karst carbon sinks in wet year(2020)was approximately 6 times of that in dry year(2019).The average annual carbon sink intensity in the three years was 12.84 t/(km2·a)and the annual total amount of carbon reached 163.89x 104 t/a;(2)the infiltration-equilibrium chemistry method was more accu-rate in calculation results and simpler in data acquisition than the hydrochemical runoff method,and had a certain universality at both large and small spatial scales;(3)the change in carbon sinks was highly dynamic.The extent of changes in carbon sinks under climate change was mainly determined by runoff depth,with the intensity of car-bon sinks increasing with runoff depth,while land use regulated the intensity of carbon sinks in karst processes;and(4)the karstification is strong in southwestern Hubei Province,so a pilot field of karst carbon sinks could be established within the area to quantitatively evaluate artificial interventions to increase carbon sinks.[Conclusion]This study not only provides an accurate and easy-to-use method for estimating karst carbon sinks,but also deter-mines the magnitude and spatial pattern of karst carbon sinks in Hubei Province and figures out the coupling effect of the driving factors of carbon sink intensity,which demonstrates the complexity and anthropogenic control lability of karst carbon sinks.The results of this study provides a reliable scientific basis for the formulation of environmen-tal protection policies and artificial sink increase measures.
关键词
岩溶碳汇/水化学径流法/入渗-平衡化学法/ArcGIS空间分析/驱动因子/湖北省
Key words
karst carbon sink/method of solute load/method of infiltration-equilibrium chemistry/ArcGIS spatial analysis/driving factor/Hubei Province
维普
万方数据