Calculation of atmospheric CO_2 sink formed in karst progresses of the karst divided regions in China

In order to calculate the atmospheric CO2 sink formed in karst processes,the karst area of China can be divided into four types of karst regions-south China karst region,north China karst region,the Tibet plateau karst region and the buried karst region.The area of the above regions is 564 800 km2,325 800 km2,556 000 km2 and 2 001 000 km2 respectively.The karst water flow and the karstification degree in each region are different.Solution rate of the carbonate rocks in south China karst region is much bigger than that in the other three karst regions.Based on the data from recent geologic survey and statistics of the other research results,the atmospheric CO2 sinks formed in karst processes of the above-mentioned four karst regions are estimated as 1 909.9×104 tCO2/a,600.5×104 tCO2/a,580.1×104 tCO2/a and 608.6×104 tCO2/a respectively.Therefore,the total atmospheric CO2 sink formed in karst processes of China is 3 699.1×104 tCO2/a.This estimated result is more comprehensively to represent the present quantity of atmospheric CO2 sink formed in the inorganic carbon-water-calcium cycle in whole karst areas in China than that of the former other estimations.