Spatial and temporal distribution characteristics of pCO2 and CO2 evasion in karst rivers under the influence of urbanization

Abstract

Surface rivers play an essential role in the carbon cycle processes in karst regions; however, less attention has been given to CO 2 emissions from karst rivers under the in uence of urbanization. In this study, we investigated CO 2 partial pressures (pCO 2 ) and degassing in a typical karst river (Nanming River and its tributaries) affected by urbanization in southwest China. Field sampling and measurements were conducted in the area from July 2021 to March 2022 in an attempt to determine the effect of urbanization on riverine pCO 2 and CO 2 degassing. The results showed that the average values pCO 2 of the Nanming River mainstream in the wet season, dry season and at season were 1975.77 ± 714.45