西南喀斯特地区水体溶解无机碳时空分布特征及其来源分析

Spatial-temporal Distribution and Sources of Dissolved Inorganic Carbon in Karst Water,Southwest China

碳循环是地球主要物质循环之一,对全球气候变化与人类发展具有重要影响。本文梳理了近年来嘉陵江水系、乌江水系、赤水河水系及西江水系溶解无机碳的相关研究成果,对西南喀斯特地区水体溶解无机碳(DIC)与碳同位素(δ^(13)C_(DIC))的时空分布特征、影响因素及其来源进行全域性视角分析,并得出以下结论:(1)西南喀斯特地区水体DIC含量与δ^(13)C_(DIC)值在各水系之间存在差异性,具有显著时空分布特征,其中赤水河水系DIC含量(2.79mmol/L)与δ^(13)C_(DIC)值(-8.15‰)均最高,西江水系DIC含量(1.95mmol/L)与δ^(13)C_(DIC)值(-10.6‰)最低;(2)该地区DIC含量变化受到碳酸盐岩化学风化、气候变化及人类活动等因素的综合影响;(3)流域内DIC主要来源于碳酸盐岩风化与土壤CO_(2)。研究结果有助于推动河流流域溶解无机碳变化的研究,为我国水体碳循环研究提供理论基础。

The carbon cycle constitutes one of the major occurring material cycles,with a large influence on human development and global climate change.This paper reviews recent research on dissolved inorganic carbon(DIC)in the Jialing River basin,Wujiang River basin,Chishui River basin,and Xijiang River basin.It provides a comprehensive analysis from a regional perspective on the spatiotemporal distribution,influencing factors,and sources of DIC and carbon isotopes(δ^(13)C_(DIC))in the water bodies ofthe southwestern karst region.The conclusions are as follows:(1)There were variations in DIC concentration and δ^(13)C_(DIC) values among the different water systems,with notable spatiotemporal distribution.The Chishui River basin exhibited the highest DIC concentration(2.79 mmol/L)and δ^(13)C_(DIC) value(-8.1‰),while the Xijiang River basin had the lowest DIC concentration(1.95 mmol/L)and δ^(13)C_(DIC) value(-10.6‰).(2)DIC concentration changes in the region were influenced by a combination of factors,including carbonate rock chemical weathering,climate change,and human activities.(3)DIC in the watershed is primarily derived from carbonate rock weathering and soil CO_(2).These research results contribute to advancing the study of DIC variations in river basins and provide a theoretical foundation for carbon cycling in water bodies in China.