梅州山地化学风化过程及其碳汇效应  

Chemical Weathering Processes and CO_2 Consumption in Mountainous and Hilly Areas around Meizhou City,China

作　　者：郑伟[1] 林培松[1] 高全洲[1,2] 

机构地区：[1]中山大学地理科学与规划学院,广东省城市化与地理环境空间模拟重点实验室,广东广州510275 [2]广东省地质过程与矿产资源探查重点实验室,广东广州510275

出　　处：《山地学报》2016年第5期571-579,共9页Mountain Research

基　　金：国家自然科学基金项目(41340019,41071054);广东省自然科学基金重点项目(2014A030311003)~~

摘　　要：根据梅州山地丘陵区地表径流的化学组成,应用物质平衡法和扣除法进行化学风化过程中CO_2吸收通量的估算。结果表明:在硅酸盐岩分布面积为84%的湿热梅州山地丘陵区,河水总溶解性物质含量均值为41.58 mg/L,远低于世界河流平均值。河水离子组成以Ca^(2+)、HCO_3^-以及溶解性硅(DSi)为主。岩石化学风化过程和大气降水作用对流域水化学特征的影响最为显著,其中硅酸盐岩的风化作用对水体离子的贡献率为81.46%~86.03%;大气降水对水体离子的贡献率为10.86%;碳酸盐矿物化学风化作用的贡献仅为5%左右。岩石化学风化过程对大气CO_2的吸收通量为(3.46~5.26)×10~5mol/(km^2·a),高于全球平均值2.46×10~5mol/(km^2·a),说明北半球亚热带季风山区的表生地质作用构成全球碳汇的一个重要组成部分。Based on the chemical compositions of runoff in the Meijiang River system around Meizhou City, Guang dong Province, China where mountain and hilly areas dominated. Consumption flux CO2 in the chemical weathering process was estimated using material balance method and deduction method. The results demonstrated that the average concentration of total dissolved solids in the Meijiang River system around Meizhou City, where silicate rock areas account for about 84%, is 41.58 mg/L, and that the mineralization of the Meijiang River water is much lower than the averages value of rivers worldwide （100 mg/L）. Ca2＋ , HCO3 and dissolved Si are the main ion in the river water. The chemical weathering process of rocks and atmospheric precipitation significantly influenced the chemical composition of water in the Meijiang River system. The ion contribution rate from the chemical weathering of silicate mineral, atmospheric precipitation and carbonate mineral weathering is 81.46% - 86. 03% , 10.86% and 5% , respectively. The consumption flux CO2 in the rock chemical weathering processes is （3.46 -5.26） × 10^5mol/（ km2 · a）, which is higher than the global average value of 2.46 × 10^5moL/（ km2 · a）, implying that the surface geological processes in humid monsoon subtropical mountainous areas of the Northern Hemisphere constitutes an important component of the global carbon sequestration.

关 键 词：化学风化 碳汇 侵蚀介质 硅酸盐矿物 山地丘陵 

分 类 号：P512.1[天文地球—地质学] P595