摘要
岩溶作用对气候、水文与土地利用等环境因子变化十分敏感。对比不同气候区岩溶作用的空间（土地利用的影响）及季节变化，有助于进一步揭示岩溶作用的短时间尺度效应。本文以泰国北碧赛要县普特热带岩溶峰丛谷地小流域为背景，利用标准溶蚀试片法研究不同土地利用区土下溶蚀量，分析了溶蚀速率的差异程度与影响因素，并与中国西南亚热带典型峰丛洼地区进行了对比。结果表明，空中（离地面1.5m高）年平均溶蚀量为27.2~31.7mg，变化较小；土下不同深度年平均溶蚀量为29.2~266.6mg。旱季与雨季土下平均溶蚀量分别为12.1~37.4mg和71.6~173.0mg，雨季最大溶蚀量发生在竹林地土下20cm处（213.6mg），而旱季最大溶蚀量则发生在稀疏乔木林地土下50cm处（57.7mg）。不同土地利用区试片土下平均溶蚀量为83.8~210.4mg/a，雨季土下溶蚀量占全年溶蚀量的57.2%~87.9%，平均为76.5%。年平均溶蚀量从大到小依次发生在竹林地、稀疏乔木林地、荒草地、人工林地与灌木林地。土下溶蚀速率为29.0~72.8t/km2·a，远高于中国西南亚热带典型峰丛洼地岩溶区，与灌木和乔木林地对比，普特热带峰丛洼地区土下溶蚀速率是我国西南亚热带的1.5~2.5倍，说明热带高温与均一化降雨过程配置以土壤有机碳快速分解产生的高CO2浓度是导致强烈岩溶作用发生的重要控制因素。土壤的演化总体上可促进岩溶作用，但过高的土壤无机碳含量和异源母质混入可能对土下溶蚀产生不利影响。
Karst processes are very sensitive to environmental factors,such as climate,hydrology and landuse.Correlation of spatial （impact of landuse） and seasonal variations of karst processes in different climate zone is helpful to revealing the short-time scale effect of karst processes.Taking a typical tropical peak depression valley catchment of Phu Toej,Sai Yok County,Kanchanaburi,Thailand as an example,dissolution rates in soil of different landuses and their controlling factors are studied and analyzed using standard tablet method.Moreover,the mean weight loss of tablets at different landuses is compared with those obtained from typical peak depression karst regions in Southwest China.Round standard tablet samples are from pure limestone of Rongxian Formation of Upper Devonian with a diameter of 40mm and a thickness of 3mm in Guilin area,Guangxi,China.Tablet placing work in soil was deployed in early November 2013 in five typical landuses,including shrubland,grass land,artificial forestland,sparse arbor forest and bamboo land.In each landuse,a representing soil profile was selected for tablet placement in air （1.5m above ground）,rock surface and soil depths of 0cm,20cm and 50cm.6 tablets were buried in each layer in which three were used for estimation of dry season dissolution rate （collected in March 2014）,three others were used for estimation of annual dissolution rate （collected in November 2014）.The results showed that the annual mean dissolution rate （tablet weight loss） in the air （1.5m above ground） is 27.2~31.7mg;annual mean tablet weight loss in soil is 29.2~266.6mg with a remarkable variation both in different sample sites and soil depth.Mean weight losses in soil in raining season and dry season are 12.1~37.4mg and 71.6~173.0mg respectively,with a maximum value of 213.6mg occurred in soil depth 20cm of bamboo land in raining season and 57.7mg occurred in soil depth 50cm of sparse arbor forest in dry season.The mean weight loss of tablets in different soil depth ranged from 83.8mg
出处
《第四纪研究》
CAS
CSCD
北大核心
2016年第6期1393-1402,共10页
Quaternary Sciences
基金
中国地质调查局地质调查项目（批准号：12120114006301和12120113006700）、广西科技厅广西重点实验室建设项目（批准号：15-140-09）、国土资源部公益性科研行业专项项目（批准号：201111022）和UNESCO/IUGS项目（批准号：IGCP598）共同资助
关键词
热带
岩溶作用
土地利用
土下溶蚀速率
泰国北碧普特流域
tropical zone, karst process, land use, dissolution rate in soil, Phu Toej catchment ofKanchanaburi, Thailand
