西南喀斯特流域泥沙来源、输移、平衡的思考——基于坡地土壤与洼地、塘库沉积物^(137)Cs含量的对比  

Contrast of ^(137)Cs Content in Slope Soil with Depressions,and Pond Sediments——Sediments Sources,Transportion and Balance of Karst Basin in SW China

作　　者：张信宝[1,2] 白晓永[2,3] 李豪[4] 冯腾[5] 彭涛[2,3] 严东春 何永彬[6] 鲍玉海[1] 汪阳春[1] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,成都610041 [2]中国科学院普定喀斯特生态系统观测研究站,贵州普定562100 [3]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002 [4]四川农业大学,成都611130 [5]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [6]云南大学云南省地理研究所,昆明650223

出　　处：《地球与环境》2017年第3期247-258,共12页Earth and Environment

基　　金：国家重点研发计划项目(2016YFC0502300;2016YFC0502102);国家重点基础研究发展计划"973"项目(2013CB956700);国家科技支撑计划(2014BAB03B02);国家自然科学基金(U1612441;41571130074;41571130042);贵州社会发展科技攻关计划项目(2012-6015;2013-3190;201742920512120000);中国科学院院地合作项目(2014-3)

摘　　要：汇总了西南喀斯特地区坡地土壤和洼地、塘库沉积泥沙的^(137)Cs比活度资料,并进行了对比,分析流域泥沙来源。坡地地面流失轻微的,汇水面积小于0.5 km^2的微小流域,流域产沙主要源于地下流失(裂隙土)和沟岸侵蚀(沟壁土);坡地地面流失强烈的,主要源于坡地地面流失(坡地表层土壤)。地下流失和沟岸侵蚀是小流域和较大流域的主要产沙方式,且有随着流域面积增大,产沙贡献率越高的趋势。由于裂隙土和沟壁土都基本不含^(137)Cs,^(137)Cs单一示踪法不能区分这两种源地土体的产沙贡献率。建议采用多元示踪法,研究流域的泥沙来源。区分裂隙土和沟壁土的产沙贡献率,可考虑尝试磁性法和孢粉法。通过沉积物^(137)Cs断代等方法确定洼地、河流滩地和塘库泥沙淤积量,结合径流小区和水文站输沙量资料,分析不同类型洼地、河流滩地和塘库的泥沙截留率,分析河流泥沙输移比。在查明泥沙来源,泥沙输移比和输沙量(或产沙量)的基础上,确定流域泥沙平衡,结合径流研究成果,建立喀斯特流域产沙模型。The 137Cs contents in slope soil, depressions and pond sediments were analysis and compared to learn the sources of sediment in SW China in this paper. Results show（1） in small karst basin, where catchment area is lower than 0.5 km2 and its erosion of ground on karst slope is very slight, sediment yield is mainly from underground loss （fractured earth）and ditch bank erosion（ trench walls soil） ; （2）in some karst basin, where ground erosion on slope is strong, sediment yield is mainly from slope ground loss（ surface soil） ; （3） underground loss and ditch bank erosion are the main ways for sediment yield in small watershed and larger basins, respectively. And there is positive correlation between sediment yield contribution and drainage area; （4）there is no 137Cs contents in fractured earth and trench walls soil can be tested, therefore, sediment contribution between these two sources can not be to distinguished by 137Cs trac- er method; （5） the multi-tracer technique was recommended to study sediment sources of karst basin; （6） if the contribution of sedi- ment was distinguished between fractured earth and trench walls soil, the magnetic method and pollen methods would be recommended ; and （7）to determine sediment volume in depressions, river beaches and pond sediments by 137Cs tracer method, and to analysis sedi- ment retention of different depressions, beaches and ponds and sediment transport ratio of rivers, eomhined with tke data of runoff plots and hydrological station. On the basis of the identification of sediment sources, sediment delivery ratio and sediment load（ or sediment yield） , to determine the balance of basin sediment and establishment sediment yield mode of karst drainage basin combining research results of runoff plots.

关 键 词：喀斯特流域 泥沙来源 输移 137Cs含量 

分 类 号：X141[环境科学与工程—环境科学]