Sediment source identification by using ^(137)_Cs and ^(210)Pb radionuclides in a small catchment of the Hilly Sichuan Basin, China
Sediment source identification by using ^(137)_Cs and ^(210)Pb radionuclides in a small catchment of the Hilly Sichuan Basin, China作者机构:InstituteofMountainHazardsandEnvironmentChineseAcademyofSciencesChengdu610041China DepartmentofGeographyandArchaeologyExeterUniversityExeterEX44RJUK ChinaWestNormalUniversityNanchong637002China
出 版 物:《Chinese Science Bulletin》 (CHINESE SCIENCE BULLETIN)
年 卷 期:2004年第49卷第18期
页 面:1953-1957页
核心收录:
学科分类:08[工学] 081502[工学-水力学及河流动力学] 0815[工学-水利工程]
基 金:National Natural Science Foundation of China,NSFC: 40271015 Chinese Academy of Sciences,CAS: 330,KZCX3-SW 422 International Atomic Energy Agency,IAEA: 12322/RO Ministerio de Ciencia y Tecnología,MICYT: 2001 CCBOOIOO,2003CB415202
主 题:泥沙来源 ^137Cs ^210Pb 放射性核 四川盆地 相对贡献法 巫江
摘 要:Double radionuclide tracers of 137Cs and 210Pb were used to investigate sediment sources in the Wujia Gully, a small catchment in the Hilly Sichuam Basin in 2002. Aver-age 137Cs and 210Pb concentrations in the source soils of the steep forest slopes, gentle cultivated terraces and bare slopes were 7.15±0.40 and 162.01±3.86 Bqkg-1, 4.01±0.31 and 70.96±2.65 Bq·kg-1, and 0 and 15.12±1.22 Bq·kg-1, re-spectively, while those concentrations in the recently depos-ited sediments in the reservoir were 3.06±0.23 and 72.66±1.61 Bq·kg-1, respectively. By using the mixing model, the relative sediment contributions from steep forest slopes, gen-tle cultivated terraces and bare slopes (including channel banks) were estimated to be 18%, 46% and 36%, respec-tively. Cultivated terraces and bare slopes (including channel banks) were the first and the second important sediment sources in catchment. Specific sediment yield in the catch-ment was 642 t·km-2·a-1 from the deposited sediment volume in the reservoir since 1956. Soil erosion rates for the forest slopes and cultivated terraces, which accounted for 2/3 and 1/3 of the drainage area in the catchment, were esti-mated to be 173 and 886 t·km-2·a-1, respectively.