210Pb(ex) depth distribution in soil and calibration models for assessment of soil erosion rates from 210Pb(ex) measurements

作     者：ZHANGXinbao D.E.Walling FENGMingyi WENAnbang 

作者机构：StateKeyLaboratoryofLoessandQuaternaryGeologyInstituteofEarthEnvironmentCASXi'an710075China DepartmentofGeographyandArchaeologyExeterUniversityExeterUKEX44RJ ChengduInstituteofMountainHazardsandEnvironmentChineseAcademyofSciences(CAS)Chengdu610041China 

出 版 物：《Chinese Science Bulletin》 (中国科学通报)

年 卷 期：2003年第48卷第8期

页      面：813-818页

核心收录：

学科分类：082802[工学-农业水土工程] 090707[农学-水土保持与荒漠化防治] 0907[农学-林学] 08[工学] 0828[工学-农业工程] 09[农学] 0815[工学-水利工程] 

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.40271015 and 900102017) the Stiate Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,the Chinese Acatemy of Sciences(CAS)(Grant No.SKLLQG0206) the Knowledge Innovation Project of Water Erosion Prediction Modeling of CAS(Grant No.KZCX3-SW-422) IAEA(12322/RO) 

主　　题：^210Pbex 铅 土壤侵蚀 铯 铀 

摘      要：Three soil cores collected from China and UK show the 210Pbex and 137Cs depth distribution on uncultivated and cultivated land. Depth distributions of the two nuclides are very similar. Those nuclide concentrations are higher in the top horizon and decrease exponentially with depth on uncultivated land while the concentrations are almost uni-form throughout the plough layer as a result of mixing asso-ciated with cultivation on cultivated land. 210Pbex reference inventory in the Loess Plateau is 573 mBq·cm-2, a little higher than 520.0 mBq·cm-2 in UK. Distribution of artificial fallout 137Cs, produced during the nuclear testing period of the late 1950s and 1960s, is in an unsteady state. In contrast, distribution of natural fallout 210Pbex is in a steady state un-der constant conditions of land environment and erosion processes for a long term, e.g. 100 years. Therefore, mass balances of 137Cs and 210Pbex in soil are different. According to its processes of continues deposition from the atmosphere, nature decay and losses with soil losses, 210Pbex steady state mass balance models for cultivated land as well as for uncul-tivated land are developed to estimate soil erosion rates in this paper. Besides, the proportion of freshly deposited 210Pbex fallout removed by erosion on cultivated land can also be calculated from 210Pbex depth distribution at a reference site of uneroded permanent grass land.