The analytical results of 7Be and 137Cs activities in the 28 surface soil profiles in the Yunnan Guizhou Plateau have shown that the 7Be/ 137Cs activity ratios on the topsoils reached 100-1000 in the western Yunnan, but only 10-100 for the central Guizhou region. The apparent activities and Maximum penetrative depth of 7Be in the soils of the two regions are totally close. However, 137Cs activities in the surface soils in the central Guizhou are overall a little higher than that in the western Yunnan. The phenomena that 7Be inventories in the soil cores at the most sampling sites in the central Guizhou were relatively low would just reflect the serious soil erosion in the region. 7Be inventories in the soil cores in the western Yunnan obviously differed from that in the central Guizhou, which mainly embodied that the 7Be inventories in the soil cores in the Lake Lugu watershed in Summer Autumn were apparently higher than that in Lake Hongfeng/Baihua watershed and also higher than that in Lake Erhai watershed as well. This could be related to 7Be high precipitation in summer and altitude. To explain the regional differences of 7Be/ 137Cs activity ratio on the topsoils between the western Yunnan and the central Guizhou, the accumulative characteristics of 7Be and 137Cs in the lake sediments should be further understood.
BAI Zhan-guo, WAN Guo-jiang
. A Comparative Study on Distribution of 7Be and 137Cs in the Surface Soils in the Western Yunnan and the Central Guizhou Provinces[J]. SCIENTIA GEOGRAPHICA SINICA, 2002
, 22(1)
: 43
-48
.
DOI: 10.13249/j.cnki.sgs.2002.01.43
[1] 万国江.环境质量的地球化学原理[M]北京:中国环境科学出版社,1988.1～216
[2] Santschi P H. Radionuclides as tracers for sedimentation and remobilization processes in the ocean and on lakes[A]. In: Sly P G. Sediments and water interactions[C]. New York: Springer - Verlag, 1986. 437 - 449.
[3] Ritchie J C. 137Cs use in estimating soil erosion: 30 years of research[A]. In: IAEA. Use of 137Cs in the study of soil erosion and sedimentation[C]. IAEA - TECDOC - 1028. Vienna,Austria, 1998. 5-12.
[4] Wan G J, Santschi P H, Sturm M et al. Natural (210Pb, 7Be) and fallout (137Cs, 239,240Pu, 90Sr) radionuclides as geochemical tracers of sedimentation in Greifensee, Switzerland[J]. Chemical Geology, 1987, 63:181 - 196.
[5] 白占国,万国江,王长生,等.黔中岩溶山区表土层中7Be的分布特征及其侵蚀示踪研究[J]自然科学进展,1997.7(1):66～74.
[6] 白占国,万国江,Santschi P H宇宙线散落核素7Be在山区表土中的分布特征及侵蚀示踪原理[J].土壤学报,1998,35(2):266～275
[7] Steinmann P, Billen T, Loizeau J, et al. Beryllium - 7 as a tracer to study mechanisms and rates of metal scavenging from lake surface waters[J]. Geochimica et Cosmochimica Acta,1999, 63(11 - 12): 1621 - 1633.
[8] Feng H, Cochran J K, Hirschberg D J. 234Th and 7Be as tracers for the transport and dynamics of suspended particles in a partially mixed estuary[J]. Geochimica et Cosmochimica Acta, 1999,63(17): 2487 - 2505.
[9] Blake W H, Wailing D E, He Q. Fallout beryllium - 7 as a tracer in soil erosion investigations[J]. Applied Radiation and Isotopes, 1999, 51(5): 599-605.
[10] Brown R B, Kling G F, Cutshall N H. Agricultural erosion indicated by 137Cs redistribution: Ⅱ. Estimates of erosion rates[J]. Soil Science Soc Am J, 1981, 45:1191 - 1197.
[11] 万国江,Santschi P H瑞士Greifen湖沉积物中放射性核素累计值预测研究[J]地理科学,1987,7(4):358～363.
[12] 万国江,林文祝,黄荣贵,等红枫湖沉积物137Cs垂直剖面的计年特征及侵蚀示踪[J]科学通报,1990,35(19):1487～1490
[13] 万国江.现代沉积年分辨的137Cs计年一以云南洱海和贵州红枫湖为例[J]第四纪研究,1999,(1):73～80.
[14] 张信宝,李少龙,王成华,等.黄土高原小流域泥砂来源的137Cs法研究[J]科学通报,1989,34(3):210～213
[15] WallingDE, HeQ, BlakeW. Use of 7Be and 137Cs measurements to document short-and medium-term rates of water-induced soil erosion on agricultural land[J]. Water Resources Research, 1999, 35(12): 3865 - 3874.
[16] Ritchie J C, Rasmussen P E. Application of 137Cesium to estimate erosion rates for understanding soil carbon loss on lorg-term experiments at Pendleton, Oregon[J]. Land Degradation & Development, 2000, 11: 75-81.
[17] Lu X X, Higgitt D L. Estimating erosion rates on sloping agricultural land in the Yangtze Three Gorges, China, from caesium- 137 measurements[J]. Catena, 2000, 39: 33-51.
[18] Bai Zhanguo, Wan Guojiang, Wang Changsheng, et al. 7Be: A geochemical tracer for seasonal erosion of surface soil in watershed of lake Hongfeng, Guizhou, China[J]. Pedosphere, 1996, 6(1): 23-28.
[19] 白占国,万国江,王长生,等.岩溶山区表土中7Be、137Cs、226Ra和228Ra的地球化学相分配及其侵蚀示踪意义[J].环境科学学报,1997,17(4):407～411.
[20] Turekian K K, Benninger L K, Dion E P. 7Be and 210Pb total deposition fluxes at New Haven, Connecticut and at Bermuda[J]. Journal of Geophysical Research, 1983, 88(C9): 5411-5415.
[21] KUeR (Kommission zur Uberwachung der Radioaktivitat) Bericht. 25 Jahre Radioaktivitat Uberwachung in der Schweiz[R]. Phys. Inst., Univ. of Freiburg, Freiburg, 1982.
[22] Baskaran M, Coleman C H, Santschi P H. Atmospheric depositional fluxes of 7Be and 210Pb at Galveston and College Station, Texas[J]. Journal of Geophysical Research, 1993, 98 (D11): 20555 - 20571.
[23] SchulerC, WielandE, SantschiPH, etal. A multitracerstudyof radionuclides in Lake Zurich, Switzerland. 1. Comparison of atmo spheric and sedimentary flux of 7Be, 10Be, 210pb, 210po and 137Cs[J]. J. Geophys. Res., 1991, 96(C9): 17051- 17065.
