摘要
滇西和黔中 2 8个表土剖面分层土样7Be、1 3 7Cs比活度对比分析可见 :滇西地区表土层顶部7Be 1 3 7Cs为 10 0～ 10 0 0 ,而黔中地区仅 10～ 10 0 ;两地区表土层中7Be的表观比活度和最大渗透深度总体相近 ;1 3 7Cs在黔中表土层中的比活度总体较滇西地区略高。而黔中表土中7Be累计值的偏低现象 ,映射了该地区强烈的水土流失。为解释滇西和黔中地区之间表土层顶部7Be 1 3 7Cs的地区差异 ,需进一步讨论两核素的湖泊沉积物蓄积特征。
The analytical results of 7Be and 137 Cs activities in the 28 surface soil profiles in the Yunnan Guizhou Plateau have shown that the 7Be/ 137 Cs 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, 137 Cs 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/ 137 Cs activity ratio on the topsoils between the western Yunnan and the central Guizhou, the accumulative characteristics of 7Be and 137 Cs in the lake sediments should be further understood.
出处
《地理科学》
CSCD
北大核心
2002年第1期43-48,共6页
Scientia Geographica Sinica
基金
国家自然科学基金 ( 4 99710 5 3
497732 0 7
49894170
493330 40 )
瑞典国际科学基金 (A 2 70 4-1
IFSofSweden)
关键词
散落
蓄积
表土
贵州
广西
放射性核素
铯
铍
Cs and 7Be
deposition and accumulation
surface soil
west Yunnan and central Guizhou.
