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研究137Cs在土壤剖面上的分布是应用137Cs方法定量评价土壤风力侵蚀的基础.以内蒙古太仆寺旗为研究区,采集了4个样点、共62个土壤样本;使用伽马能谱仪测定了各土壤样本的137Cs活度,计算得到各样点的137Cs总量.研究发现不同土地利用类型/土地覆盖等级的137Cs剖面分布特征差异明显.在低覆盖草地和中覆盖草地土壤剖面中,137Cs活度分布形态为负指数分布;在高覆盖草地土壤剖面中,137Cs活度分布形态在剖面上部为单峰状,单峰后继续为负指数分布;在耕地剖面中,137Cs集中在犁底层以上,且均匀分布.对耕地和草地样点分别使用质量平衡模型和剖面分布模型,可以估算得到农耕地、低覆盖草地、中等覆盖草地等3处样点的侵蚀速率分别为7990,4270和1808Mg/km2·a,分别属于强度侵蚀、中度侵蚀和轻度侵蚀,风力侵蚀强度与地面植被覆盖度呈负相关关系.
Studying the distribution of 137Cs in the soil profile is the basis for the quantitative assessment of wind erosion using 137Cs method.With Taipusiqi in Inner Mongolia as the study area, 4 samples were collected and 62 soil samples were collected. The soil samples were measured with gamma spectrometer The 137Cs activity of samples was used to calculate the total amount of 137Cs in different sampling sites.It was found that there was significant difference in 137Cs profiles between different land use types and land cover classes.Changes of 137Cs activity In the topsoil profile of high coverage grassland, the distribution of 137Cs activity was unimodal in the upper part of the profile and negative exponential distribution in the profile of 137Cs. In the profile of the cultivated land, 137Cs were concentrated above the bottom of the plow, Distribution. For the arable land and grassland sample, respectively, using the mass balance model and the profile distribution model, we can estimate the erosion rates of the three sampling sites, ie, 7990, 4270 and 1808 Mg / km2 · a , Belonging to the intensity erosion, the moderate erosion and the mild erosion respectively. The wind erosion intensity and the ground vegetation coverage have a negative correlation.