基于 137Cs和 210Pbex方法的高寒草甸坡面土壤侵蚀示踪

Using137Cs and 210Pbex to Estimate Soil Redistribution Rates on a Hillslope of an Alpine Meadow

中文关键词:  137Cs  210Pbex  土壤侵蚀  高寒草甸

英文关键词:Caesium-137  Excess lead-210  Soil redistribution rates  Alpine meadow

中文摘要:

      高寒草甸是青藏高原主要的草地类型之一。为了解高寒草甸坡面土壤侵蚀特征，以兴海盆地高寒草甸坡面为研究区，分析了高寒草甸坡面上 137Cs和 210Pbex的分布特征；利用 137Cs和 210Pbex示踪方法，通过转换模型估算了高寒草甸坡面土壤侵蚀速率，并对两种方法估算的结果进行了对比。结果表明:(1)选取的高寒草甸背景土壤剖面上 137Cs质量活度最大值分布在 2～4 cm层位， 210Pbex质量活度最大值出现在最表层。(2)研究区坡面 137Cs和 210Pbex质量活度和通量在不同的坡位有明显的差异。(3)根据 210Pbex估算的土壤侵蚀速率高于基于 137Cs估算的土壤侵蚀速率，表明研究区近几十年土壤侵蚀可能呈增加趋势。(4)根据 137Cs和 210Pbex估算的土壤侵蚀速率具有极显著的正相关关系( r = 0.94，P <

英文摘要:

      In order to investigate soil erosion in alpine meadow hillslope，taking an alpine meadow hillslope of Xinghai Basin as the study area，the distribution characteristics of 137Cs and 210Pbex in soils were analyzed. Based on 137Cs and 210Pbex tracing methods，soil redistribution rates of the hillslope were assessed，the esti. mated results of the two methods were compared. The results showed that，1)The maximum mass activity of 137Cs in reference site was found in the layer of 2 ~ 4 cm，and the maximum mass activity of 210Pbex occurred in topsoil. 2)The 137Cs and 210Pbex mass activities and inventories of the hillslope were different at different slope positions，3)The soil redistribution rates estimated by 210Pbex were higher than that of 137Cs，indicating that the soil erosion in the study area may be increased in recent decades. 4)The soil redistribution rates esti. mated based on 137Cs and 210Pbex have a very significant positive correlation，showing the potential of 210Pbex combination with or replacing137Cs in tracing soil erosion in alpine meadow region.