Soil erosion rates on forested mountain hillslopes estimated using 137Cs and 210Pbex
Soil erosion rates on forested mountain hillslopes estimated using 137Cs and 210Pbex
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DOI：
10.1016/j.geoderma.2010.06.012
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发表时间：
2010-10
期刊：
影响因子：
6.1
通讯作者：
Y. Wakiyama;Y. Onda;S. Mizugaki;Hiroki Asai;S. Hiramatsu
中科院分区：
文献类型：
--
作者：
Y. Wakiyama;Y. Onda;S. Mizugaki;Hiroki Asai;S. Hiramatsu
尽管过量的铅-210（210 Pbex）被描述为铯-137（137 Cs）的替代或补充核素，用于土壤侵蚀评估，但210 Pbex在森林环境中的潜在用途尚未得到充分研究。在这项研究中，调查的潜在用途210 Pbex的土壤侵蚀的评估在不同的森林山坡，我们比较了土壤侵蚀率从210 Pbex从森林中获得的137 Cs。该研究在四种类型的森林中进行：一个日本柏树站与裸露的森林地面，一个日本柏树站与蕨类植物林下，一个日本雪松站与足够的垃圾覆盖，和日本东南部津浦川流域的天然阔叶林。利用γ-射线法测量了平脊顶部和每个林分沿着样带的7个潜在参考点的137 Cs和210 Pbex含量。X射线光谱法计算土壤侵蚀速率。为了描述有机质在各林分中的行为，在日本柏木林（裸林）、日本雪松林和阔叶林的侵蚀样地（1.7-2.0m长，0.5m宽）中观察了大约2a的侵蚀沉积物和有机质的量。由Cs和Pb估算的平均侵蚀速率均以柏木林（裸地）最高，其次为柏木林（蕨类）、阔叶林和日本杉林，这种大小关系与侵蚀样地侵蚀泥沙观测结果一致。在日本柏树林（裸），一个显着的相关性被发现在日本柏树林（裸）之间的Cs-和铅为基础的土壤侵蚀速率，而没有显着性被发现在其他三个看台。这些结果为210 Pbex用于裸露林地土壤侵蚀评价的可行性提供了证据。在其他三个林分中，与有机质相关的210 Pbex的优先损失可以解释两种侵蚀速率之间的相关性较差。
Although the excess of lead-210 (210Pbex) has been described as an alternative or complementary nuclide to cesium-137 (137Cs) for soil erosion assessment, the potential use of210Pbexin forested environments has not been examined sufficiently. In this study, to investigate the potential use of210Pbexfor the assessment of soil erosion on various forested hillslopes, we compared soil erosion rates derived from210Pbexto those from137Cs obtained in forest stands. The study was conducted in four types of forest: a Japanese cypress stand with a bare forest floor, a Japanese cypress stand with a fern understory, a Japanese cedar stand with sufficient litter cover, and a natural broadleaf forested stand in the Tsuzura River basin of southeastern Japan.137Cs and210Pbexinventories for seven potential reference sites on flat ridge tops and along transects in each stand were measured using gamma-ray spectrometry to calculate soil erosion rates. To describe the behavior of organic matter in each stand, the amounts of eroded sediment and organic matter were observed for approximately 2years in erosion plots (1.7–2.0m long, 0.5m wide) in the Japanese cypress stand (bare), Japanese cedar stand, and broadleaf forest stand. From the preliminary assessment of potential reference sites, spatial variability in210Pbexwas comparable to that of137Cs. Mean erosion rates estimated from both Cs and Pb were highest in the Japanese cypress stand (bare), followed by the Japanese cypress stand (fern), the broadleaf forest stand, and the Japanese cedar stand. This magnitude relationship was consistent with that of observation results of eroded sediment in erosion plots. In the Japanese cypress stand (bare), a significant correlation was found between Cs- and Pb-based soil erosion rates in the Japanese cypress stand (bare) while no significance was found in the other three stands. These results provide evidence of the feasibility of210Pbexfor soil erosion assessment in forest stands with bare forest floors. In the other three stands, the preferential loss of210Pbexassociated with organic matter may explain the poor correlation between the two erosion rates.