Abstract

Redistribution of sediments and Chernobyl-derived ¹³⁷Сs transported with them were estimated using a set of field methods and erosion model calculations for the Shchekino reservoir (Tula region) catchment, and changes in the contents of ¹³⁷Сs in soils of various types that occurred over 1986–2018 were determined. The rate of snowmelt soil erosion on arable land during this period has decreased by about a half in comparison with that in 1960–1985 due to a reduction in soil freezing depth in winter. The rainfall erosion rate increased by about a third between 1986–2003 due to an increase in the rainfall erosivity index; after that, it tended to decrease synchronously with a decrease in the rainfall erosivity. The total average annual soil loss related to water erosion varies in the range of 1.3–1.6 t ha^–1 depending on the soil type. The erosional loss of ¹³⁷Сs from arable land averaged 1.5–2% of its total inventory, which decreased by more than a half in comparison with the initial inventory in May 1986 due to natural decay. On 0.4% of the arable land with maximum rates of erosion, the decrease in the ¹³⁷Сs inventory reached 12–40% from the initial inventory. More than 90% of ¹³⁷Сs washed away with sediments from arable lands were redeposited along the transportation pathway from arable fields to permanent streams. The total soil ¹³⁷Сs inventory exceeded its initial inventory at the time of fallout from the atmosphere in May 1986 in the bottoms of hollows in areas from the lower edge of the arable land to the upper reaches of dry first-order valleys due to high sedimentation rates. The ¹³⁷Сs inventory exceeded the lower threshold of permissible radioactive contamination of soils (37 kBq m^–2) also in some other sediment sinks (bottoms of dry valleys, foot of plowed slopes, and a low floodplain of rivers) due to the accumulation of contaminated sediments.

中文翻译：

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什奇基诺水库（图拉地区）盆地侵蚀是土壤放射性污染转化的一个因素

摘要

沉积物和切尔诺贝利衍生的再分配^137个Сs与他们运送用的一组字段的方法和侵蚀模型计算得出的该Shchekino贮存器（图拉区域）集水估计，和改变的内容¹³⁷确定了1986-2018年间各种类型土壤中的Сs。与1960-1985年相比，由于冬季土壤冰冻深度的减少，这段时期耕地上融雪的土壤侵蚀速率下降了约一半。由于降雨侵蚀力指数的增加，1986-2003年间降雨侵蚀率增加了约三分之一。此后，其趋向于与降雨侵蚀力的降低同步降低。与水蚀有关的年平均总土壤流失量在1.3–1.6 t ha ^–1范围内变化，具体取决于土壤类型。侵蚀损失¹³⁷耕地中的有机碳平均占其总库存的1.5–2％，由于自然衰退，与1986年5月的初始库存相比，减少了一半以上。在具有侵蚀的最大速率耕地的0.4％，在减少^137个Сs库存从最初的库存达到了12-40％。超过90％的¹³⁷ Сs冲走与耕地沉积物沿着畴永久流的运输途径再沉积。土壤总¹³⁷ Сs库存超过其在从大气沉降的时间初始库存在1986年5月在凹陷的底部中的区域从耕地到干燥一阶谷的上游的下边缘，由于高沉降费率。在¹³⁷由于受污染的沉积物的积累，其存量也超过了其他一些沉积物库（干燥山谷的底部，耕坡的山脚和河流泛滥的平原）中土壤允许的放射性污染的最低阈值（37 kBq m ^–2）。 。