Development of a prediction model for ambient dose equivalent rate distribution based on ecological half-life profiles using LASSO regression and KURAMA data.

IF 0.7 4区 环境科学与生态学 Q4 ENVIRONMENTAL SCIENCES
Yoshiaki Shikaze, Kimiaki Saito, Naoki Tanimura, Kazuya Yoshimura, Liu Xudong, Masahiko Machida
{"title":"Development of a prediction model for ambient dose equivalent rate distribution based on ecological half-life profiles using LASSO regression and KURAMA data.","authors":"Yoshiaki Shikaze, Kimiaki Saito, Naoki Tanimura, Kazuya Yoshimura, Liu Xudong, Masahiko Machida","doi":"10.1093/rpd/ncaf086","DOIUrl":null,"url":null,"abstract":"<p><p>The two-component model, comprising a fast-decay and a slow-decay component, has been widely used to approximate the decreasing trends of air dose rates in contaminated areas surrounding major nuclear accident sites. However, its adequacy is yet to be thoroughly validated. This study analyzed extensive car-borne survey data collected from 2011 to 2016 after the Fukushima Daiichi Nuclear Power Plant accident using the least absolute shrinkage and selection operator regression with a high-degree-of-freedom model. This analysis aimed to evaluate the adequacy of the two-component model and investigate the profiles of ecological half-lives. The results demonstrate that the two-component model can approximate the decreasing trend of air dose rates in the Fukushima area well in most cases. However, in ~20% of the cases, the one-component model provided a better fit. The fast-decay component in the two-component model exhibited a sharp ecological half-life peak below 1 y, with a frequency distribution peaking at 0.3-0.4 y. In contrast, the slow-decay component displayed a broader half-life peak in approximately half of the cases, with a frequency distribution spanning several years to over 50 y. The reduction speed of air dose rates was fastest in urban areas, followed by paddy fields, croplands, deciduous forests, and evergreen forests. The reduction speed decreased as the initial air dose rate increased, a trend explained by the weight assigned to the fast-decay component rather than the value of its ecological half-life. Future predictions of air dose rate distributions were made using a prediction model formula that incorporated the average ecological half-life profiles calculated for each land-use and initial air dose rate category. Prediction accuracy was verified through comparison with integrated map data, which merge air dose rate datasets obtained using different monitoring methods and represent the most currently reliable source. The predicted values tended to decay faster overall than the integrated map data, with an average deviation within 10% over the six-year period. This discrepancy arises because the car-borne survey data were collected on paved roads, where air dose rates decrease rapidly due to the quick washout of radiocesium. The differences between the prediction model values and integrated map values were larger for forests than for farmlands (paddy fields and croplands) and urban areas. This suggests that the reduction in air dose rates is slower in pure forests, where the car-borne surveys were rarely conducted.</p>","PeriodicalId":20795,"journal":{"name":"Radiation protection dosimetry","volume":" ","pages":"1025-1042"},"PeriodicalIF":0.7000,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiation protection dosimetry","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1093/rpd/ncaf086","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0

Abstract

The two-component model, comprising a fast-decay and a slow-decay component, has been widely used to approximate the decreasing trends of air dose rates in contaminated areas surrounding major nuclear accident sites. However, its adequacy is yet to be thoroughly validated. This study analyzed extensive car-borne survey data collected from 2011 to 2016 after the Fukushima Daiichi Nuclear Power Plant accident using the least absolute shrinkage and selection operator regression with a high-degree-of-freedom model. This analysis aimed to evaluate the adequacy of the two-component model and investigate the profiles of ecological half-lives. The results demonstrate that the two-component model can approximate the decreasing trend of air dose rates in the Fukushima area well in most cases. However, in ~20% of the cases, the one-component model provided a better fit. The fast-decay component in the two-component model exhibited a sharp ecological half-life peak below 1 y, with a frequency distribution peaking at 0.3-0.4 y. In contrast, the slow-decay component displayed a broader half-life peak in approximately half of the cases, with a frequency distribution spanning several years to over 50 y. The reduction speed of air dose rates was fastest in urban areas, followed by paddy fields, croplands, deciduous forests, and evergreen forests. The reduction speed decreased as the initial air dose rate increased, a trend explained by the weight assigned to the fast-decay component rather than the value of its ecological half-life. Future predictions of air dose rate distributions were made using a prediction model formula that incorporated the average ecological half-life profiles calculated for each land-use and initial air dose rate category. Prediction accuracy was verified through comparison with integrated map data, which merge air dose rate datasets obtained using different monitoring methods and represent the most currently reliable source. The predicted values tended to decay faster overall than the integrated map data, with an average deviation within 10% over the six-year period. This discrepancy arises because the car-borne survey data were collected on paved roads, where air dose rates decrease rapidly due to the quick washout of radiocesium. The differences between the prediction model values and integrated map values were larger for forests than for farmlands (paddy fields and croplands) and urban areas. This suggests that the reduction in air dose rates is slower in pure forests, where the car-borne surveys were rarely conducted.

利用LASSO回归和KURAMA数据建立基于生态半衰期剖面的环境剂量当量率分布预测模型。
由快衰减和慢衰减组成的双分量模型已被广泛用于估计重大核事故现场周围污染地区空气剂量率的下降趋势。然而,它的充分性还有待彻底验证。本研究采用最小绝对收缩和选择算子回归的高自由度模型,分析了福岛第一核电站事故发生后2011年至2016年收集的大量车载调查数据。本分析旨在评价双组分模型的充分性,并探讨生态半衰期的概况。结果表明,双分量模型在大多数情况下能较好地近似福岛地区空气剂量率的下降趋势。然而,在约20%的情况下,单组分模型提供了更好的拟合。双分量模型中,快速衰减分量在1 y以下有一个明显的生态半衰期峰,频率分布在0.3 ~ 0.4 y,而缓慢衰减分量在大约一半的情况下有一个更宽的半衰期峰,频率分布跨越数年至50 y以上。空气剂量率的降低速度在城市地区最快,其次是稻田、农田、落叶林和常绿森林。随着初始空气剂量率的增加,还原速度下降,这一趋势可以用快速衰变组分的权重而不是其生态半衰期的值来解释。未来空气剂量率分布的预测使用了一个预测模型公式,该公式结合了每种土地利用和初始空气剂量率类别计算的平均生态半衰期曲线。通过与综合地图数据的比较,验证了预测的准确性。综合地图数据融合了不同监测方法获得的空气剂量率数据集,代表了目前最可靠的来源。总体而言,预测值比综合地图数据衰减得更快,6年期间的平均偏差在10%以内。之所以出现这种差异,是因为车载调查数据是在铺砌的道路上收集的,由于放射性元素的快速冲刷,空气剂量率迅速下降。森林预测模型值与综合地图值的差异大于农田(水田和农田)和城市地区。这表明,在纯森林中,空气剂量率的降低速度较慢,在纯森林中,很少进行汽车携带的调查。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Radiation protection dosimetry
Radiation protection dosimetry 环境科学-公共卫生、环境卫生与职业卫生
CiteScore
1.40
自引率
10.00%
发文量
223
审稿时长
6-12 weeks
期刊介绍: Radiation Protection Dosimetry covers all aspects of personal and environmental dosimetry and monitoring, for both ionising and non-ionising radiations. This includes biological aspects, physical concepts, biophysical dosimetry, external and internal personal dosimetry and monitoring, environmental and workplace monitoring, accident dosimetry, and dosimetry related to the protection of patients. Particular emphasis is placed on papers covering the fundamentals of dosimetry; units, radiation quantities and conversion factors. Papers covering archaeological dating are included only if the fundamental measurement method or technique, such as thermoluminescence, has direct application to personal dosimetry measurements. Papers covering the dosimetric aspects of radon or other naturally occurring radioactive materials and low level radiation are included. Animal experiments and ecological sample measurements are not included unless there is a significant relevant content reason.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:604180095
Book学术官方微信