标题：Estimating lead and zinc concentrations in peri-urban agricultural soils through reflectance spectroscopy: Effects of fractional-order derivative and random forest
作者： Hong, YS (Hong, Yongsheng); Shen, RL (Shen, Ruili); Cheng, H (Cheng, Hang); Chen, YY (Chen, Yiyun); Zhang, Y (Zhang, Yong); Liu, YL (Liu, Yaolin); Zhou, M (Zhou, Min); Yu, L (Yu, Lei); Liu, Y (Liu, Yi); Liu, YF (Liu, Yanfang)
来源出版物：SCIENCE OF THE TOTAL ENVIRONMENT 卷：651 part:2页码：1969-1982 DOI：10.1016/j.scitotenv.2018.09.391 出版年： FEB 15 2019
摘要：Heavy metal contamination of peri-urban agricultural soil is detrimental to soil environmental quality and human health. A rapid assessment of soil pollution status is fundamental for soil remediation. Heavy metals can be monitored by visible and near-infrared spectroscopy coupled with chemometric models. First and second derivatives are two commonly used spectral preprocessing methods for resolving overlapping peaks. However, these methods may lose the detailed spectral information of heavy metals. Here, we proposed a fractional-order derivative (FOD) algorithm for preprocessing reflectance spectra. A total of 170 soil samples were collected from a typical peri-urban agricultural area in Wuhan City, Hubei Province. The reflectance spectra and lead (Pb) and zinc (Zn) concentrations of the samples were obtained in the laboratory. Two calibration methods, namely, partial least square regression and random forest (RF), were used to establish the relation between the spectral data and the two heavy metals. In addition, we aimed to explore the use of spectral estimation mechanism to predict the Pb and Zn concentrations. Three model evaluation parameters, namely, coefficient of determination (R-2), root mean squared error, and ratio of performance to inter-quartile range (RPIQ), were used. Overall, the spectral reflectance decreased with the increase in Pb and Zn contents. The FOD algorithm gradually removed spectral baseline drifts and overlapping peaks. However, the spectral strength slowly decreased with the increase in fractional order. High fractional-order spectra underwent more spectral noises than low fractional-order spectra. The optimal prediction accuracies were achieved by the 0.25- and 0.5-order reflectance RF models for Pb (validation R-2 = 0.82, RPIQ = 2.49) and Zn (validation R-2 = 0.83, RPIQ = 2.93), respectively. A spectral detection of Pb and Zn mainly relied on their covariation with soil organic matter, followed by Fe. In summary, our results provided theoretical bases for the rapid investigation of Pb and Zn pollution areas in peri-urban agricultural soils.
作者关键词： Proximal soil sensing; Soil heavy metal; Spectral derivative; Predictive model; Estimation mechanism
通讯作者地址：Chen, YY; Liu, YF (reprint author), Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.
[Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yaolin; Zhou, Min; Liu, Yi; Liu, Yanfang] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.
[Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yi] Chinese Acad Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China.
[Shen, Ruili] Hubei Acad Environm Sci, Wuhan 430072, Hubei, Peoples R China.
[Zhang, Yong] Anhui Univ Finance & Econ, Sch Publ Finance & Adm, Bengbu 233030, Peoples R China.
[Yu, Lei] Cent China Normal Univ, Sch Urban & Environm Sci, Wuhan 430079, Hubei, Peoples R China.
[Yu, Lei] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Hubei, Peoples R China.
版权所有 © 武汉大学资源与环境科学学院