Abstract:With the increasing development of industry and agriculture in China, heavy metal pollution in soil represented by nickel (Ni), iron (Fe), copper (Cu), chromium (Cr), lead (Pb), etc., has a serious impact on human life. Hyperspectral technology has advantages such as being real-time, non-destructive, and fast, which provides scientific means to obtain information on soil heavy metal content efficiently and accurately. At the same time, the spectral transformation method significantly impacts the inversion accuracy of soil heavy metal content. To clarify the relationship between the spectral transformation method and the inversion accuracy, 60 soil samples were collected in the study area to determine the Ni, Fe, Cr, Cu, and Pb heavy metals content and the corresponding spectral reflectance between 350~2 500 nm. Based on the correlation coefficient (CC) analysis, the feature bands for remote sensing detection of soil heavy metals were selected by the modified discrete binary particle swarm optimization (MDBPSO) method. Finally, the inverse models of Ni, Fe, Cr, Cu and Pb contents were constructed by the random forest (RF) algorithm with the feature bands as independent variables. In this study, based on Gaussian smoothing of the original reflectance, the effects of four differential spectral transformation methods, including first-order differential (R′), first-order differential of logarithmic inverse (1/lgR)′, first-order differential of inverse (1/R)′, and first-order differential of exponential (eR)′, on the accuracy of soil heavy metal inversion were compared and analyzed. The results show that based on the CC analysis method, the MDBPSO algorithm can effectively reduce the redundancy of spectral data and improve the efficiency of the model operation. The number of feature bands sensitive to Ni, Fe, Cr, Cu and Pb in R′, (1/lgR)′, (1/R)′, (eR)′, has been reduced by at least 154, 363, 135, 744 and 889, respectively. (1/lgR)′, R′, R′, (1/R)′, and R′ spectral transformation methods were applied to the combined operation of Ni, Fe, Cr, Cu, and Pb feature bands, respectively. The accuracy of the estimated models was better than other differential transformation methods, where the coefficients of determination of the model test set were 0.913, 0.906, 0.872, 0.912, and 0.876. The root mean square errors were 0.743, 0.095, 2.588, 1.541, and 1.453, respectively. This study provides a scientific reference for selecting of differential spectral transformation methods when using remote sensing data to retrieve soil heavy metal content. It provides new ideas for further realizing large-area high-precision remote sensing monitoring of soil heavy metal content.
Key words:Remote sensing; Hyperspectral; Soil; Spectral transformation method; Heavy metals; Modified discrete binary particle swarm optimization; Random forests
白宗璠,韩 玲,姜旭海,武春林. 微分光谱变换方法对土壤重金属含量反演精度的影响研究[J]. 光谱学与光谱分析, 2024, 44(05): 1449-1456.
BAI Zong-fan, HAN Ling, JIANG Xu-hai, WU Chun-lin. Effect of Differential Spectral Transformation on Soil Heavy
Metal Content Inversion Accuracy. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2024, 44(05): 1449-1456.
[1] QIAN Jia-wei, LIU Xiao-qing, ZHANG Jing-jing, et al(钱家炜, 刘晓青, 张静静, 等). Acta Agriculturae Zhejiangensis(浙江农业学报), 2020, 32(8): 1437.
[2] LIU Yan-ping, LUO Qing, CHENG He-fa(刘彦平, 罗 晴, 程和发). Journal of Agro-Environment Science(农业环境科学学报), 2020, 39(12): 2699.
[3] Liu K, Zhao D, Fang J Y, et al. Journal of the Indian Society of Remote Sensing, 2017, 45(5): 805.
[4] MA Chi(马 驰). Transactions of the Chinese Society of Agricultural Engineering(农业工程学报), 2020, 36(20): 164.
[5] Han L, Chen R, Zhu H, et al. Sustainability, 2020, 12(4), 1476.
[6] Liu Z, Lu Y, Peng Y, et al. Remote Sensing, 2019, 11(12), 1464.
[7] GUO Yun-kai, ZHANG Qiong, QIAN Jia, et al(郭云开, 章 琼, 钱 佳, 等). Engineering of Surveying and Mapping(测绘工程), 2020, 29(6): 56.
[8] Tan K, Ma W, Chen L, et al. Journal of Hazardous Materials, 2021, 401: 123288.
[9] Tian S Q, Wang S J, Bai X Y, et al. Chinese Journal of Geochemistry, 2020, 39(3): 423.
[10] WANG Yu-na, LI Fen-ling, WANG Wei-dong, et al(王玉娜, 李粉玲, 王伟东, 等). Journal of Triticeae Crops(麦类作物学报), 2020, 40(11): 1389.
[11] ZHOU Ding-hao, XUE Li-hong, LI Ying, et al(周鼎浩, 薛利红, 李 颖, 等). Soils(土壤), 2014, 46(1): 47.
[12] ZHANG Dong-hui, ZHAO Ying-jun, QIN Kai, et al(张东辉, 赵英俊, 秦 凯, 等). Transactions of the Chinese Society of Agricultural Engineering(农业工程学报), 2018, 34(20): 141.
[13] XU Kai-jian, TIAN Qing-jiu, XU Nian-xu, et al(徐凯健, 田庆久, 徐念旭, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2019, 39(12): 3794.
[14] Yang C, Tan Y L, Bruzzone L, et al. Remote Sensing, 2017, 9: 782.
[15] Zhang X, Yang G, Yang Y, et al. Proc SPIE, 2016, 10156: 1015605.
[16] ZHANG Jue, TIAN Hai-qing, ZHAO Zhi-yu, et al(张 珏, 田海清, 赵志宇, 等). Transactions of the Chinese Society of Agricultural Engineering(农业工程学报), 2019, 35(1): 285.
[17] DING Hai-ning, CHEN Yu, CHEN Yun-zhi(丁海宁, 陈 玉, 陈芸芝). Remote Sensing Technology and Application(遥感技术与应用), 2019, 34(2): 275.
[18] TONG Qing-xi, ZHANG Bing, ZHENG Lan-fen(童庆禧, 张 兵, 郑兰芬). Hyperspectral Remote Sensing-Principles, Techniques and Applications(高光谱遥感——原理、技术与应用), Beijing: Higher Education Press(北京:高等教育出版社), 2015.
[19] PU Rui-liang, GONG Peng(浦瑞良, 宫 鹏). Hyperspectral Remote Sensing and Its Applications(高光谱遥感及应用), Beijing: Higher Education Press(北京:高等教育出版社), 2003.
[20] Kennedy J, Eberhart R. A Discrete Binary Version of the Particle Swarm Algorithm. International Conference on Systems, Man, and Cybernetics. Computational Cybernetics and Simulation, 1997, 5: 4104.
[21] CAO Yin, YE Yun-tao, ZHAO Hong-li, et al(曹 引, 冶运涛, 赵红莉, 等). Transactions of the Chinese Society for Agricultural Machinery(农业机械学报), 2018, 49(1): 173.
[22] BAI Zong-fan, JING Xia, ZHANG Teng, et al(白宗璠, 竞 霞, 张 腾, 等). Acta Agronomica Sinica(作物学报), 2020, 46(8): 1248.
[23] Wang L, Zhou X D, Zhu X K, et al. The Crop Journal, 2016, 4(3): 212.
[24] YAO Xiong, YU Kun-yong, YANG Yu-jie, et al(姚 雄, 余坤勇, 杨玉洁, 等). Transactions of the Chinese Society for Agricultural Machinery(农业机械学报), 2017, 48(5): 159.
[25] Breiman L. Machine Learning, 2001, 45(1): 5.
[26] Rodriguez-Galiano V, Mendes M P, Garcia-Soldado M J, et al. Science of the Total Environment, 2014, 476-477: 189.
[27] WANG Li-ai, MA Chang, ZHOU Xu-dong, et al(王丽爱, 马 昌, 周旭东, 等). Transactions of the Chinese Society for Agricultural Machinery(农业机械学报), 2015, 46(1): 259.
[28] XIE Xian-li, SUN Bo, HAO Hong-tao(解宪丽, 孙 波, 郝红涛). Acta Pedologica Sinica(土壤学报), 2007, 44(6): 982.
[29] ZHANG Hui-juan, ZHANG Da-min, YAN Wei, et al(张绘娟, 张达敏, 闫 威, 等). Computer Science(计算机科学), 2019, 46(10): 109.
[30] Cao Y, Ye Y T, Zhao H L, et al. Ecological Informatics, 2018, 44: 21.