Spectral Angles of Plant Leaves as Indicators of Uranium Pollution in Soil
WANG Wei-hong1, 2*, LUO Xue-gang1, 3, WU Feng-qiang1, 2, LIN Ling1, 2, LI Jun-jie1, 2
1. Environment and Resource College, Southwest University of Science and Technology, Mianyang 621010,China
2. Mianyang S&T City Division,the National Remote Sensing Center of China, Mianyang 621010,China
3. Engineering Research Center of Biomass Materials of Ministry of Education,Mianyang 621010,China
Abstract:In this paper, five plants (ramie, Indian mustard, Rumex, Brassica napus and maize) were pot cultured with 0 (control group), 25, 75, 125, 175, 275, 375 and 485 μg·g-1 uranium in the soil. The qualitative and quantitative indicating effects of leaf spectral angle on soil uranium pollution in different growth stages were studied, and the relationship between quantitative indicating effect and leaf uranium content was analyzed It provides an effective way to quickly and safely carry out the background investigation and dynamic monitoring of soil uranium content through field measurement of plant leaf spectrum. The results and main conclusions are as follows: (1) Based on the leaf reflectance spectra of experimental plants in different growth stages, the spectral angles of soil polluted by uranium in five bands (350~716 nm for leaf pigment, 717~975 nm for red edge and near infrared platform, 976~1 265, 1 266~1 770 and 1 771~2 500 nm for water) were calculated. In most cases, the spectral angles of the five experimental plants were greater than the thresholds of the control group. The spectral angles of leaves havecomprehensive responses of 350~2 500 nm to theuranium in soil, which can qualitatively indicate whether the soil is polluted by uranium or not. (2) Eight linear regression equationspassing the significance test with spectral angles as independent variables were obtained, covering all five experimental plants. The coefficient of determination R2 of 7 linear regression equations were >0.64, and R2 of 3 linear regression equations (ramie-seedling stage, Indian mustard-flowering stage and rape-bud bolting stage) were>0.81. Combined with other inversion effect evaluation indexes, it can be considered that leaf spectral angles can quantitatively indicate the degree of soil uranium pollution, but the function of the quantitative indicator varies with plant species and growth period. (3) There was a positive correlation between leaf spectral angles and uranium contents in soil. (4) The leaf spectral angles of ramie and Indian mustard at the seedling stage can be used to retrieve soil uranium content, which is an outstanding characteristic for indicating soil pollution status as early as possible through plant spectrum.
王卫红,罗学刚,武锋强,林 玲,李俊杰. 植物叶片光谱角对土壤铀污染的指示作用[J]. 光谱学与光谱分析, 2022, 42(04): 1313-1317.
WANG Wei-hong, LUO Xue-gang, WU Feng-qiang, LIN Ling, LI Jun-jie. Spectral Angles of Plant Leaves as Indicators of Uranium Pollution in Soil. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(04): 1313-1317.
[1] 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.
[2] YU Qing, WU Quan-yuan, YAO Lei, et al(于 庆, 吴泉源, 姚 磊, 等). Journal of Henan Agricultural Sciences(河南农业科学), 2018, 47(8): 54.
[3] Seongjoo Kang, Keum-young Lee, Eui-ik Jeon, et al. Spatial Information Research, 2018, 26(2):213.
[4] LIU Xiao-qing, LIU Yun-long(刘晓清, 柳云龙). Environmental Science & Technology(环境科学与技术), 2019, 42(5): 230.
[5] HE Jun-liang, CUI Jun-li, ZHANG Shu-yuan, et al(贺军亮, 崔军丽, 张淑媛, 等). Remote Sensing Technology and Application(遥感技术与应用), 2019, 34(5): 998.
[6] SHI Chao, HUANG Chao, LI Shu,et al(史 超, 黄 超, 李 书, 等). Bulletin of Geological Science and Technology(地质科技通报), 2020, 39(3): 202.
[7] YANG Ling-yu,GAO Xiao-hong,ZHANG Wei, et al(杨灵玉, 高小红, 张 威, 等). Chinese Journal of Applied Ecology(应用生态学报), 2016, 27(27): 1775.
[8] ZHU Ye-qing, QU Yong-hua, LIU Su-hong, et al(朱叶青, 屈永华, 刘素红, 等). Journal of Remote Sensing(遥感学报), 2014, 18(2): 335.
[9] YANG Ke-ming, SUN Tong-tong, ZHANG Wei, et al(杨可明, 孙彤彤, 张 伟, 等). Journal of Infrared and Millimeter Waves(红外与毫米波学报), 2018, 37(1): 80.
[10] Galal T M, Shedeed Z A, Hassan L M. International Journal of Phytoremediation, 2019, 21(14): 1397.