吉一涛, 舒清态, 黄田, 谢福明, 刘延, 吴秋菊. 基于光谱特征参量的高山松叶片氮素含量估测模型研究[J]. 西南林业大学学报, 2018, 38(3): 151-156. DOI: 10.11929/j.issn.2095-1914.2018.03.022
引用本文: 吉一涛, 舒清态, 黄田, 谢福明, 刘延, 吴秋菊. 基于光谱特征参量的高山松叶片氮素含量估测模型研究[J]. 西南林业大学学报, 2018, 38(3): 151-156. DOI: 10.11929/j.issn.2095-1914.2018.03.022
Yitao Ji, Qingtai Shu, Tian Huang, Fuming Xie, Yan Liu, Qiuju Wu. Spectral Characteristic Parameter-based Models for Foliar Nitrogen Content Estimation of Pinus densata[J]. Journal of Southwest Forestry University, 2018, 38(3): 151-156. DOI: 10.11929/j.issn.2095-1914.2018.03.022
Citation: Yitao Ji, Qingtai Shu, Tian Huang, Fuming Xie, Yan Liu, Qiuju Wu. Spectral Characteristic Parameter-based Models for Foliar Nitrogen Content Estimation of Pinus densata[J]. Journal of Southwest Forestry University, 2018, 38(3): 151-156. DOI: 10.11929/j.issn.2095-1914.2018.03.022

基于光谱特征参量的高山松叶片氮素含量估测模型研究

Spectral Characteristic Parameter-based Models for Foliar Nitrogen Content Estimation of Pinus densata

  • 摘要: 以我国西部高海拔地区特有树种高山松为研究对象,基于ASD便携式地物光谱辐射仪测定高山松叶片光谱,结合叶样氮素含量的实验室分析结果,利用相关分析法筛选与叶样氮素含量具有极显著相关性的光谱特征参量,分别采用回归曲线法和K-邻近距离(KNN)法构建高山松叶片氮素含量的参数和非参数估测模型,通过精度检验对2种方法及其构建模型进行对比分析。结果表明:在参数模型中以红边面积与蓝边面积比值(SDr/SDb)为自变量构建的二次函数模型估测效果最好,其决定系数(R2)、均方根误差(RMSE)和相对误差(RE)分别为0.627、0.12 g/100 g和4.75%;采用KNN法构建的非参数模型估测效果更好,其R2、RMSE和RE分别为0.856、0.12 g/100 g和5.43%。说明相对于传统的参数模型,KNN法构建的非参数模型在高山松氮素含量估测方面表现出更优越的估测能力。

     

    Abstract: Pinus densata, the endemic tree species in high altitude area of Southwest China, was chosen as the test cultivar, and the spectral reflectance of foliage was measured by ASD Field Spec 3 Spectrometer. The spectral characteristic parameters highly significantly correlated with the foliar spectral reflectance and foliar nitrogen content were selected by Pearson Correlation Analysis, combined with the results of laboratory analysis of foliar nitrogen content. Parametric and nonparametric models for estimation of foliar nitrogen content of P.densata were established by employing regression analysis and KNN, the precision of the models were tested and compared by the independent sample. The results indicated that the best parametric model was the quadratic model using SDr/SDb as a variable, in which the values of R2, RMSE and RE were 0.627, 0.12 g/100 g and 4.75% respectively, and that the non-parametric model constructed by KNN had better effect, and the values of its R2, RMSE and RE were 0.856, 0.12 g/100 g and 5.43% respectively. These results suggested that the nonparametric model established by KNN showed better predictive ability than the traditional parametric models for nitrogen content estimation of P.densata.

     

/

返回文章
返回