灰漠土土壤全氮含量的高光谱特征分析及估测  

Hyperspectral Characteristic Analysis and Estimation of Total Nitrogen Content in Grey Desert Soil

作　　者：刘凡[1] 马玲[1] 杨光[1] 陈建华[1] 马雪莲[1] 王海江[1] 

机构地区：[1]石河子大学农业资源与环境系,新疆石河子832000

出　　处：《新疆农业科学》2017年第1期140-147,共8页Xinjiang Agricultural Sciences

基　　金：国际科技合作项目(2015DFA11660);国家大学生创新创业训练计划项目(201610759002);石河子大学校级项目(RCZX201522;SRP2016012);Fund project:gray desert soil;total nitrogen content;hyperspectral inversion

摘　　要：【目的】研究传统土壤全氮含量测定方法,解决复杂、耗时、耗力等问题。【方法】以新疆干旱区灰漠土为研究对象,运用经典统计学和光谱学相结合的方法,研究灰漠土土壤全氮含量的光谱反射特性,通过对原始光谱的数据变换和相关性分析,构建了土壤全氮含量的高光谱估测模型,并对模型进行对比和验证。【结果】土壤中全氮含量不同光谱反射特性趋势相近,土壤的光谱反射率在780、1 800和2 140 nm波长附近出现波峰,在1 910 nm附近有明显的波谷,土壤全氮含量与原始光谱反射率相关性较差。通过一阶微分处理后的光谱数据与全氮含量的相关性显著优于原始光谱和二阶微分处理,最大相关系数为0.819,达到极显著相关;利用一阶微分变换从中提取特征波段667和1 414 nm,建立土壤全氮含量的估测模型:Y=2 698.048 X667-1062.149 X1414-0.015,R2为0.75,对估测模型进行验证发现,R2为0.80,当全氮含量过大或过小时,模型估测偏差相对较大,总体预测精度较高。【结论】高光谱分析技术对土壤全氮含量的预测具有一定的意义,利用估测模型可以快速鉴定土壤全氮含量。[ Objective] To solve the traditional soil total nitrogen determination methods such as complex- ity, time -consuming, energy consumption and other issues. [ Method] Gray desert soil in Xinjiang was taken as our research object to study the spectral reflection characteristics of different soil total nitrogen and by using classical statistical and spectroscopy method, the remote sensing inversion models of soil total nitrogen were es- tablished and validated in the study area. [ Result] The results indicated that the content of total nitrogen in soil was similar to those of different spectral reflectance. The spectral reflectance of the soil appeared near 780, 1,800 and 2,140 nm wavelength. There was obvious absorption valley in the vicinity of 1,910 nm and the correlation between the total nitrogen content in soil and the original spectral reflectance was poor. The de- termination coefficients of first - order differential processing to original spectral reflectance were higher than o- riginal spectral reflectance and second order differential, the maximum R2 was 0.819, reaching a very signifi- cant correlation; By using the first order differential transform to extract the characteristic bands 667 and 1, 414 nm, the estimation model of soil total nitrogen content was established, they were： Y = 2,698. 048 X667 - 1,062. 149 X1414 - 0. 015. The R2 was 0.75 ; The estimation model validation found that the R2 was 0.80. When the total nitrogen content was too large or too small, the model estimation error was relatively large, and the overall prediction accuracy was quite high. The results has provided a theoretical basis to improve hyper- spectral remote sensing monitoring accuracy of soil nitrogen. [ Conclusion] High spectral analysis technique has certain significance for prediction of soil total nitrogen content and rapid identification of soil total nitrogen content by using the estimation model can be achieved.

关 键 词：灰漠土 土壤全氮含量 光谱反射特性 高光谱估测模型 

分 类 号：S158.2[农业科学—土壤学]