土壤氧化铁的高光谱响应研究

Influence of Soil Iron Oxide on VNIR Diffuse Reflectance Spectroscopy

通过分析野外采集的13个土种的不同氧化铁含量原始土样和人工配制不同氧化铁含量土样的高光谱特征,研究了氧化铁对土壤反射率、土壤线参数、土壤有机质高光谱特征、土壤反射率光谱曲线形态的影响。研究结果表明,随氧化铁含量的增加,350～570nm波段反射率降低,570～2 500nm波段的反射率增加,氧化铁去除量与反射率变化量之间的相关性不明显;氧化铁含量与土壤线斜率呈线性负相关,与截距呈线性正相关,且均达到极显著相关水平,表明利用土壤线参数反演氧化铁含量具有可行性;在622～851nm波段,氧化铁对有机质的高光谱特征具有明显的抑制作用;通过去包络线和统计F值与光谱角值表明,氧化铁对土壤反射光谱曲线形态有影响。

The influences of iron oxide on soil reflectance, soil line parameter, organic matter spectral characterization and the shape of soil reflectance spectra were studied in the present paper with thirteen samples in several soil types, which covered a range of iron oxide content obtained from various combination of original and irorrremoving samples. The results highlight that （1） a decrease on 350-570 nm and an increase on 570-2 500 nm were showed in the reflectance spectra with increasing iron ox-ide content. However, there was no significant correlation between iron oxide and spectral reflectance quantitatively; （2） iron oxide content had a negative linear correlation with soil line slope and a positive linear correlation with intercept, both were sig-nificant, which illustrated the feasibility of iron oxide prediction using soil line parameter; （3） the spectral characteristics of soil organic matter could be covered by iron oxide on 622-851 nm; （4） iron oxide in soil had influence on the shape of reflectance spectra after continuum removal and calculating statistical F and spectral angle.