基于TM影像的荒漠绿洲交错带土壤有机质含量反演模型

选取Landsat TM影像的光谱反射率（R）、反射率之倒数（1/R）、反射率倒数之对数（lg（1/R））、反射率一阶导数（FDR）、波段深度（D）等5种光谱指标，分别建立了奇台县土壤有机质（SOM）含量的反演模型，并利用F检验来验证模型的显著性。结果表明：用各光谱指标建立的土壤各层和不同深度SOM含量的反演模型精度值由低到高的顺序均为lg（1/R）<R<1/R<FDR<D，以D反演SOM含量的模型效果最好，且对10～20 cm的SOM含量的反演精度最高，适用于对研究区SOM含量的反演，FDR的反演效果次之，1/R和R的模型精度一般，而lg（1/R）的模型精度最差；各层拟合模型的反演精准度由低到高的顺序为50～60 cm <40～50 cm <30～40 cm <20～30 cm <0～10 cm <10～20 cm，不同深度反演模型的优劣为0～60 cm <0～50 cm <0～40 cm <0～30 cm <0～10 cm <0～20 cm。

Inversion Models of Soil Organic Matter in Oasis-Desert Ecotone Based on TM Image Reflectance

The image spectrum reflectance (R), spectrum reciprocal (1/R), the logarithm of reciprocal spectrum lg(1/R), first derivative reflectance spectrum (FDR) and spectrum band depth (D) of five spectral index were selected to establish soil organic matter (SOM) inversion models, and the response characteristics of TM image of Qitai county are analyzed, the F test was used to validate the model significance. It turns out that: The accuracy value of the inversion models established by the five indicators on the soil layers and different depths SOM content are various, and the order from low to high is: lg(1/R)< R< 1/R< FDR< D. The model accuracy of D is the best for inversion of SOM content, and achieves a good standard for the monitoring of SOM content (10-20 cm). The model accuracy of FDR is good, and 1/R，R are not good. The model accuracy of lg(1/R) is the lowest in predicting SOM content. The precision order of the soil layers models is: 50-60 cm< 40-50 cm< 30-40 cm< 20-30 cm< 0-10 cm< 10-20 cm, and for the different soil depths models is: 0-60 cm< 0-50 cm< 0-40 cm< 0-30 cm< 0-10 cm< 0-20 cm.