黑河流域土壤光谱特性与响应原理分析

Spectrum Characteristics and Response Principle of Soil in Heihe River Basin

采集黑河上游排露沟小流域的多个土壤剖面的84个土壤样品,自然风干处理后,利用美国ASD光谱仪获得土壤的反射光谱曲线,分析其光谱特性与响应原理。结果显示:个别土壤曲线表现出与众不同的波浪状形态;有机质对反射率的影响在600～800nm最为明显,当其质量分数小于20g/kg时,表现出明显的陡坎状凸起;土壤反射率随粉粒含量的增加而升高;1 414和1 919nm附近的吸收谷是由OH伸缩振动的一级倍频和二级泛频产生,2 210和2 350nm附近是由金属-OH和CO32-倍频或合频引起,包络线去除后,420,490,540,660和900nm处表现出明显的吸收谷,是因为存在铁氧化物。

A total of 14 profiles and 84 soil samples were taken from 7 altitude gradients from 2 600—3 800 m and 13 vegetation types in Pailugou Basin.Air-dried soil samples were scanned and reflectance of samples was recorded for 350—2 500 nm using ASD hyperspectral sensor.The spectral characteristics and response principle were analyzed,and the results showed that： the change trend of most of spectrum is consistent,except for several spectral curves;the band,which SOM mainly affects on soil reflectance,was in 600—800 nm;when the SOM content was less than 20 g/kg,the spectral curve had an obvious convex in the region;the soil reflectance increased with the decrease of sand content and the increase of silt content at 400—1 300 nm,and decreased with the increase of clay content;the absorption vales appeared in 1 414 nm and 1 919 nm are caused by OH,and that in 2 210 nm and 2 350 nm was caused by-OH and CO32-;the absorption peaks appeared in 420 nm,490 nm,540 nm,660 nm and 900 nm after continuum removal because there are iron oxides in soil.