新疆博州典型荒漠植被光谱反射特征分析

Analysis on Spectral Reflectance Characteristics of Typical Desert Vegetation in Bozhou of Xinjiang

针对博州光谱研究尚少和对光谱一阶导数缺乏定量描述的问题,补充分析了博州光谱,提出了对光谱一阶导数定量描述的方法。以博州为研究区,在2014年7月下旬对锦鸡儿、梭梭、红柳、白刺、萱麻、沙拐枣等地物进行野外光谱数据采集,并对光谱数据进行平均、平滑和一阶微分等处理;分析了不同植被之间、同种植被之间的光谱特征,并对光谱进行对比分析、红边参数特征分析等研究。研究表明：这6种荒漠植被在可见光波段的380~700nm之间的反射率均较低,没有超过15%;除了在480nm和680nm附近有吸收谷外,在970nm附近也有一个吸收谷,并且＂蓝谷红移＂现象比较明显;红边特征比较明显,其中萱麻的红边特征最明显;在近红外波段1 100nm附近反射率很高,平均峰值达到70%以上。所得结论对于博州荒漠地区光谱特征基础研究、荒漠植被生长情况,以及荒漠化程度的监测具有重要意义。

As the lack of research into spectra for Bozhou and the quantitative description of first derivative spectrum,we made additional analysis of the spectra for Bozhou and put forward a quantitative method to describe the first derivative spectra.In the research area of Bozhou in late July 2014,the spectral data of Caragana,Haloxylon,Tamarix,White thorn,Ramie,Calligonum and other surface features was collected and processed by average,smooth,first derivative and other methods.Then,the study analyzed the spectral characteristics between the same vegetation and among the different.Moreover,the comparative analysis of the spectrum,red edge parameters characteristic,etc.was also conducted.The results suggested that the reflection rate of six desert vegetation was low,less than 15%,between 380~700nm visible wavelength range,and was high around near infrared 1 100 nm with average peak more than 70%;besides the absorption valleys located at around 480 nm and 680 nm,they also had one near 970 nm,and the ' blue valley red shift' phenomenon was more obvious;the characteristics of red edge were remarkable,with the maximum appearing in the ramie.This research on the spectral characteristics has important significance for the surveillance of desert vegetation growth and the extent of desertification in Bozhou desert regions.