摘要
通过对野外采样取得的新疆古尔班通古特沙漠中的生物土壤结皮、裸沙和干枯植被进行反射光谱测定,揭示出在干燥条件下各类地物的反射光谱特征。进一步对经过均匀喷洒0.5和1.0mm水后的生物土壤结皮分别进行反射光谱测定,并对比分析了原始的和经水化实验后的生物土壤结皮光谱特征。依据生物土壤结皮的光谱特征,提出利用连续统去除技术估算生物土壤结皮覆盖度的方法,结果表明连续统去除光谱的负对数与生物土壤结皮盖度有很好的相关关系(r2=0.9907)。
Large areas of desert in arid and semi-arid regions are covered by biological soil crusts. Tracking the presence, distribution and disappearance of biological soil crusts is important for ecosystem management of desert regions and provides highly valuable information about desertification and climate change studies in arid and semiarid environments. The objective of the present paper is to analyze the unique reflectance spectral features of three types of biological soil crusts （moss, lichen and algae） relative to bare sand and dry plant. The measurements for the reflectance of bare sand, dry plant and biological soil crusts derived from the field survey were performed in the laboratory under dry condition. The reflectance of biological soil crusts after they were hydrated with 0. 5 and 1.0 rnm water respectively was also measured in the laboratory. It was found that the reflectance of crusts was much lower than that of bare sand throughout the Vis-SWlR region. Moreover, the reflectance of crusts exhibited a slightly flattening plateau between 600 and 750 nm, attributed to the absorption of photosynthetic pigments. Based on the spectral features of biological soil crusts, it was proposed that continuum removal technique could be used to retrieve the coverage of biological soil crusts. A significant correlation between the minus logarithm of the absorption depth of the continuum removal spectra and the coverage of biological soil crusts was found （r^2- 0. 990 7）. The liquid-water hydration experiment demonstrated that the absorption of photosynthetic pigments was strengthened after hydration, making the detection of biological soil crusts much easier.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2008年第1期28-32,共5页
Spectroscopy and Spectral Analysis
基金
遥感科学国家重点实验室开放基金项目(SK050001)
中国科学院知识创新工程重要方向项目(KZCX3-SW-343)
教育部留学回国人员科研启动基金项目资助
关键词
生物土壤结皮
反射光谱特征
古尔班通古特沙漠
连续统去除
Biological soil crust
Reflectance spectra characteristics
Gurbantonggut desert
Continuum removal
