The Characteristic Analysis of Canopy Spectrum and Moisture Content of 10 Typical Arid Desert Plants

Plant water is a main factor to affect physiological and biochemical indexes of plants like photosynthesis, respiration, and biomass and so on. The investigation of plant water content is an important part of vegetation research. The study of the relationship between water content and canopy spectrum of typical desert plants by hyper spectral has great significance for remote sensing monitoring of vegetation in arid desert areas. The canopy spectral curves of 10 typical desert plants were determined by ASD portable ground spectrometer in this study. The correlation coefficient method and vegetation index method were used to analyze the spectral characteristics of different desert plants and their relationship with canopy moisture content. The results show: 1) the reflectance curve of desert plants has the general characteristics of green plants in the visible-near-infrared band, with obvious "green peak" characteristics and "red edge effect". 2) In the three wavebands of 954-973 nm, 1184-1198 nm and 1440-1462 nm, desert plants have obvious water absorption valleys. Among them, the correlation coefficient between spectral reflectance and water content in the 1440-1462 nm band is greater than 0.8, and they have strong linear correlation. 3) WBI (Water Band Index), NDWI (Normalized Difference Water Index), NDII (Normalized Difference Infrared Index), MSI (Moisture Stress Index) were significantly correlated with plant water content (P<0.05), and the measured values of canopy moisture content index and vegetation moisture have high consistency and can reflect the change of moisture content of desert vegetation.