| Abstract: | Abstract The vegetation has been poisoned by gold in the western Guangdong-Hainan region. The gold content of the leaves there is as high as 10-1961 times the abundance, the chlorophyll content is 10%-30% lower than that of the vegetation in metamorphic terrains and 10%-20% higher than that in granite terrains, and the carotenoid content is 10%-44% lower than the background value. The water content of leaves is 10% to 20% lower than the background value. The cells of leaves are deformed and broken. The leaf surface shows colour spots and becomes yellow or dark green. The spectral reflectance of the leaf surface is 5%-30% higher than the background value; the spectral shape has shifted 5-15 nm to the short wavelength. The gray scales of eanopy on images of Landsat TM and airborne imaging scanner (AIS) are 10%-100% higher than the background values. On Landsat TM and AIS false colour images, plants poisoned by gold display a yellow color, which disinguishes them from background plants. According to the spectral and image features of gold biogeochemical effects, the author has constructed a gold information system and expert prediction system, and thus two gold target areas and two gold prospect areas have been identified rapidly, economically and accurately in the western Guangdong-Hainan region which is extensively covered by vegetation. |
