Using Light Reflectance to Assess Phenology Stresses Impacted by Urban Heat Island in Karbala
Journal of Southwest Jiaotong University
The influence of Urban Heat Island on urban phenology assessment beside the impact of climate change on seriously deteriorated Mimosa (Albizia julibrissin) leaves. This research focuses on the light reflectance from Mimosa leaves to assess the water stress, nitrogen deficiency and serious damage. Healthy leaves absorb blue and red light and reflect green light. Light absorption beyond WB 5 (1150– 1300 nm) is high due to leaf water content. The spectrum regions wherein relatively little
... ely little absorption will occur can be seen in the range from 500 to 600 nm (WB1 and WB2) and the region from 700 to 1200 nm (WB4 and WB5). When waves are longer than 1200 nm, water vapor absorption rises very steeply, while absorption of the red and blue regions of the visible spectrum is very strong. When Leaf Area Index increases the reflectance in chlorophyll, absorption decreases. There is a sharp increase in WB3 to WB5 and in WB4 to WB6 reflection of Leaf Area Index 0.52-1.0 and 1.0-1.5 respectively and a decrease in reflectance beyond WB6. With a natural background of trees, light reflectivity was compared under wet and dry soil conditions. Red and near infrared affected the reflectivity due to its critical to the land cover.