Effect of Chlorophyll Content & Solar Irradiance on Spectral Reflectance of Vegetation Canopies Acquired By Spectro-Radiometer

Authors : Tofayel AHAMMAD

Pages : 170-178

Doi:10.30897/ijegeo.958100

View : 11 | Download : 9

Publication Date : 2022-03-06

Article Type : Research Paper

Abstract :The aims of the study were: insert ignore into journalissuearticles values(i); to observe the effect of leaf chlorophyll content, Solar Irradiance and Normalized Difference Vegetation Index insert ignore into journalissuearticles values(NDVI); on spectral reflectance at Visibleinsert ignore into journalissuearticles values(Blue,Green,Red);, Near Infrared insert ignore into journalissuearticles values(NIR); and Short Wave Infrared insert ignore into journalissuearticles values(SWIR); spectrum for a given number of vegetation types including Rongon insert ignore into journalissuearticles values(Ixora Coccinea);, Hibiscus, Jhau, Grass and Togorinsert ignore into journalissuearticles values(Tabernaemontana Divaricata);.insert ignore into journalissuearticles values(ii); to investigate the relationship of Solar Irradiance with Normalized Difference Vegetation Index insert ignore into journalissuearticles values(NDVI); for the same number of vegetation types. This study used a five band hand-held spectro-radiometer “Multispectral Radiometer MSR-5” centered at wavelength 485nm, 560nm, 660nm, 830nm and 1650nm corresponding to bands 2, 3, 4, 5, 6 of Landsat 8 operational Land Imager insert ignore into journalissuearticles values(OLI); sensor. This spectro-radiometer provides solar irradiance and spectral reflectance values in the visible, NIR and SWIR spectrum which indirectly help to calculate Normalized Difference Vegetation Index insert ignore into journalissuearticles values(NDVI); for the given number of vegetation types. This study also used a Chlorophyll Meter insert ignore into journalissuearticles values(SPAD 502); to estimate chlorophyll concentration from the leaf of the vegetation types. The result shows that the value of the spectral reflectance correlated linearly with chlorophyll content at wavelength at 560nm and 1650 nm where the coefficient of determination R2 is 0.8761 and 0.6289 respectively. The spectral reflectance correlated inversely with NDVI at wavelength 485nm and 660nm where the coefficient of determination R2 was 0.5317 and 0.6191 respectively. This result also shows that solar irradiance relates inversely with chlorophyll content at wavelength 830nm where the coefficient of determination R2 was 0.8523.Lastly we have found that solar irradiance correlated inversely with NDVI where the coefficient of determination R2 was 0.7617.
Keywords : Normalized Difference Vegetation Index NDVI, , Leaf Area Index LAI, , chlorophyll content, Spectral Reflectance