Study calcareous soils behavior in different climatic conditions based on their spectral signature

Abstract

Lime and gypsum are among the compounds that give clear indicators when monitored by remote sensing devices and techniques, and since they are present in agricultural soils significantly in arid and semi-arid regions, lime was considered one of the indicators that can be monitored in the soil. Accordingly, four areas were chosen to study the spectral reflectivity of their surface soils under somewhat different climatic conditions, which are the northeast of Dohuk, Al Sherekhan, the village of Balak Qout, and the University of Mosul. They represent the soils of agricultural areas. Representative samples of the soil were taken for each study area, and the value of calcium carbonate was measured, and three levels of soil particles were made for each sample, which are grinding soil in the form of powder, and aggregates of soil particles with a diameter of 2 mm, and aggregates of soil particles with a diameter of 4 mm. After that, the reflectivity of the flat surfaces of these samples was measured using a spectrometer. The results showed a superiority in the spectral reflectivity values between the sizes of the diameters of the soils, as the highest reflectivity of the soil was of soft sizes, then the largest size, then the largest, and that the carbonate content had a clear effect in raising the spectral reflectivity ratios in all locations with the overlap in the amount of reflected rays due to the dispersion that occurs, due to the surface roughness of the samples with larger diameters.