The Nature of the Effect of the Physiographic Location on the Spectral Behavior of Soil Horizons and the Distribution of Vegetation in Central and Northern Iraq

Abstract

Abstract Three soil sites in central and northern Iraq were chosen to represent the nature of three physiographic units, namely, the mountainous unit, the undulating unit, and the river basin unit, to study the effect of unit variation on the nature of soil pedological properties and its spectral behavior. The results reached a diagnosis of the nature of the variation in the characteristics of the soil represented by the variation of the morphological characteristics represented by the difference of the wavelength if 5YR prevailed for the elevation within the mountainous unit and the soil color was dark reddish-brown, while in the rest of the units it was 10YR and the predominance of the light color was affected by the different physiographic units, which was reflected in the diagnosis of the surface diagnostic horizon Mollic horizon Representing the mountainous unit, and subsurface horizon representing the Argillic horizon, and Ochric horizon, and calcic horizon within the undulating unit, as well as the high content of organic matter and iron oxides in the mountainous unit, and the values reached 34.1 grams.9.02 as well as the variability of the soil separations, as the sand separation increased in the amount representing the unit of the river basin and reached 486 g.kg and The lowest value of the spectral reflectivity was in the region representing the mountainous physiographic unit, and it reached 35% for the subsurface horizon, while the reflectivity in the rest of the units rose to 62%. Absorption bands were diagnosed at wavelengths 1400 and 1900 nm. Near-infrared is represented by wavelengths 1750-2000 and at wavelengths 2000-2500. The values of the natural variation index for plants were 0.30 with an area of 4357 km2.