MONITOR CHANGES IN THE SPECTRAL INDICES VALUES OF SOIL SURFACE AND THEIR SPATIAL DISTRIBUTION USING REMOTE SENSING DATA

The study aims to monitoring the changes occurring in the values and area of the ground cover of the soil surface during the period 2006-2019 represented by water cover, wet areas, vegetation cover and soil erosion by applying mathematical relationships of a set of spectral indices specialized in studying soil and water. The spectral indices used in the study (EMI, NDWI, TCW and TCG). The results of the study showed a decrease in the values and area of the water cover represented by marshes, swamps and rivers due to the decrease in water levels and the increase in the phenomenon of drought in southern Iraq during the period 2006-2019, in addition to a great possibility to distinguish dry and barren lands from green lands, wet soils and droughts for agricultural uses. It can be concluded that the use of the TCG indices is important in diagnosing the vegetation cover in the study area, which was characterized by its content of plants, palm trees and vegetables, especially the banks of rivers and some reed and sedge plants in the marsh areas. Therefore, the study area was characterized by its low values and green areas and this is an indicator of the weak agricultural investment in it except for some regions. The results of the study also showed that there were levels of wind erosion during the period 2006-2019, ranging between very severe and low, the Dominance of very severe erosion throughout the study area, especially in the year 2006, where the area exposed to wind erosion amounted to about 4325.58 km(2), with a rate of 90.57%.