Spectral indicators for Assessing the extent of Land use and its Relation to Organic carbon in Desert palm orchards soils in Karbala- Iraq

Abstract

Remote sensing techniques involve acquiring and interpreting information about objects or areas from a distance, typically using satellite or aerial imagery. This study aimed to monitor land cover changes in central Iraq and investigate the impact of the age of organic carbon in the soil on vegetation dynamics using remote sensing techniques. The research focused on the Fadak palm farm project of the General Secretariat of the Holy Husseiniya Shrine. Satellite imagery for the years (2017) and (2022) was digitally processed and visually analyzed after applying radiation and spatial enhancements. Spectral evidence was identified to assess temporal and spatial variations in the study area. Two indicators were used: the Normalized Difference Vegetation Index (NDVI) and the Soil-Adjusted Vegetation Index (SAVI) to evaluate modified vegetation cover due to soil conditions. The percentage of variation in these spectral indicators between (2017) and (2022) was calculated. The results indicated the presence of temporal and spatial variations, reflecting the natural heterogeneity of land covers applying a Geographic Information System (GIS). Furthermore, the calculations revealed a significant positive correlation between NDVI values and organic carbon values. This correlation was assessed through gradient and trend factors derived from the NDVI and SAVI calculations. The relationship between the percentage of organic carbon in the soil and spectral evidence at the near-red wavelength was evident in the variation in vegetation cover density. To classify the satellite data and map different land cover types, the directed classification method in (ArcGIS V10.8) was employed. The classification results aligned with the evidence provided by NDVI and SAVI, confirming the presence of vegetation cover classified as low to high density, as well as barren land and water bodies.