Temporal Variability Analysis of Vegetation Cover in Diyala, Iraq using Multi-Index Remote Sensing: A Case Study

Abstract Vegetation indices (VIs) are crucial instruments for evaluating and tracking vegetation temporal changes using satellite data to promote sustainable land and environmental management. Diyala governorate in central Iraq is a strategically significant area that can be used as a model to evaluate vegetation dynamics and environmental change due to its various biological regions and semi-arid weather. Thus, this research aims to monitor vegetation cover in Diyala region of Iraq using satellite images during the period from 2000 to 2024. Two types of Landsat images, Enhanced Thematic Mapper (ETM) and Landsat 8, were used. To extract vegetation cover in the study area, multiple indices were used, including Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Modified Soil Adjusted Vegetation Index (MSAVI), Soil Adjusted Vegetation Index (SAVI), and Transformed Normalized Difference Vegetation Index (TNDVI). The results illustrated that there was an increase in vegetation cover from approximately 12% to 62% during the period from 2000 to 2024, respectively. The water area increased approximately from 2% to 4%, while bare lands decreased approximately from 86% to 34% for the years 2000 and 2024. The percentages of vegetation cover, extracted from VIs, were closer to the results of supervised classification.