Analysis of land use/ land cover characteristics by different indexes and remote sensing methods: A case study of Erbil city

This study addresses concerns about urban sprawl in developed countries, focusing on the major metropolitan city of Erbil in northern Iraq. Rapid urbanization and economic growth in Erbil have led to environmental challenges, including land preservation issues, air and noise pollution, and a decline in annual precipitation. Using remote sensing data from Landsat, MODIS, and Sentinel-2 satellites, we investigate the spatio-temporal variation of land use and land cover (LULC) over 30 years (1991-2021). Employing classification techniques and various vegetation indices, such as NDVI, GNDVI, NDWI, and LST, we assess urban expansion and its impact on the ecosystem. Our findings reveal a 16.55% increase in urban expansion and a decline in agricultural land cover from 4.94% (1991) to 2.59% (2021). The predictive model indicates a further 6.92% increase in built-up areas by 2026, with 6.83% of barren land converted due to urban expansion. Correlations between spectral vegetation indices, particularly NDWI and LST, and the Standardized Precipitation Index (SPI) highlight significant LULC changes. Notably, Landsat-8 and Sentinel-2 data prove more effective than MODIS in monitoring urban expansion and its environmental impact. This study underscores the potential of time-series data for detecting and mitigating urban sprawl, providing valuable insights for future LULC trends and proposing policies to curb the adverse effects on agriculture and the environment in Erbil city.