Analyzing Directional Urban Sprawl from 1978 to 2023 Using Shannon Entropy Analysis on Landsat Imagery: A Case Study in Ramadi City, Iraq

Abstract

The expansion of contemporary cities in developing countries poses a significant challenge for decision-makers involved in urban planning and management. Ramadi, recognized as one of the largest cities in Anbar Governorate and serving as its administrative center, necessitates close monitoring of the changes resulting from urban expansion and the encroachment of its urban sprawl into neighboring areas, a phenomenon referred to as 'urban captivity.' To address this, the study employs Shannon’s entropy model, offering a novel approach to examining city expansion using remote sensing data. This research focuses on the urban expansion of Ramadi, utilizing Landsat satellite data spanning four decades (1978, 2000, 2010, 2023). Digital processing and image classification techniques were employed to create four urban maps, enabling the tracking of urban growth patterns over the specified time periods through remote sensing software and geographic information systems. The findings reveal significant shifts in the city's structure, characterized by a notable increase in residential areas accompanied by a significant decrease in agricultural lands. In 1978, agricultural lands within the city's boundaries accounted for 19.99% of the total analyzed area of 139 km², decreasing to 9.17% by 2023. The data also indicates a gradual increase in growth rates from 1978 to 2000, amounting to 0.76, followed by a qualitative surge in urban growth, reaching 5% in 2023. Notably, horizontal urban expansion emerges as the dominant trend over vertical development.