The Interplay between Spatial Urban Expansion and Morphologic Landscapes East of Cairo, Egypt Using Time Series Satellite Imagery

Abstract

This study aims to monitor the magnitudes, rates, and directions of spatial urban expansions east of Cairo and their interactions with the initial morphologic landscapes. The approach relies on using CORONA satellite images acquired in 1969 with fine spatial resolution and time series images of Landsat and ASTER from 1984 to 2020. The CORONA images enable retrieval of the initial morphologic components, whereas the Landsat and ASTER images enable the spatial urban expansions to be mapped. The magnitudes of spatial urban expansions have been massive, in the order of 165 km2. These expansions have occurred through four main temporal phases with different spatial extents, rates, and directions in response to common urban policies and socioeconomic settings. Assessing the interactions between urban expansions and the morphology of watersheds in the study area indicates that the directions of urban expansion have been opposite to the geospatial orientations of the watersheds. In addition, significant urban areas in the order of ~8 km2 are under the direct threat of flash floods because they are misplaced within the valley floors of the studied watersheds. The study concludes that successful spatial urban expansion should consider the morphologic characteristics of the initial landscape for the purpose of maximizing interests and avoiding or reducing potential hazards against urban settlements.

Using CORONA Imagery to Study Land Use and Land Cover Change—A Review of Applications

“…As the mission of CORONA was to provide images, especially of the Soviet Union and China [51], these two countries were featured in most LULC studies in which CORONA data were used. Our results showed that except for present-day Russia and China, CORONA imagery was also commonly used in India and Nepal; the Middle East (Iraq, Iran and Syria); Northern and Western Africa (Egypt, Mali and Senegal); and Central and Eastern Europe (Poland and Romania) [26,28,30,[42][43][44][52][53][54][55][56][57][58]. Some of these countries (e.g., Poland and Romania) have good coverage of CORONA imagery due to the goals of the program and the importance of the countries during the Cold War era [59][60][61].…”

“…Another frequently studied category is built-up areas in urban and peri-urban settings. For example, Shalaby et al [55] studied the directions of urban expansion and confirmed that the high spatial resolution of declassified images was sufficient to accurately map initial morphologic features. Pan et al [70] monitored the urban expansion of Xining City in China and confirmed the capability of CORONA and its resolution to quantify urban expansion.…”