Monitoring Spatial and Temporal Changes of Urban Growth in Dakahlia Governorate, Egypt, by Using Remote Sensing and GIS Techniques.

Document Type : Research Studies

Authors

1 Department of Soil Science, Faculty of Agriculture, Mansoura University, Egypt

2 Department of Building and Construction Engineering, University of Technology, Baghdad, Iraq. Researcher at Department of Public Works, Faculty of Engineering, Mansoura University, Egypt

3 Public Works Engineering, Geodesy, faculty of Engineering, Mansoura University

Abstract

Dakahlia is one of the important agricultural governorates in the Middle of Nile-Delta, Egypt. Fertile agriculture areas in the Nile-Delta of Egypt are constantly deteriorating mainly due to urbanization. Remote sensing and GIS technology have proven their great ability to explore the problems of urbanization and their impacts on agricultural lands. The main objectives of this study were to provide an accurate assessment of urban areas in Dakahlia Governorate and to study the impact of urbanization on agricultural lands during the period from 1984 to 2014. Accordingly, Landsat TM images in 1984 and ETM+ in 2002 and 2011 and OLI-TIRS in 2014 were used to study spatial and temporal changes in both urban and agricultural lands in Dakahlia Governorate. Normalized difference vegetation index (NDVI), Normalized difference built-up index (NDBI) and soil adjusted vegetation index (SAVI) were used to extract urban versus agricultural lands from these multitemporal Landsat images.  The results indicated that the annual increase in urban lands was about 2.54 km2 per year during the period from 1984 to 2002 and about 4.01 km2 per year during the period from 2002 to 2011. However, the rate was highly increased by about 47.99 km2 per year during the period from 2011and 2014. It was also observed that the increase in urban areas was clustered around old cities and villages before 2011; however it took a random pattern after 2011. Accuracy assessment of the studied indices indicated that the NDBI has the highest accuracy.  It could be concluded that urban encroachment over the fertile agricultural lands is the most serious process that result in fertile land degradation in Dakahlia Governorate.

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