Water Management Problems Associated with Urban Sprawl in Gharbia Governorate, Egypt Using Remote Sensing and GIS

Abstract

Urban sprawl is one of the major problems that evolved in the Nile Delta as a result of the deficiency in the security system after the 25^th of January revolution in Egypt in 2011. This problem not only threatens the limited fertile lands but also influences the water distribution regime in these areas. For this purpose, three types of satellite images were employed; i.e. Landsat Thematic Mapper (TM) 1990, Egyptsat-1 2010 and SPOT 5–2011, to study the urban sprawl and its impact on the agricultural land and water distribution management in Gharbia Governorate. Maximum likelihood supervised classification and post classification change detection techniques were applied for monitoring the urban sprawl in this study area. The accuracy of the classification results was assessed using a 1992 topographic map. Using ancillary data, visual interpretation and expert knowledge of this area through GIS further refined the classification results. Combining the soil and land capability maps, on one hand, and the urban thematic layers, on the other hand, using GIS, made it possible to point out the risk of urban expansion on the expense of the highly capability class. During the period of (1990–2011), the highly capable soils decreased from 1710.75 km² in 1990 to 1610.22 km² in 2011. A total of 1.5 km² of urban areas was recently constructed after 2010 inside the 500 m buffer zone around the (10–25 m) width canals. A water management index is calculated which decreased as a result of the urban sprawl on a 500 m buffer zone around the irrigation canals.