Change detection and urban expansion of Port Sudan, Red Sea, using remote sensing and GIS.

During the last two decades, Port Sudan City has witnessed major environmental stresses resulting from urban expansion and port extensions. This research aims at analysing land water changes (LWCs), land use land cover (LULC) changes and urban expansion of Port Sudan using remote sensing and GIS. For that purpose, an integrated remote sensing and GIS approach was designed to analyse two Enhanced Thematic Mapper (ETM) and an Operational Land Imager (OLI) Landsat images covering the period from 1999 to 2018. LWCs were detected using mathematical remote sensing and GIS-based procedures, while LULC changes were analysed through a post-classification comparison (PCC) approach using a support vector machine (SVM) classifier for classification. Major detected LWCs include landfill activities in the port area and north lagoon of Kilo Tamanya, and dredging activities in Khor Mog. Areas gained by landfill may have improved the port and transport functions but buried coral reefs and caused environmental problems as well. Furthermore, the urban areas were twice doubled, which was mostly rapid and uncontrolled, adding more pressure to the already stressed services and administrative sectors. Threats to the agricultural and mangrove areas were also analysed. The agricultural and mangrove areas were decreased by 40% each, which has been shown to have negative impacts on society, food security and biodiversity. Sadly, the lost agricultural lands were changed into bare soil, slums and other industrial uses. In contrast, mesquite forests were naturally increased by 74%. Mesquites have a major role in combating desertification and providing energy for domestic use. The driving forces and constraints of the urban expansion were highlighted. The change information provided by the applied approach will support decision-makers in adopting integrated and compatible land and coast management planning in the studied coastal city.