Urbanization and flood risk analysis using geospatial techniques

Area of Science:

• Environmental Science
• Urban Planning
• Disaster Management

Background:

• Urbanization significantly alters land use and land cover, impacting hydrological systems.
• Accra has experienced rapid urban growth, raising concerns about increased flood vulnerability.
• Understanding the link between urban expansion and flood disasters is crucial for effective urban planning.

Purpose of the Study:

• To investigate the relationship between urbanization and increased flood disasters in Accra.
• To map and analyze land use/land cover changes from 1991 to 2015.
• To correlate urbanization patterns with the frequency and intensity of flood events.

Main Methods:

• Analysis of land use/land cover changes using remote sensing data from 1991 to 2015.
• Review of historical flood event data for Greater Accra.
• Statistical analysis to establish the relationship between urbanization patterns and flood disaster trends.

Main Results:

• Urban land use/land cover increased by 95.51% (1991-2002) and 129.14% (2002-2015).
• Urbanization occurred in an unplanned manner, with significant development encroaching on waterways.
• Flood disaster events showed an increasing trend from 1991 to 2015, with recurring events in some years.

Conclusions:

• Unplanned urbanization and encroachment on waterways are key drivers of increased flood disasters in Accra.
• Evidence-based planning is essential to mitigate flood risks associated with urban development.
• Coordinated efforts among urban planners, policymakers, and flood managers are needed to address the growing flood problem.