Abstract
Cities in developing countries are urbanising at a rapid rate, resulting in substantial pressures on environmental systems. Among the main factors that lead to flooding, controlling land-use change offers the greatest scope for the management of risk. However, traditional analysis of a “from–to” change matrix is not adequate to provide information of all the land-use changes that occur in a watershed. In this study, an in-depth analysis of land-use change enabled us to quantify the bulk of the changes accumulating from swap changes in a tropical watershed. This study assessed the historical and future land-use/land-cover (LULC) dynamics in the River State region of the Niger Delta. Land-use classification and change detection analysis was conducted using multi-source (Landsat TM, ETM, polygon map, and hard copy) data of the study area for 1986, 1995, and 2003, and projected conditions in 2060. The key findings indicate that historical urbanisation was rapid; urban expansion could increase by 80% in 2060 due to planned urban development; and 95% of the conversions to urban land occurred chiefly at the expense of agricultural land. Urban land was dominated by net changes rather than swap changes, which in the future could amplify flood risk and have other severe implications for the watershed.
Highlights
Cities are urbanising at unprecedented rates, resulting in profound and unintended impacts on landscapes and urban hydrology [1,2,3,4]
Greater Port Harcourt (GPH) city in Nigeria is a compelling example of rapidly urbanising cities in Africa, with a delicate and dynamic wetland environment that is very sensitive to flooding [11]
Based on the change detection analysis, this study reveals that the urban land cover experienced significant growth in extent of over 300% between 1986–2003, increasing from 135 km2 to around
Summary
Cities are urbanising at unprecedented rates, resulting in profound and unintended impacts on landscapes and urban hydrology [1,2,3,4]. There is a wide consensus that cities in Asia and Africa are more vulnerable to the effects of flooding due to increased urbanisation, climate change, poor planning, weak regulations, and poor adaptive capacity [2,8,9,10]. There is a critical need to understand the historical patterns of land-use change, the extent of future urbanisation and their resulting impacts on urban landscapes in these regions to inform flood risk management strategies.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
