Geospatial Management of Urban Marginal Lands for Disaster Risk Reduction in Nigeria’s Confluence Town

Abstract

The current trends in global urbanization as summarized by UNDP stands at 2.4 billion in 1990 and will rise to 3.2 billion in 2000 and 5.5 billion in 2025. The developing countries' share (including Nigeria) in these totals - 63 per cent in 1990 - will rise to 71 per cent in 2000 and 80 per cent in 2025. There is crisis in the mismatch between urban land demand and supply; hence the encroachment on marginal lands. The geographical location of Lokoja that is sandwich between Mount Patti and Niger-Benue Confluence exacerbate the land use pressure crises. Critical land area development in Lokoja is tending toward complex ecological problems. This study is therefore aimed at examining the urban marginal land encroachment using spatial analysis for disaster risk reduction in the town. Landsat and Nigeria SatX imageries were acquired and analyzed using ArcGIS 10.0 and Tera-Incognitia 2.42; Suffer 11 was used for the DEM production. This was complemented with Google Earth for the field work. The study revealed that a total of 3.65km2 and 0.14Km2 of vegetation and marshlands respectively, were lost annually within the 17 years period. It was also observed that a total of 657 buildings were constructed on marginal lands in 2000, and it increased to 868 in 2017. It is therefore recommended that urban planners and disaster managers should be fully trained in area of Geo-spatial management and SSDS in order to produce accurate multi-hazard maps as a pathway to Disaster Risk Reduction (DRR) in the state and the country at large.