FLOOD PLAIN ENCROACHMENT AND LOKOJA FLOOD INCIDENCES

Abstract

Background: Lokoja city is a confluence to two major rivers in Africa, river Niger and Benue. Flooding occurred in the city whenever neighboring countries: Guinea, Niger, Mali, and Cameroon release excess water from their dams. This study examine flood plain encroachment and flood incidences in Lokoja. Method: Cross sectional survey was adopted for the study. Both qualitative and quantitative data were used for the study. Geographical Information System was used to acquire spatial data and imagery of residential buildings that were sited on the flood plain of river Niger and its tributaries. 730 housing units along river Niger flood plain were sampled using 0.02% of the sample frame. Chi-square was used to examine the significant difference in the compliance of building to Physical Planning standards on river setback. Results: The prevalence of non-adherence to 45 meter Physical Planning standards on rivers setbacks was 63.1% on river Niger flood plain and 79.7% to ganaja stream. Chi-square statistic is x²=10812, P<0.005. No statistical significant difference in the compliance of residential building to physical planning standards on rivers and streams setbacks. Conclusion: The study has demonstrated that central to Lokoja flooding are land use activities arising from urbanization, occupation of flood plain and metrological factors. Mitigation measures and initiatives were advanced in this paper to make the city more resilient to flood disaster.

Keywords: Floodplain encroachment, Lokoja flood incidence, Flood Risk mitigation.