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Abstract. Floods are devastating natural disasters with a significant impact on human life and the surrounding environment. This paper analyses historical and recent flood (2012 extreme) peak flow at strategic locations, land use activities and Floodplain Vulnerability Index analyses of the Niger-Benue River Floodplain. The 2012 peak flow at Jederbode on the Niger River was about 50 % above the long term average. At Jebba (Niger), the 2012 peak flow of 1567 m 3 s −1 was also far higher than the long term mean annual peak flow of 1159 m 3 s −1 . The 2012 peak flow at Lokoja was also about 50 % above the historical average. The Benue River at Makurdi had peak flow of 16 387 m 3 s −1 which was also unusually higher than the historical average while Wuroboki (Benue) had peak flow of 3362 m 3 s −1 which was also much higher that the historical average (694 m 3 s −1 ). The mixed land use which supported diverse ecosystem services has the largest cover of 5654 km 2 (36.85 %) of the Niger-Benue floodplain. The flood vulnerability of the various land uses within the floodplain include; medium, high and very high levels. A four levels hierarchical implementation adaptation strategy for sustainable agricultural practices along the rivers flood plain was proposed. The implementation hierarchy includes: Community Concern, Local Authority Concern, State Concern and National Concern.

Introduction:Human activities exert great pressures on the environment which in turn cause environmental stresses of various intensities depending on the factors involved and the sensitivity of the receiving environment.Objective:This study examines the effects of anthropogenic activities along the sub-urban lagoon fragile coastal ecosystem using DPSIR framework.Results:The results show that the study area has undergone a tremendous change between 1964 and 2015 with the built up area increasing to about 1,080 ha (17.87%) in 2015 from 224 ha (1.32%) in 1964 at an average growth rate of 16.78ha per annum. The nature of the degradation includes an increasing fragility of the ecosystem through the emergence and expansion of wetlands, flooding and erosion as well as a reduction in the benefits from the ecosystem services. Population growth, between 2006 and 2015 for Ikorodu LGA, estimated at 8.84% per annum serves as the most important driving force in reducing the quality of the environment. This is in addition to Pressures emanating from anthropogenic activities. The state of the environment shows continuous resource exploitation (fishing and sand mining) with the impacts of the pressures coming from water pollution, bank erosion, biodiversity loss and flooding. Although there has been a strong policy formulation response from the government, weak implementation is a major challenge.Recommendation:The study recommends public awareness campaigns and the implementation of existing policies to ensure a sustainable sub-urban lagoon coastal environment..

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