Community-based assessment of coastal erosion in Lagos, Nigeria

Coastal erosion is a natural process that constantly reconfigures beaches, either in a landward or seaward direction. This study aims to assess the situation, causes, and impacts of coastal erosion on selected communities in Lagos State, Nigeria. Three local government areas (LGAs) that share boundaries with the coast (Ibeju-Lekki, Eti-Osa and Badagry-West LGAs) were purposively sampled. Google Earth Pro images were acquired from Landsat, Copernicus, Maxar technologies, and TerraMetrics for 1984, 1999 and 2021 to analyze shoreline movement dynamics using Digital Shoreline Analysis Software. A structured questionnaire was used to elicit information on the communities' perceptions. We used the convenience sampling method to administer 670 samples of the questionnaire at a 95.52% response rate. Images analysis revealed that Eti-Osa has the highest erosion distance (98.54 m) at an erosion rate of 8.88 m/year, while Badagry-West LGA has the least erosion distance (25.82 m) at an erosion rate of -2.31 m/year. This confirms the respondents' perception of coastline erosion and accretion which varies significantly across communities at X-2 (18) = 378.54, p < 0.05. The perceived leading causes of coastal erosion include heavy rainfall, intense storms, sea-level rise, developmental activities, and the anger of the gods, and they vary significantly across the communities at communities (X-2 (36) = 135.46, p < 0.05). The malevolent effects of this phenomenon, which include loss of homes and properties, groundwater quality impairment, relocation of settlement, and a threat to tourism, also vary significantly across communities. These communities are characterized by a low level of resilience to coastal erosion, hence susceptible to impending effects of climate change.

Automated summary

This study aims to assess the situation, causes, and impacts of coastal erosion on selected communities in Lagos State, Nigeria. Through satellite image analysis and questionnaire surveys, it was found that there are significant differences in the extent and causes of coastal erosion in different regions, which have detrimental effects on the livelihoods and tourism industry of local communities. Moreover, these communities have a low resilience to coastal erosion, making them susceptible to the effects of climate change.