Shoreline Change Analysis in Parts of the Barrier–Lagoon and Mud Sections of Nigeria Coast

Abstract

This study assesses the short- and long-term changing position of the shorelines along the barrier lagoon and mud section of the Nigeria coast using remote sensing techniques. Five shoreline positions, covering a 30-year period (1986–2016), were extracted from medium resolution multi-spectral Landsat satellite imageries using both manual and semi-automatic shoreline extraction methods. Approximately, 533 orthogonal transects were cast using DSAS at simple right angles along the entire coast at 250-m interval. The shoreline change analysis was calculated using the Net Shoreline Movement and the End Point Rate techniques. The results show that the shoreline is highly dynamic; with the average rate of erosion estimated to be 28.08[Formula: see text]m/year and the average rate of accretion estimated to be 20.56[Formula: see text]m/year. While the persistence of erosional tendencies was found mainly in the Okesiri-Abereke-Aiyetoro parts of the mud section of the shoreline, the accretional tendencies was found mainly in the Aboraji-Araromi (barrier lagoon) and the Ajegunle-Jinriwo-Awoye (mud section) parts of the shoreline. The high dynamism of the shoreline is mainly attributed to the increasing frequency of storm surges in the area with over 13 incidents experienced within this period. This study submits that addressing coastal erosion and flooding problems in Nigeria should be based on the system boundary model where the coastal process and dynamics are constantly monitored holistically rather than locally or regionally as it is currently being done. This will also ensure the incorporation of the extent, frequency and intensity of extreme event in the development of adaptation measures.

A Spatio-Temporal Analysis of Shoreline Changes in the Ilaje Coastal Area of Ondo State, Nigeria

“…This study confirms the prevalence of erosional processes in the western and central sections of the coast, with erosion being more pronounced in the central section. These findings align with the conclusions of previous studies by Badru et al [40] and Dada et al [39]. Popoola [43] also observed erosion dominating the central section of the coast in his research.…”

“…Popoola [43] also observed erosion dominating the central section of the coast in his research. Remarkably, Badru et al [40] emphasized the vulnerability of the Okesiri, Abereke, and Aiyetoro areas to persistent erosional tendencies, underscoring the significance of these communities due to their substantial size within the region. The widespread erosion along the Ilaje mud coast is influenced by a combination of geomorphic and anthropogenic factors.…”

“…Adediji and Ezenwa [38] compared satellite images from 1986 and 2013 with a topographic map from 1969, while Dada et al [39] examined coastline changes using satellite images from 1987 to 2017 in the Ilaje region. Additionally, Badru et al [40] and Komolafe et al [41] investigated coastal changes using statistical techniques such as end point rate (EPR) and Net Shoreline Movement (NSM) over different time periods. Daramola et al [42] conducted a study on changes in coastal positions employing the linear regression rate (LRR), endpoint rate (EPR), and root mean square error (RMSE) methods.…”

Coastal Vulnerability Assessment: A Case Study of the Nigerian Coastline

“…Based on the detailed geomorphological map of the Atlantic coastline (Figure 2) prepared using USGS Landsat imagery, the major landforms of the region include mud coast, lagoons, creeks, rivers, coastal plain, peninsular, sand beaches, flood plain, islands, tidal flats, estuaries and mangroves. The southwest coastline is classified basically into two zones based on geomorphology, beach type, ecology and the ecosystem services that the coastline offers [46]. It stretches for about 350 km and covers 6185 km 2 of land.…”

Morphological Changes along the shoreline of the arcuate Niger Delta from Parts of Delta State to Akwa Ibom State between 1986 and 2016

“…The coast has long been an area of great importance, providing communities with a multitude of benefits such as food, clean water, jobs, recreation/tourism, natural harbours for commerce, trade, and transportation, and is critical for sustained fisheries. The attractiveness of the coast has resulted in disproportionately rapid expansion of economic activities, settlements, urban centers, and tourist resorts (Oyegun et al, 2016;Badru et al, 2017).…”