Assessment Of Shoreline Morphological Changes In Brass (Niger-Delta, Nigeria)

ABSTRACT Assessment of shoreline morphological changes provides information about the historical, present and future shoreline positions. Such information is essential to coastal planning and managing natural coastal environments and human communities. Oil exporting facilities which are vital to the economy of Nigeria are located on the Okpoama- Brass shoreline in the Niger delta. The shoreline experiences morphological changes caused by natural and anthropogenic factors. Recent studies on shoreline morphological change in some parts of the Niger delta indicate that shoreline erosion is dominant over accretion. However, they did not provide information for the entire coastline of the Niger Delta. Approximately 551 transects were cast along the entire shoreline at 50m interval and rates of change statistics were calculated using the End Point Rate, Linear Regression, and Weighted Linear Regression methods. The estimate of shoreline position error for the extracted shorelines was 1m. The study reveals that in the long term, accretion is the dominant trend with overall mean shoreline change rate of + 0.1 m/yr ± 1m (meso accretion). However in the short term, the study revealed that erosion was dominant with overall mean shoreline change rate of - 0.42 m/yr ± 1m (meso erosion). Some transects revealed erosion rate as high as 7.03 m/yr ± 1m (extreme erosion). The study also forecasted the future shoreline position in fifty (50) years, which reveals erosion and minimal accretion. This study will serve as a guide in the planning and management of the natural environment and communities in the study area. The methodology used for this study can also be replicated in other selected areas along the coastline of the Niger Delta in Nigeria