Spatio-Temporal Analysis of Shoreline Movements along the Coast from Keta to Kedzi in the Volta Region-Ghana

Abstract

In response to the inadequacy of traditional mitigation methods along Ghana's eastern shoreline and other eroded coastal areas, this study investigates the spatio-temporal dynamics of shoreline movements along the coastal stretch from Keta to Kedzi, in the Volta Region of Ghana. The research spans the period from 1990 to 2020 and employs shoreline data derived from high-resolution aerial imagery, alongside Landsat 7 and 8 images. Utilizing Digital Shoreline Analysis System (DSAS) software 5.1 and ArcGIS/ArcMap 10.8.2, the analysis incorporates key metrics such as Shoreline Change Envelope (SCE), Net Shoreline Movement (NSM), and End Point Rate (EPR). The findings reveal a nuanced pattern, with approximately six out of eight kilometres experiencing moderate to high accretion, while the remaining stretch faced significant erosion. Specifically, Keta exhibited an average NSM of 99.98 metres and an EPR of 5.26 metres per year. Vodza recorded an average NSM of 130.21 metres and an EPR of 6.85 metres per year. Conversely, Kedzi displayed an average NSM of -73 metres and an EPR of -3.87 metres per year. This study underscores the necessity for periodic monitoring, recommending a five-year interval for researchers and relevant stakeholders, including the Ministry of Water Resources, Works, and Housing. Additionally, it emphasizes the imperative for targeted intervention, especially Kedzi due to the pronounced and pervasive nature of erosion in that area.