Contemporary shoreline changes and consequences at a tropical coastal domain

Abstract

Coastal environment is affected by diverse human and natural activities, more than any other natural environment. The main aim of this study is to examine shoreline dynamics of the sandy beach of Mazatlán, a medium-sized tropical coastal city in north-west Mexico. This paper specifically investigates the shoreline change as impacted by natural and anthropogenic interferences on the Mazatlán coastline. The mean high water (MHW) shoreline positions were extracted from Landsat Images (2012–2016) and a 2016 GPS field survey data. Digital Shoreline Analysis System (DSAS) was then used to investigate the dynamics of the extracted shoreline movements and the relative changes. Results showed that 96% of the coastline is undergoing yearly small-scale erosion at two distinct rates. The first at −1.9 ± 0.9 m year−1 and the other at −1.4 ± 0.2 m year−1, which are noted at Cerritos and other sections of the coastline, respectively. Changes in the coastal behaviour, here, are attributed widely to suspected sea level rise; increasing tidal range in the region; and the lack of or inadequate accommodation space for sediment movement occasioned by landed assets alongshore. These factors are not only encouraging erosion but also causing the depreciation of landward assets.

Keywords

• Coastal processes
• morphodynamics
• human activities
• erosion
• DSAS
• Mazatlán
• coastal cities