Coastal vulnerability assessment: A case study of Samut Sakhon coastal zone

The Samut Sakhon coastal zone (~41.8 km), which was selected as a study area due to its low-lying topography, has been increasingly impacted by climate change and erosion processes affecting the local community. This study examined the vulnerability area in this region by combining a physical process vulnerability index (PVI) and a socio-economic vulnerability index (SVI). Four physical variables (coastal slope, coastal erosion rate, mean tidal range, and mean wave height) and four socio-economic variables (land use, population density, cultural heritage, and roads/railways) were employed. The result was a single vulnerability indicator of a coastal vulnerability index (CVI) showing that the high vulnerability area, covering an area of 1.3 km² (0.45% of total study area), was located in Ban Bo, Ka Long, Bangyaprak, Bangkrajao, Khok Kham, Na Kok, and Puntainorasing. The moderate vulnerability area covered an area of 28 km² (9.5% of total study area), the low vulnerability area 180 km² (60.56% of total study area), and the very low vulnerability area 88 km² (29.52% of total study area). The CVI map indicated that it was highly differentiated and influenced by socio-economic indicators, rather than physical indicators. However, comparison between the different results of the PVI and SVI can contribute to understanding the variability and constraints of vulnerability. The results of this investigation showed that the study area was more correlated with aspects related to socio-economic characteristics than physical parameters.