Incorporating the Use of Time Series Remote Sensing Data to Assess the Vulnerability of the Thai Coast to Climate Change Induced Coastal Hazards

บทคัดย่อ

The climate change has the direct and indirect effects on natural negative changing such as disasters, animal and forestry reduction and habitat loss. Coastal changes including accretion and erosion are also affected by climate change which tend to intensify. Samut Prakan and Chachoengsao are two of the coastal provinces in Thailand having high economic and population growth which lead to the increment of coastal land use and the destruction of coastal resources. In addition, the characteristics of muddy coasts in Samut Prakan and Chachoengsao are susceptible to sediment movements. These cause severe coastal erosion in Samut Prakan and Chachoengsao. This project aims to provide the data of coastal erosion/accretion in Samut Prakan and Chachoengsao, over 40 kilometres long, from 2017 to 2020. The rates of coastal changes would be generated and calculated by Digital Shoreline Analysis System (DSAS) v.5, the extension of ArcMap, based on the statistical concept of a linear regression. In addition, the image processing uses PlanetScope satellite imagery and the Normalised Difference Water Index (NDWI), spatial analysis function in ArcGIS, in water extraction process. The result shows that 40.33% of the study area are eroded while 59.67% are accreted. In addition, each part of study areas has different rates of shoreline changes depending on the diversity of coastal impacts and protections. Coastal protections including hard-engineered structures, soft protection structures and shoreline protection from nature, especially mangroves, as well as climate change are the main concerns of shoreline changes in this project analysis. The coastal protections play the vital role in preventing shoreline erosion from offshore factors, such as the intensify of winds, waves and marine disasters, and onshore factors, such as land subsidence and coastal land use. Furthermore, the result also infers that the order of coastal protection placement has the potential influences on preventing the shoreline from erosion as well as sedimentation increment of muddy coasts.