Sampling in Geographical Fieldwork Using GIS Techniques , pp. 2 of 6

The ‘high erosion site’ was identified for having the most significant coastal retreat compared to the rest of the coastline. In addition, the ‘high erosion site’ had the narrowest stretch of beach, which highlighted that coastal erosion had taken place at that area (Figures 3a, 3b and 3c). The ‘high erosion sites’ were located along Cha-am south beach.

Utilising Remote Sensing-GIS Satellite Imagery

To further confirm the suitability of the two locations as data collection sites, Remote Sensing and Geographic Information System (GIS) technologies were employed. Remote sensing involves the sensing of a place or object remotely, to acquire information about the place or object (Ramachandran, n.d.). Remote sensing technique often uses satellites to help to collect and record information of the specific place with the help of electromagnetic radiation reflected off the Earth’s surface. This information is then processed into an image after being transmitted to a receiving station (USGS, n.d.). Such images could help to track the changes in a specific place over time. Remote sensing images can be used to track changes over a targeted area for various reasons, for example, glacial retreat and deforestation in the forest.

Remote sensing technology can be used hand-in-hand with GIS. GIS is a smart mapping technology that stores and maps geographical elements to reveal patterns. GIS is particularly useful to the study of spatial relationships. When data is entered and stored into the GIS system, the system is able to generate GIS maps depending on which data layers are included. GIS maps are useful to analyse information about numbers and density, and even which areas are more prone to flooding than others (National Geographic Society, n.d.). The investigation made use of GIS remote sensing techniques to extract data for coastal erosion along Cha-am’s coastline. This helped to determine the extent of coastal inundation and monitored the beach erosion along Cha -am’s coast.

Landsat satellites were used in this study to generate high-resolution satellite images of the coastline of Cha-am. Landsat satellites have polar orbits; hence they are able to capture information for most parts of the Earth along with the Earth’s rotation. Landsat satellites were first developed in 1972, and the first Landsat satellite was named, Landsat 1. Subsequently, Landsat 2, Landsat 3 and Landsat 4 were launched in 1975, 1978 and 1982 respectively. Landsat 5 was launched in 1984 and deactivated in 2013. It is said to be the “longest-operating Earth observation satellite”, producing high quality data for many years. Landsat 6 failed to orbit when launched in 1993. Landsat 7 and Landsat 8, launched in 1999 and 2013 respectively, are currently still in operation to provide daily global data.

An Inspiring Quote

"[Open-mindedness] includes an active desire to listen to more sides than one; to give heed to facts from whatever source they come; to give full attention to alternative possibilities; to recognize the possibility of error even in the beliefs that are dearest to us."

~ John Dewey, How We Think

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