Advanced Remote Sensing Methods for High-Resolution, Cost-Effective Monitoring of the Coastal Morphology Using Video Beach Monitoring System (VBMS), CoastSnap, and CoastSat Techniques

Abstract

The dynamic behaviour of the coastal environment demands for continuous monitoring to understand the impacts of various natural and anthropogenic activities on the coastal geomorphology. This will be achieved through the application of three recent remote sensing techniques together for coastal monitoring, namely, Video Beach Monitoring System (VBMS), CoastSnap, and CoastSat, are presented in this chapter with a pilot study along the Thiruvananthapuram coast in the southwest (SW) coast of India. The study aims to illustrate the application and capabilities of these techniques for understanding the coastal processes and the related changes in the morphology along the coast. Data from two VBMS stations (Valiyathura and Varkala), one CoastSnap station (Adimalathura), and six CoastSat locations (Adimalathura, Kovalam, Valiyathura, Shangumukham, Muthalapozhi, and Varkala) along Thiruvananthapuram coast, have been used. Details of installations of VBMS and CoastSnap stations and a discussion on the preliminary results with their interpretation are presented. Coastal morphological parameters like beach width, and surf zone width (at daily and hourly intervals) have been derived from the video imagery and CoastSnap photographs and validated with field measure ments (correlation <85%). The results are then used to study the short-term shoreline changes as it is ideal to understand the abrupt morphological changes due to the impact of cyclones and also to observe the time taken for recovery, particularly in critical/vulnerable areas which are not accessible for taking in situ measurements during such ephemeral events. In addition, CoastSat method has been used to study the historical shoreline changes in recent years (since 2015) from satellite imagery. To summarise, the results obtained from this pilot study are quite encouraging and show that the combination of the three techniques can be employed for successful monitoring of any critical/vulnerable location along the Indian coast. The long-term site-specific primary data once collected from these methods can be used for the development of a high-resolution database for the Indian coast, which can provide valuable information on the coastal processes and related changes, thereby, providing reliable and timely information to the coastal scientists/engineers for taking appropriate decisions for disaster mitigation as well as management and also planning of coastal development and protection related activities.