Exploring the Ever-Changing Seashore Using Geoinformatics Technology

Ibra Lebbe Mohamed Zahir,Atham Lebbe Iyoob,Buddhika Madurapperuma,Kafoor Nijamir

doi:10.3390/earth2030032

Ibra Lebbe Mohamed Zahir, Atham Lebbe Iyoob + Show 2 more

Open Access

https://doi.org/10.3390/earth2030032

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Abstract

Detecting coastal morphodynamics is a crucial task for monitoring shoreline changes and coastal zone management. However, modern technology viz., Geoinformatics paves the way for long-term monitoring and observation with precise output. Therefore, this study aimed to produce explicit shoreline change maps and analyze the historical changes of the coastline at the east coast of the Ampara District in Sri Lanka. The histogram threshold method is used to extract data from satellite images. The time-series satellite images, acquired from 1987 to 2017, toposheet, and Google Earth historical images were compared having adjusted with the ground-truth to find the seashore changes in the study area. The histogram threshold method is used on band 5 (mid-infrared) for separating land from water pixels which means that the water pixel values were classified to one (1) and land pixel values to zero (0). The extracted shoreline vectors were associated with each other to determine the dynamics of changing shoreline of the study area. The Digital Shoreline Analysis System (DSAS) was used to find shoreline movements for each period of time. As a result, it was observed by the cross-section analysis within 100 m shoreline—seaward range along the study area—in which severe erosion has occurred northward of the Oluvil Harbor and anomalous accretion southward of the harbor because of the breakwaters constructed in the port entrance which hinder the long shore sediment transport along the study area. This situation has resulted in many ramifications to the coastal zone of the study area in socio-economic and environmental aspects in which the coastal protection mechanisms have not been well implemented to curb such issues.

Highlights

Ecosystem conservation and environmental management of coastal habitats are essential for safeguarding the security, good living conditions of the society, and the success of socio-economic ranges of the coastal fringe community
Urgent efforts are needed to conserve the coastal environment from the poor coastal zone management process, which ignores natural ecosystems that have seriously been impacted by climatic and/or anthropogenic actions
Remote Sensing data covering the coastal area of Ampara District were acquired from Landsat ETM+ (1987, 1997, 2007) and Landsat OLI/TIRS (2017) from the Earth Explorer web portal

Summary

Introduction

Ecosystem conservation and environmental management of coastal habitats are essential for safeguarding the security, good living conditions of the society, and the success of socio-economic ranges of the coastal fringe community. Urgent efforts are needed to conserve the coastal environment from the poor coastal zone management process, which ignores natural ecosystems that have seriously been impacted by climatic and/or anthropogenic actions. Coastal zone management helps minimize impacts arising from natural and manmade disasters, such as sea-level rise, tsunami, erosion and biodiversity loss [1]. Because of the dynamic nature of the shoreline, morphological features, such as dune crest and cliff, vegetation line, and hydrology, are useful to determine the shoreline position [3]. This context reveals that the coast and shoreline are most commonly employed for the purpose of shoreline change mapping

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