Detecting Coastline Change with All Available Landsat Data over 1986–2015: A Case Study for the State of Texas, USA

Nan Xu

doi:10.3390/atmos9030107

Abstract

Coastline change often results from social and natural factors, such as human activities in the coastal zone, long-term and short-term sea level change, hurricane occurrences, subsequent recovery, and so on. Tracking coastline change is essential to deepen our understanding of coastal responses to these factors. Such information is also required for land use planning and sustainable development of coastal zones. In this context, we aimed to collect all available Landsat data (TM: Thematic Mapper, ETM+: Enhanced Thematic Mapper Plus and OLI: Operational Land Imager) over 1986–2015 for tracking the coastline dynamic and estimating its change rate in the State of Texas, USA. First, the land vs. water maps at an annual scale were derived from the satellite images. The border between land and water represents the coastline in this study. Second, the annual land area was obtained to characterize the coastline dynamic and a linear regression model was used for estimating the change rate. We also analyzed the potential driving factors of the observed coastline change. The results reveal that the coastline in the State of Texas changed at a rate of −0.154 ± 0.063 km2/year from 1986 to 2015, which indicates that the coastline has mainly experienced an erosion over the past three decades. Specifically, 52.58% of the entire coastline retreated to the land while a 47.42% portion advanced to the ocean. Long-term sea level rise can result in the erosion of coastline. Hurricane occurrences can explain the relatively strong coastline erosion. Besides, significant difference between the coastline change rate with a higher curvature and a lower curvature was observed. This study establishes a general method for detecting coastline change at large spatial and long-term temporal scales, by using remote sensing that can give fundamental information on coastline change. This is important for making scientific and reasonable policies of sustainable development of coastal zones.

Highlights

Coastline retreat is a potential consequence of climate-change driven sea-level rise, as a result of permanent passive submersion and coastal erosion [1,2,3]
This study establishes a general method for detecting coastline change at large spatial and long-term temporal scales, by using remote sensing that can give fundamental information on coastline change
The change rates and the corresponding uncertainties were calculated along the coastline in the

Summary

Introduction

Coastline retreat is a potential consequence of climate-change driven sea-level rise, as a result of permanent passive submersion and coastal erosion [1,2,3]. Tracking the coastline change can be used to investigate the potential association between spatial-temporal patterns of sea-level rise and those of coastline changes, and make it possible to provide fundamental information for government officials and coastal managers to make scientific and rational policies for land use planning and sustainable development of coastal zones [9,10]. It is necessary to track the coastline dynamic at large spatial scales and over long time periods, especially for sandy coastlines as the world’s coastlines are dominated by sandy shores [11].

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