Determining Long-Term Land Cover Dynamics in the South Baltic Coastal Zone from Historical Aerial Photographs

Andrzej Giza,Tomasz Komorowski,Paweł Czapliński,Paweł Terefenko

doi:10.3390/rs13061068

Abstract

Coastal regions are dynamic environments that have been the main settlement destinations for human society development for centuries. Development by humans and environmental changes have resulted in intensive land cover transformation. However, detailed spatiotemporal analyses of such changes in the Polish Baltic coastal zone have not been given sufficient attention. The aim of the presented work is to fill this gap and, moreover, present a method for assessing indicators of changes in a coastal dune environment that could be an alternative for widely used morphological line indicators. To fulfill the main aim, spatial and temporal variations in the dune areas of the Pomeranian Bay coast (South Baltic Sea) were quantified using remote sensing data from the years 1938–2017, supervised classification, and a geographic information system post-classification change detection technique. Finally, a novel quantitative approach for coastal areas containing both sea and land surface sections was developed. The analysis revealed that for accumulative areas, a decrease in the land area occupied by water was typical, along with an increase in the surface area not covered by vegetation and a growth in the surface area occupied by vegetation. Furthermore, stabilized shores were subject to significant changes in tree cover area mainly at the expense of grass-covered terrains and simultaneous slight changes in the surface area occupied by water and the areas free of vegetation. The statistical analysis revealed six groups of characteristic shore evolutionary trends, of which three exhibited an erosive nature of changes. The methodology developed herein helps discover new possibilities for defining coastal zone dynamics and can be used as an alternative solution to methods only resorting to cross sections and line indicators. These results constitute an important step toward developing a predictive model of coastal land cover changes.

Highlights

Coastal zones are highly dynamic regions that exhibit unique atmospheric, hydrospheric, lithospheric, and biospheric characteristics
The methodology proposed, that accounts for long-term land cover changes as a record of coastal dynamics, is a novel research approach that has never been applied to studies of the Polish Baltic Sea coastal zone
1938, 1951, 1973, 1996, and 2017 were processed to conduct a detailed long-term analysis of land cover changes in sections of the dune coast stretching over a total of 51 km

Summary

Introduction

Coastal zones are highly dynamic regions that exhibit unique atmospheric, hydrospheric, lithospheric, and biospheric characteristics. Numerous studies have indicated that weather conditions and rising sea levels are the primary factors influencing coastal erosion [1]. Since the mid-twentieth century, increased cyclonal activity has been observed in winter periods in the North Atlantic due to global climate change [2,3]. The number of extreme storm surges in the Baltic Sea is increasing steadily [4,5], which along with milder winters and limited ice cover, further exacerbates coastal erosion [6]. The observed rates of change in coastlines, in case of erosion, have been a significant concern for communities inhabiting littoral zones. The study of long-term changes in land cover is important, since it supplements the knowledge of Remote Sens.

Methods

Results

Discussion

Conclusion