Coastal cliff erosion: a bibliometric analysis and literature review

Cliffed (and rocky) coasts are geomorphic features occurring in about 80% of the coastline of the world and are strongly influenced by a broad range of both natural and anthropogenic processes that may cause serious erosion problems. Since the sea wave motion is a fundamental driver of cliff erosion, the cliffs become sensitive to increasing of global sea levels and to extreme weather events, which are both associated with global warming. Because of its importance, a considerable amount of investigations on coastal cliff erosion (CCE) were reported during the last decades. A bibliometric analysis is an useful tool to identify patterns of a given theme from a large body of academic literature. There is no previous evidence of a global bibliometric analysis in the literature in English on themes of CCE. Therefore, the aim of this article was to carry out a bibliometric analysis from Scopus database of CCE for the period 2000–2023. Once obtained, two filtering steps for selection of documents consisting of a custom R script implementation and a careful reading of the remaining documents were applied. During the search, a dynamic approach that puts emphasis on the processes operating on rocky coasts was selected instead of an evolutionary geological perspective. The final list reached 583 documents. A second aim was to discuss the research trends and challenges based on the latest highly-cited documents. As main result, the trend of the scientific production in the theme of CCE had an increasing interest over the last years, with an average compound annual growth rate of 15.6%. On the other side, the results demonstrated that even though the USA took the second place, European countries (United Kingdom, Italy, France, Portugal, Spain and Poland) lead the ranking; therefore, there is a scarcity of knowledge about the theme in large regions such as South America and Africa where seacliffs are dominants.