Climate driven sea-level rise is one of the most common reasons for coastal hazards. Evadzi et al. (2019) characterize the large-scale climate forcing that drives mean sea-level (MSL) variability on the West African coast and its offshore waters in the observation period (1993–2013). For this purpose, the authors performed statistically analyses on several available data sets: sea-level data from tide gauges, satellite altimetry, gridded sea-level reconstruction, meteorological reanalysis, high resolution ocean model simulation driven by this meteorological reanalysis, and observational oceanographic data sets. The authors combined different sea-level records, and constructed a regionally representative sea-level curve for Ghana (1929–1981).
In order to find appropriate remedies, Bitan and Zviely (2019) calculated the economic losses from public bathing beaches, due to the potential threat of sea-level rise (SLR) based on an economic analysis. The authors selected for the study three of the main Mediterranean public bathing beaches of Israel. To calculate the morphological impact of SLR, the authors used a modification of the Bruun Rule. By using a benefits-transfer approach, consumer surpluses from other areas were adjusted to the Israeli beaches. For future projection of sea-level rise the authors referred to the latest report of the Fifth Intergovernmental Panel on Climate Change (IPCC). Based on these data the value loss for each beach was calculated for SLR from 0.2 m to 1.0 m at 0.2 m intervals. It is likely that Dado beach (Haifa) will be severely damaged or even lost by 0.4 m SLR, while Tel Aviv Promenade and Ashdod beaches would be severely affected by 1.0 m SLR. The overall of the annual losses of public benefits is estimated to be NIS 122 million ($31 million) and NIS 416 million ($104 million) for values of 0.2 m and 1.0 m SLR respectively.
Bagdanavičiūtė et al. (2019) focus on the more complex effects of sea-level rise combined with meteorological events on sandy beaches. Their study aims to quantify coastal risks associated with erosion and inundation accelerated by sea-level rise and extreme storms events for the specific conditions of the eastern Baltic Sea coast as an example of a micro-tidal semi-enclosed seas. The authors make an attempt to develop a measure that characterises climate-related external hazards, the exposure (of people and assets at risk of being damaged) and vulnerability of human and natural systems. About 11% of the study area is under very high risk. The largest risk values occur close to tourist and industrial centers near Klaipėda, around the Palanga pier and north of Šventoji.
Completely event-related are deposits due to the effect of storms and tsunamis. Schneider et al. (2019) present new data of accurate determination of geometric parameters for a holistic understanding the formation of storm and tsunami deposits and for modelling wave magnitudes responsible for the displacement of large boulders along the coast of Oman. The reconstruction of boulder movements along coastlines is a new approach that can be generalized for a better understanding of storm and tsunami dynamics. An important technology to estimate the change of coastlines in order to study cause and effect relations in the marine coastal environment is provided by the analyses of remote sensing data.
Jia et al. (2019) analysed the coastlines of sand-barrier lagoons that are the locations of coastal economic development along the eastern coast of Hainan Island in southern China. Here, increased human activities have remarkably destabilized and damaged the coastal ecosystems. The authors used innovative technology to classify and evaluate six phases of overlapping coastlines in Li’an and Xincun Lagoons in Lingshui County in southeastern Hainan Island between 1987 and 2013. The method applied combines the analysis of remote sensing images with ocean dynamics and bathymetric surveys.
Comparable results have been achieved by Li et al. (2019) who have investigated morphological change in the Qinzhou Bay (QZB), southwest China, using bathymetric charts and remote sensing data. Summarizing the results, the bathymetry and coastline of QZB have changed dramatically in recent decades. Land reclamation caused a decrease of subaqueous area of about 8% over the last 50 years while the average growth rate of the coastline was 2.07 km/yr between 1978 and 2013. Hereby it has to be considered that the natural curvy shape of the coastlines is being replaced by straighter artificial coasts. During the period from 1960s to 1990s, the evolution of QZB was mainly governed by natural factors with slight deposition or erosion in the deep troughs. From 1990s to 2010s, intensive large-scale human activities, such as port building, channel dredging and artificial island construction became the main causes affecting morphological changes in the QZB. The authors claim that only sustainably integrated coastal zone management can maintain the balance between economic development and ecological health.
But it is not only the morphodynamic environment that has to be considered when investigating hazardeous effect of human activities in coastal areas. The geochemical environment has to be taken into consideration as well. Modern salt lakes belong to a growing class of natural systems undergoing compositional change due to increased human activity along their shores. To understand the full consequence of anthropogenic-driven changes, detailed geological and geochemical study of such salt lake systems is required. Kotov et al. (2019) have investigated changes recorded in the peloids (lake muds) in Crimean salt lake systems and compared them with the similar systems in the Dead Sea region. In addition to natural reasons for differences in the geochemical peloid facies, the impact of human activities influences the salt, granulometric and microelemental compositions of peloids. A complete lack of halite in the Lake Kuchuk-Adzhigol mud is most likely related to intensive anthropogenic desalination, as well as to the input of drainage and waste water. The coarsest muds were found in Lake Saky, which reflects changes in the hydrochemical regime of the lake. Ferrous sediments of the Cimmerian stage are widespread in the East of Crimea. Until recently, these deposits were exploited through open pit mining (e.g., the iron ore mine Kamish-Burun), which could amplify Fe-Ti-Cr-K-V-Pb-Y-Mn-As-Co associations in the Lake Tobechik muds.