Monitoring Spatial and Temporal Scales of Shoreline Changes in Lahou-Kpanda (Southern Ivory Coast) Using Landsat Data Series (TM, ETM+ and OLI)

Shoreline changes are crucial for assessing human-ecosystem interactions in coastal environments. They are a valuable tool for determining the environmental costs of socioeconomic growth along coasts. In this research, we present an assessment of shoreline changes along the eastern coast of Lahou-Kpanda of the Ivory Coast during the period from 1980 to 2020 by applying Digital Shoreline Analysis System method using Landsat Data Series. The measurement of the shoreline dynamics of the Lahou-Kpanda coastline is mainly described in three parts: the west straight cordon, the dynamics at the mouth and the east straight cordon. The findings show a drastic reduction in natural shorelines. The greatest transition occurred along the mouth segment of the coast, where the average erosive velocity approaches 90 meters each year and the average distance has decreased by around 2 kilometers. The Ivory Coast lost more than 40% of its biological shorelines between 1980 and 2020, according to this report, a worrying development because these are regions that were once biologically abundant and highly rich. In general, human operations on the Ivory Coast’s shorelines have never had such an impact. The effects of these changes on habitats, as well as the vulnerability of new shoreline investments to increased human activity and sea-level rise, must be measured.

Utilizing MIKE 21 Software to Create Simple Hydrodynamic Simulations

This paper aim to create simple hydrodynamic simulation by using MIKE 21. The module used in MIKE 21 is LITPACK. LITPACK is one of the modules in MIKE 21 to solve hydraulic and sedimentation problems in coastal areas. Especially in this paper, the LITTLITE engine in LITPACK will be used. LITLINE determines the coastline position using a timeseries of wave climatic data. The model is based on a one-line theory, in which the cross-shore profile is expected to remain unaltered during erosion/accretion, with minor adjustments. Coastal morphology is thus only defined by coastline location (cross-shore direction) and coastal profile at a given long-shore position. The simulation used in this paper is the influence of groins on shoreline dynamics. The results of the simulation show that some areas will experience abrasion and some will experience accretion.

Wave dynamics and shoreline evolution in deltas: A case study of sandy coasts in the Volta delta of Ghana

Erosion is a major challenge facing coastal regions globally and it is projected to increase on regional to global scale as sea levels continue to rise. Deltas, which are important ecosystems, are particularly vulnerable due to their low-lying nature, subsidence, reduction in sediment supply, population increase and exposure to increasing frequency of extreme events. The need for sustainable management of these systems requires accurate estimates of shoreline dynamics at the local scale and higher spatial resolutions for engineering and decision-making. In this paper, we assessed shoreline dynamics of the Volta River delta in Ghana for a medium-term of 12 years using high-resolution satellite imagery. The shoreline change rates are correlated with wave dynamics to explain the observed shoreline evolution within the delta. Our results confirms that erosion dominates the studied coasts with rates reaching as high as 31 m/year close to the mouth of the delta where water level shows a strong relationship with shoreline change. These rates are evidenced by the destruction of fishing villages such as Fuveme located close to the mouth. Anthropogenic factors, such as the construction of sea defence projects, are also influencing erosion patterns across the study area. We recommend a softer approach for coastal management within the delta.

Spatio-Temporal Analysis of Abrasion Susceptibility Effect on Land Cover in the Coastal Area of Bantul Regency, Yogyakarta, Indonesia

Shoreline dynamics naturally occur in coastal areas, and over time, are also influenced by anthropogenic processes taking place both on-site and upstream. Bordering the Indian Ocean, the coastal area of Bantul Regency in the Special Region of Yogyakarta is faced with typical strong and high waves that induce changes in its shoreline dynamics and activities. Consequently, tourism, a leading economic sector in the area, often needs to adjust to such changes. Here, shorelines were extracted from the spatial data of time-series Sentinel 2A imagery (2015, 2016, 2017, 2018, 2019, and 2020) using water index transformation, MNDWI, while the land cover changes were analyzed using the Decision Tree classification. Based on the results, accretion appeared most significant from 2016 to 2017, creating an additional 22.32 ha. In contrast, shoreline change from 2019 until 2020 indicated the most severe abrasion that led to a loss of 34.89 ha. The highest rate of landward shoreline change was 41.58 m/year.

STUDY OF THE RELIEF AND COASTLINE DYNAMICS OF LARGE COASTAL ACCUMULATIVE FORMS ACCORDING TO REMOTE SENSING DATA

The study of the relief of large coastal accumulative forms, based on modern technologies, is rele-vant for solving many applied problems. Coastal and underwater bars, shoals, banks are characteristic elements of large coastal accumulative forms’ geosystems. Previously existing methods of relief re-searches, especially underwater, were labor-intensive and expensive. Accordingly, the development and implementation of new methods of geographical research are necessary. The Dolgaya Spit, includ-ing its underwater shoal and the Elenin Bank, is one of the largest accumulative forms of the Sea of Azov. The purpose of our work was to obtain new information on the relief structure and the shoreline dynamics of the Dolgaya Spit based on the use of new research methods. Digital models of surface and underwater relief were built on the basis of processing Sentinel-2 satellite images and data from unmanned aerial photography. The subsequent analysis allowed identify regularities that reflect the current and previous hydro-lithodynamic conditions that determined the transformation of the Dolgaya Spit during its evolution. The fulfilled studies confirmed the possibility of successful use of modern remote methods for studying the relief of coastal accumulative forms.

Shrinkage of the tarns in the High Tatras (Slovakia, Poland)

This paper assesses the shrinkage of glacial lakes in the High Tatras by analysing the series of historical and actual orthophotomaps from 1949 to 2018. The shoreline dynamics during this period were established by detailed retrospective remote sensing, and the decrease in the former surface of the water was caused by intensive interaction between morphodynamic processes and the lake basins. Herein, we have identified 38 tarns with an assumed decline in the area. This assumption was based on a comparison of initial visual analysis of the historical aerial photographs and the current orthophotomaps which capture all High Tatras tarns. We selected ten tarns with the largest or most representative changes and performed detailed cartographic analysis on them. We also attempted this analysis over shorter periods whenever possible and herein we established from 2.5 to 32.2% decrease in lake water surface area during the monitored period. This decrease in shallow lake basins was accompanied by the presence of accumulated debris flows, fine fraction fluvial-proluvial deposits, and vegetation. The shallow glacial lake basins are sensitive indicators of irreversible changes in their catchment areas and this study, therefore, highlights the effectiveness of combining detailed orthophotomaps and historical aerial photos and GIS tools in researching glacial lakes shoreline dynamics in the alpine landscape. Retrospective shoreline analysis facilitates the assessment of the effects of morphodynamic processes on the development of tarns from the postglacial period until today.