The Effect of Human Activities Towards Coastal Dynamics and Sustainable Coastal Management

One of the disasters that often occur in coastal areas is abrasion. Abrasion causes coastal dynamics, including the East Coast of Rembang, Kragan Village, Kragan District, Rembang Regency. From 1975 to 1990, at least 50 meters of land from this area has been lost due to abrasion. This dynamic may become one of the causes of unsustainable management of the coastal environment and its natural resources. Various efforts have been made to overcome abrasion, but abrasion continues to hit this area, even until 2020. Qualitative and quantitative approaches were carried out in this study to discover the coast dynamics and various human activities that may trigger abrasion. Image interpretation, observation, interviews, and questionnaires were used as data collection techniques at three observation points in the Kragan Village area. This study concludes that the beach in Kragan Village has experienced dynamics with a total land loss of 46 meters from 2003 to 2020. Harmful activities carried out by humans resulted in abrasion so that the coast experienced dynamics. Human activities also affect coastal management, namely the basic principles of integrated coastal management and processes in the management of coastal areas.

Coastal dynamics of the Gulf of Kalamita (Western Crimea)

The performed research showed that since the first third of the 20th century until today the beach width at various sections of the Gulf of Kalamita has decreased two-to fourfold, and at some of them beaches have totally disappeared. The average coast erosion rate for the last 100 years has been 1.3 m/yr, with the maximum being 7.8 m/yr. These processes are accompanied with depletion of debris on the beach and underwater slope, erosion of bench deposits, and destruction of coastal structures. This is due to deficiency of beach-forming material resulted from intense economic management in the coastal area. Implementation of scientifically and technically sound coastal protection projects is essential to preserve the beaches of the Gulf of Kalamita.

Cartographie De La Dynamique Historique Du Trait De Côte Des Plages De Guédiawaye Et Malika (Dakar, Sénégal)

L’érosion côtière est une des causes de la disparition des plages, du recul des falaises et de la perte de terrains à valeur socio-économique et écologique. La compréhension de la dynamique côtière est donc primordiale avant d’entreprendre toute politique d’aménagement du littoral. Cette étude se propose de retracer la dynamique historique du trait de côte de la zone de Malibu à Malika au Nord de Dakar qui subit actuellement une forte pression humaine avec l’extension de la Voie de Dégagement Nord. Elle est basée sur l’analyse de données de télédétection au moyen du logiciel ArcGIS 10.4 et de l’extension DSAS 4.3 (Digital Shoreline Analysis System). Les résultats obtenus laissent apparaitre, entre 1942 et 2011, une évolution du trait de côte en faveur d’une érosion avec une vitesse moyenne de -0,15 m/an. Cette évolution, qui n’est pas uniforme d’un secteur à un autre mais aussi d’une période à une autre, serait essentiellement due à l’action des agents hydrodynamiques qui gouvernent les mouvements sédimentaires. Néanmoins, la pression humaine commence à se faire sentir avec l’extension de la Voie de Dégagement Nord, les extractions de sables et la coupe des filaos au profit des constructions humaines dont les conséquences sur la dynamique côtière peuvent être alarmantes. Coastal erosion is one of the causes of the disappearance of beaches, retreat of cliffs and loss of land with socio-economic and ecological value. Understanding coastal dynamics is therefore essential before undertaking any coastal development policy. This study aims to retrace the historical dynamics of the coastline from the Malibu to Malika area located in the north of Dakar which is currently under strong human pressure with the extension of the Northern Clearance Way. It is based on the analysis of remote sensing data using ArcGis 10.4 and the DSAS 4.3 extension (Digital Shoreline Analysis System). The results obtained show, between 1942 and 2011, an evolution of the coastline in favor of erosion with an average speed of -0.15 m/year. This evolution, which is not uniform from a sector to another, but also from one period to another, is essentially due to the hydrodynamic agents which govern sediment movements. However, human pressure is starting to be felt with the extension of the Northern Clearance Way, sand extraction and the cutting of casuarinas for human constructions benefit. The consequences of such practices on coastal dynamics can be alarming.