Review and analysis of the state of the art of studies and management plans carried out in different coastal areas within the framework of coastal risk assessment

• Autores: Haspert, Federico; Bindelli, Lucas; Tomazin, Nicolás J.; García, Pablo E.
• Año de publicación: 2018
• Idioma: español castellano
• Tipo de recurso: informe técnico
• Materia: Cambio climático; Protección costera; Modelación matemática; Erosión
• Institución: Instituto Nacional del Agua

Fil: Haspert, Federico. Ministerio de Obras Públicas. Secretaría de Infraestructura y Política Hídrica. Instituto Nacional del Agua. Subgerencia Laboratorio de Hidráulica; Argentina.
Fil: Bindelli, Lucas G. Ministerio de Obras Públicas. Secretaría de Infraestructura y Política Hídrica. Instituto Nacional del Agua. Subgerencia Laboratorio de Hidráulica; Argentina.
Fil: García, Pablo E. Ministerio de Obras Públicas. Secretaría de Infraestructura y Política Hídrica. Instituto Nacional del Agua. Subgerencia Laboratorio de Hidráulica; Argentina.
Fil: Tomazin, Nicolás J. Ministerio de Obras Públicas. Secretaría de Infraestructura y Política Hídrica. Instituto Nacional del Agua. Subgerencia Laboratorio de Hidráulica; Argentina.
The hazards (from the climate system) and the exposure and vulnerability (from the socioeconomic system) are the elements to take into account to advance on a coastal risk analysis. In the framework of Climate Change, it is necessary to focus on the study of the main threats of the system that for this case consist in waves and sea level. Waves are the main agent for the transport of sediment on beaches and are largely responsible for the shape of the beach, while the average level of the sea results in the basic condition on which the storm events and wave weather develop. In a first approximation to these variables through data and global models, the projections of the same were analyzed. The global atmosphere and ocean models (GCMs) used by the international scientific community to assess the effects of global climate change do not model the waves, the astronomical tide nor the meteorological tide (due to the different scales of these processes), so the latter should be studied separately based on the results obtained with the GCMs. On a global scale, the projections for an increase in the mean sea level for 2081-2100 are in the order of 30 to 60 cm in the less pessimistic scenario and 50 to 100 cm in the most pessimistic scenario (in the Mar del Plata area the increase range is expected to be somewhat higher). Regarding the tides, in the case of the astronomical one, historical changes have been observed in the phase and amplitude of some of the main components, but whose impact on the extreme sea levels is not sufficiently understood yet. In the case of the meteorological one, changes that are not yet specified at the regional level are expected. The situation with the projections of change in the swell is similar to the one described for the meteorological tide, but it could be affirmed that in the maritime coast of the province of Buenos Aires a slight increase in the average significant wave height could be expected, as well as a counter-clockwise rotation of waves in the southern section and a negligible one in the northern section, and a decrease and increase in the average period in the southern and northern sections, respectively. A review was made of the different methodologies and/or tools that currently contribute to the risk analysis of coastal zones. In this review, the studies that were prioritized were the most recent ones, but also those that had different types of approaches and methodologies. Among the collected methodologies the ones that stand out are those that serve as support for decision making for the assessment of the impact of coastal climate change based on Geographic Information Systems (GIS) and allow the use of free access global data to be able to carry out preliminary analyzes quickly and at low cost; models with a high degree of detail in the representation of risk indicators, analyzis prepared from quantitative hazard and vulnerability indexes made up of different indicators, and improvements to existing tools that allow for the opinion of experts to be taken into account when the data involved are inconsistent or insufficient. Numerical modeling has become an essential tool to quantify risks associated with different threats within coastal management, as well as to analyze the impact of infrastructure works and different future scenarios (especially associated with Climate Change). Depending on the physical problem they represent, these models can be hydrodynamic, sedimentological and/or morphological. They can be used independently or coupled together. The importance of remote sensing applied to the analysis of marine and coastal phenomena that affect littoral dynamics was also highlighted, analyzing those methodologies that explore the Earth's crust from the atmosphere, using satellites or airborne sensors (aerial photography, LiDAR, satellite images, radar) as well as other techniques, that also apply indirect measurement, such as the analysis of video and photographs, or those used in terrestrial and marine geophysics (georadar). Finally, different Coastal Management Plans (CMP) were revised, directing the search towards recent management tools and having different types of approach and methodologies: plans with a strong involvement of social actors, with lists of actions to be carried out in the short, medium and long term to reduce coastal risk, based on the principle of environments (or management units), with articulation of lines of action and management instruments under the analysis of impact indicators to assess efficiency. It is emphasized that most of the plans analyzed have an action horizon of between 5 and 10 years, enabling their review in the future."
Protocolo 1538 / Comitente: UNIDO - CTCN