Integrating multidisciplinary instruments for assessing coastal vulnerability to erosion and sea level rise: lessons and challenges from the Adriatic Sea, Italy

Climate scenarios produce climate change-related information and data at a geographical scale generally not useful for coastal planners to study impacts locally. To provide a suitable characterization of climate-related hazards in the North Adriatic Sea coast, a model chain, with progressively higher resolution was developed and implemented. It includes Global and Regional Circulation Models representing atmospheric and oceanic dynamics for the global and sub-continental domains, and hydrodynamic/wave models useful to analyze physical impacts of sea-level rise and coastal erosion at a sub-national/local scale. The model chain, integrating multiple types of numerical models running at different spatial scales, provides information about spatial and temporal patterns of relevant hazard metrics (e.g., sea temperature, atmospheric pressure, wave height), usable to represent climate-induced events causing potential environmental or socio-economic damages. Furthermore, it allows the discussion of some methodological problems concerning the application of climate scenarios and their dynamical downscaling to the assessment of the impacts in coastal zones. Based on a balanced across all energy sources emission scenario, the multi-model chain applied in the North Adriatic Sea allowed to assess the change in frequency of exceedance of wave height and bottom stress critical thresholds for sediment motion in the future scenario (2070–2100) compared to the reference period 1960 to 1990. As discussed in the paper, such projections can be used to develop coastal erosion hazard scenarios, which can then be applied to risk assessment studies, providing valuable information to mainstream climate change adaptation in coastal zone management.

Section: Case Studymentioning

confidence: 99%

Assessment of Climate Change Impacts in the North Adriatic Coastal Area. Part I: A Multi-Model Chain for the Definition of Climate Change Hazard Scenarios

Torresan

Gallina

Gualdi

et al. 2019

“…Wave-current dynamics represent a feature of paramount importance in the northern Adriatic basin, both for triggering local circulation [13,60] influencing connections in terms of amount of dense water produced [59] and driving sediment re-suspension and mobilization [14,61,62]. Modifications induced by climate changes in wave-current dynamics need to be carefully evaluated, since they can be regarded as among the main threats to coastal protection and stability, with important implications for the assessment of littoral management plans and for mitigation efforts [4,63].…”

Section: Discussionmentioning

confidence: 99%

“…The development of efficient tools to accurately represent nearshore wave and current-induced dynamics is essential for today's operational and forecasting applications in coastal zones [3,4]. High-resolution wave and hydrodynamics modeling offer an extensive range of capabilities to support The modeled site includes, from North to South, the coastal area between the south-side of Porto Garibaldi and the Reno River mouth (Figure 1), and comprises the mouth of Logonovo channel (zone a) at Lido degli Estensi, where sediments transported northwards from the Reno outflow are intercepted by the jetty of Porto Garibaldi, the touristic shoreline of Lido di Spina (zone b), and the old outlet plain of Gobbino channel (zone c) with low-lying plains.…”

Section: Introductionmentioning

confidence: 99%

Coupled Wave-2D Hydrodynamics Modeling at the Reno River Mouth (Italy) under Climate Change Scenarios

Gaeta

Bonaldo

Samaras

et al. 2018

This work presents the results of the numerical study implemented for the natural area of Lido di Spina, a touristic site along the Italian coast of the North Adriatic Sea, close to the mouth of River Reno. High-resolution simulations of nearshore dynamics are carried out under climate change conditions estimated for the site. The adopted modeling chain is based on the implementation of multiple-nested, open-source numerical models. More specifically, the coupled wave-2D hydrodynamics runs, using the open-source TELEMAC suite, are forced at the offshore boundary by waves resulting from the wave model (SWAN) simulations for the Adriatic Sea, and sea levels computed following a joint probability analysis approach. The system simulates present-day scenarios, as well as conditions reflecting the high IPCC greenhouse concentration trajectory named RCP8.5 under predicted climate changes. Selection of sea storms directed from SE (Sirocco events) and E-NE (Bora events) is performed together with Gumbel analysis, in order to define ordinary and extreme sea conditions. The numerical results are here presented in terms of local parameters such as wave breaking position, alongshore currents intensity and direction and flooded area, aiming to provide insights on how climate changes may impact hydrodynamics at a site scale. Although the wave energy intensity predicted for Sirocco events is expected to increase only slightly, modifications of the wave dynamics, current patterns, and inland flooding induced by climate changes are expected to be significant for extreme conditions, especially during Sirocco winds, with an increase in the maximum alongshore currents and in the inundated area compared to past conditions. coastal planning and decision assessment, accounting for typical features at a coastal engineering scale, such as nonlinear processes of wave propagation and interactions between offshore and coastal structures and the inclusion of inshore boundary conditions, such as river run-off.In recent years, research efforts have focused on the development of methodological frameworks based on advanced numerical modeling [5,6], which can be used to study the effects of future climate change scenarios affecting both the intensity and frequency of storm-surge events, wave climate, currents, sea-level rise, and riverine sediment discharge. Since the above-mentioned phenomena may increase the flood risk for coastal areas, the understanding of their dynamics at coastal scale becomes essential for the design of climate-change resilience protection and, in general, spatial planning activities.Thus, the development of multipurpose measures mitigating erosion and inundation and increasing coastal defense efficiency requires a challenging prediction of sea forcings variation induced by the estimated effects of climate change.Recently, regional future scenarios accounting for the Intergovernmental Panel on Climate Change (IPCC) sea-level projections at 2100 characterized by Representative Concentration Pathways equal to +8.5 W/m 2 (here...

“…Using coupled model combined observational data from buoys to investigate their evolution is also an important research work in the future. Additionally, the impact of cyclones on the evolution of the coastal strip and sediment dynamics (e.g., [87]) are also worth studying.…”

Section: Future Workmentioning

confidence: 99%

Response of Coastal Water in the Taiwan Strait to Typhoon Nesat of 2017

Yang

Tian

et al. 2019

The oceanic response of the Taiwan Strait (TWS) to Typhoon Nesat (2017) was investigated using a fully coupled atmosphere-ocean-wave model (COAWST) verified by observations. Ocean currents in the TWS changed drastically in response to significant wind variation during the typhoon. The response of ocean currents was characterised by a flow pattern generally consistent with the Ekman boundary layer theory, with north-eastward volume transport being significantly modified by the storm. Model results also reveal that the western TWS experienced the maximum generated storm surge, whereas the east side experienced only moderate storm surge. Heat budget analysis indicated that surface heat flux, vertical diffusion, and total advection all contributed to changes in water temperature in the upper 30 m with advection primarily affecting lower depths during the storm. Momentum balance analysis shows that along-shore volume acceleration was largely determined by a combined effect of surface wind stress and bottom stress. Cross-shore directional terms of pressure gradient and Coriolis acceleration were dominant throughout the model run, indicating that the effect of the storm on geostrophic balance was small. This work provides a detailed analysis of TWS water response to typhoon passage across the strait, which will aid in regional disaster management.