Living shorelines are a form of Nature-based Solutions, which incorporate natural elements that provide flood and erosion risk management benefits. Climate change impacts are increasingly motivating communities in Canada to consider incorporating living shorelines in coastal protection schemes. Few studies have quantified wave attenuation by real saltmarsh vegetation in large-scale laboratory facilities, particularly for species native to the east coast of Canada. There is a knowledge gap on how seasonality affects wave attenuation by saltmarsh vegetation and how attenuation varies from the lower marsh to the higher marsh depending on species-specific plant traits. To bridge this gap, experiments were performed in a 5-m wide, 5-m deep and 120-m long wave flume facility. Preliminary results show that different saltmarsh species resulted in different degrees of wave attenuation. The experiments are still ongoing with the final test series expected to be run in spring/summer 2024.

Coastal development can have consequences for owners of riparian land. In fact, different Court' judgments have brought to light contentious landowner cases involving various territories bordering a waterway. On the shores of the St. Lawrence Estuary, the delimitation of the water domain attempts to respect French law. However, according to recent research, the current method seems inconsistent with its principles. Indeed, delimitation in Quebec is based on tide gauge data and morpho-sedimentary and botanical criteria are used in France to determine the position of the shoreline jet. Thus, this research project proposed a novel method to delineate the coastal boundary on the Saint-Lawrence Estuary based on morphometric analysis of the coastal area modelled by photogrammetric data acquired with low-cost UAV. The aimed precision is approximately 5 cm in planimetry and 10 cm in altimetry. A collection of different datasets was acquired in the St. Lawrence Upper Estuary in the summer of 2023, using a methodology adapted to the coastal environment. Preliminary tests of delimitation have considered the Geomorpon algorithm to classify the DTM. Delineate properties boundaries based on high-water mark and coastline boundary consists of an intricate task, since it necessarily need to ally different morphometric analysis with legal analysis. A challenging factor to delineate properties on the Saint-Lawrence Estuary area is that the law and regulations are highly variable, depending on the type of each coast. It results in a dynamic delimitation process of property involving ongoing refinement and adjustment, reflecting the complexity of the scientific investigation. The approach proposed by this research is a major contribution to land surveyors community and related geosciences scientific works related to coastal area.

In a context of climate change and of a concentration of human establishment and buildings on the coast, the risks of coastal erosion and flooding are constantly increasing, exacerbating the vulnerability of coastal communities, notably on the Quebec and French coasts. In addition, the difficulties of integrated coastal zone management and the multiplicity of stakeholder positions (citizen, elected officials, public administrations, local and regional organisations, and other stakeholders) complicate the managements of those risks. Progress in climate change adaptation, planning and implementation, have been observed in recent decades, but the challenges are still numerous, particularly in coastal areas. Rethinking those spaces at the interface between land and sea in a sustainable future is a challenge to which interdisciplinary research involving scientists, coastal risk management professionals, elected officials and residents in a partner-based approach, can contribute some essential insights. The Franco-Quebec research project ARICO, bringing together some 50 researchers from different disciplines and professionals from coastal territories, aims to gain a better understanding of the vulnerability of coastal areas exposed to the risks of erosion and flooding, in order to promote their adaptation by co-constructing with stakeholders adaptation scenarios. Several methods were tested, and different tools implemented: vulnerability indices, data dissemination platforms, comparative analysis of public policies, systemic timelines, population surveys, open forum, serious games, participatory workshops... A process of adaptation to coastal risks has been initiated with stakeholders in the two test areas. The methodology is distinct, but, in both cases, the research team is accompanying and supporting a territorial project initiated by local authorities, in which a reflection on adaptation scenarios is underway. Finally, this international research project, carried out in close collaboration with various local and national stakeholders, has helped to strengthen the adaptive capacities of the areas studied, through (1) a better assessment of their vulnerability to coastal erosion and flooding risks (population and infrastructure exposed, level of adaptation, resilience of coastal communities), (2) in-depth exchanges on the advantages and disadvantages of existing and planned public policies in both countries, (3) awareness-raising and decision-making tools, and (4) co-construction of adaptation scenarios.

The St. Lawrence system is critical for the economy, communities, cultural identity, and natural and ecological heritage of the province of Quebec, in Canada. This system is however experiencing increased pressures from the consequences of climate change and the increase in human activities on it and along its coasts. Six non-profit regional organizations, the ZIP Committees, oversee the monitoring and management of the estuarine and the Gulf portions of the St. Lawrence system, with the objectives to protect, conserve, manage, sustainably develop, and restore its coasts. To achieve this, they need ways to collect relevant geospatial data, develop intelligent tools, and effectively communicate information so that they and other stakeholders can articulate their interventions around informed decisions. Here we worked with these six committees to conduct an inventory of their collective capacities and needs regarding geospatial data collection, data processing, data analysis, data interpretation, data management, and data sharing. This allowed us to identify where the capacity of one committee met the needs of another one. In the coming months, we will centralize, complete, update, and review each existing procedure with the partners to ensure that the entire community of practice has access to standardized protocols based on the best knowledge available and a combination of everyone’s expertise, thus facilitating future data integration. A prioritization exercise was also performed to identify the main issues to address in a 5-year horizon. The top priority identified is the need for tools to detect, measure, and understand coastal ecosystem changes over time. An issue associated with this priority is that of spatial scale: stakeholders often do not know how to prioritize the specific locations within their territory where data collection is needed. Other priorities that were identified as less critical include the quantification of the value of ecosystem services as well as the detection of invasive species and wastewater discharges. Enabling stakeholders to use geomatics-based technologies and methods will allow them to optimize their resources dedicated to obtaining reliable and up-to-date information on their territory of intervention. This information will then be used to inform decision-making in contexts such as conservation or restoration.

Industrial port zones host several anthropogenic activities which are susceptible to cause cumulative impacts on coastal ecosystems. Consequently, a comprehensive environmental monitoring of these ecosystems can greatly help with the sustainable management of these areas. Here, we present a five steps preventive environmental management model called Enviro-Actions (Figure 1). The first three steps of the model create an observatory of the port area, beginning with the review of existing data and the identification of possible stress factors (Stage 1). Stakeholders and local actors in the port area are then met, allowing to establish management priorities (Stage 2), and an up-to-date portrait of the environmental quality of the area is produced along with recommendations for subsequent monitoring (Stage 3). Based on this portrait, near-real time monitoring and managing tools are implanted (Stage 4), to ultimately send Enviro-Alerts to take action and prevent environmental quality degradation in the industrial port zone (Stage 5). This model allows to monitor changes in several parameters of ecosystem quality, by sampling ecosystem data with multiparametric autonomous tools (water quality, air quality, underwater noise). Live transmission to an online environment supports Enviro-Alerts emission at different levels of management in the event of anomalies in regards to reference conditions of the ecosystem. The Enviro-Actions model allows to prevent environmental impacts on habitats and communities in industrial port zones, providing stakeholders complementary tools for sustainable development. By using multidisciplinary scientific expertise, neutral interpretation of results and transparent communications, it also increases social acceptability. This model is currently being implemented in Sept-Îles and Saguenay (QC, Canada), with the goal of being exported to other port areas in Canada.

Mangroves, vital ecosystems hosting rich flora and fauna diversity, provide crucial ecosystem services for local communities. However, their survival faces substantial threats due to climate change (rising sea levels, increasingly intense hydro-meteorological events, and droughts) and anthropogenic interventions lacking conservation awareness (road embankments fragmenting marshes, land-use change). This research focuses on the central region of the Yucatan state coast, Mexico, where mangrove distribution is intrinsically linked to the complex hydrology (surface and subsurface), hydrodynamics, and topo-bathymetry of the environment. The main objective is to identify potential mangrove species distribution scenarios based on water availability and salinity variability, considering fluctuations in freshwater (precipitation to freshwater springs) and saltwater inputs (through two estuarine mouths). This is achieved through the analysis of available hydrological databases and studies to characterize the area and create future scenarios, in-situ measurements of spatially and temporally distributed physicochemical variables, and numerical modeling of flow and transport (freshwater and saltwater, wind, tides). Through an interdisciplinary approach, this study also addresses the health of the mangrove ecosystem and its direct impact on the sustainable development of local communities. In this context, specific strategies for mangrove preservation and restoration are proposed, emphasizing the creation of channels and dredging existing water passages [1]. These actions play a crucial role in facilitating the recovery of physicochemical and ecological processes in mangrove water. It is demonstrated that, even under stressful conditions, vulnerability of mangroves can be reduced through the design and implementation of actions such as: (a) ensuring the quantity and continuity of flow through sediment management measures to improve hydraulic efficiency of estuarine mouths and freshwater springs, (b) creating strategic channels to reduce water residence times in marshes and wetlands, thereby favoring the aerobic-anaerobic condition of these ecosystems [2] ,[3]. With the technical-experimental support encompassed by this study, we aim to underscore the importance of interdisciplinary assessment for decision-making in the field of civil works integrated into the environment as part of the urbanization process. This is crucial in areas where local communities depend on sustainable utilization of the ecosystem services offered by marshes and mangroves [4]. Effective mangrove management not only translates to the preservation of the natural environment but also supports sustainable and resilient livelihoods in the context of ongoing global change. References : [1] Teutli-Hernández, C., & Herrera-Silveira, J. A. (2018). The success of hydrological rehabilitation in mangrove wetlands using box culverts across coastal roads in northern yucatán (SE, México). In Coastal Research Library (Vol. 25, pp. 607–619). Springer. https://doi.org/10.1007/978-3-319-73016-5_28 [2] Pacheco-Castro, R., Salles, P., Canul-Macario, C., & Paladio-Hernández, A. (2021). On the understanding of the hydrodynamics and the causes of saltwater intrusion on lagoon tidal springs. Water (Switzerland), 13(23). https://doi.org/10.3390/w13233431 [3] Yoshikai, M., Nakamura, T., Blanco, A., Hernández, B., Herrera, E., Ferrera, C., Almarza, F., Dimalanta, W., Basina, R., Albano, G., Rollon, R., Suwa, R., Ray, R., Primavera-Tirol, Y., Lourdes, M., Diego-Mcglone, S., & Nadaoka, K. (2023). Modeling flow and sediment dynamics in an estuarine mangrove forest and adjacent areas: the impact of mangrove forest dynamics on landscape evolution. EGU General Assembly 2023. https://doi.org/10.5194/egusphere-egu23-13835 [4] Herrera-Silveira, J. A., Lara-Domínguez, A. L., Day, J. W., Yáñez-Arancibia, A., Ojeda, S. M., Hernández, C. T., & Kemp, G. P. (2019). Ecosystem Functioning and Sustainable Management in Coastal Systems With High Freshwater Input in the Southern Gulf of Mexico and Yucatan Peninsula. In Coasts and Estuaries: The Future (pp. 377–397). Elsevier. https://doi.org/10.1016/B978-0-12-814003-1.00022-8