## 1 Introduction  
The natural and strategic characteristics, from an economic development perspective, make coastal areas places with high potential for the development of human activities [1, 2, 3]. They represent areas with significant natural interest, hosting unique ecosystems with high and rich biodiversity [2, 4]. Additionally, the characteristics of their landscapes, represented by the interaction of abiotic elements (beaches, dunes, cliffs, and marshes) and biotic elements (flora and fauna), enhance the need for conservation and a sustainable use of the coastal environment together with the economic use of ecosystem services [5, 6]. Historically, and increasingly over the past few decades, coastal areas have housed large population centres of high socioeconomic importance. The location and logistic, industrial, and productive opportunities (agriculture and fishing), along with the increase in tourism, concentrate nearly 11% of the world's population in coastal areas (around896 million people), according to 2020 data [7]. This upward trend in terms of population and economic activity development, which in many cases requires the development of infrastructure (buildings, factories, and communication routes), generates negative impacts related to the degradation of coastal ecosystems [8; 9]. The current global dynamics show an increase in the likelihood of extreme weather events [2; 5]. Coastal areas are therefore particularly sensitive to natural hazards such as storms, rising sea levels, or mass movements, all of which are becoming more severe [2; 5; 10]. This increase in coastal vulnerability to growing hazards related to global change results in a deterioration of the environment's adaptive capacity [11; 12; 13]. Consequently, it exacerbates the economic impacts on agricultural (food security), energy, tourism, and urban activities, as well as on people or the natural environment [11; 12; 13; 14; 15]. Recognizing the external processes responsible for triggering natural hazards becomes a practice of special necessity and importance to reduce or mitigate the impact of these events, whether fully or partially [16; 17; 18]. The southeast margin of the Ria de Arosa represents an environment of high ecological importance, characterized by protected natural spaces (PNS) of the Umia-Grove Intertidal Complex, the Ons-Grove Complex, a set of geological interest sites (geosites), and extensive areas of high landscape quality [19; 20]. Natural hazards, particularly coastal flooding, mass movements (e.g., landslides and rockfalls), or soil loss, are particularly relevant issues in this area due to its geographic configuration and the high population density recorded. In line with this fact, the degradation of its ecosystems, particularly wetlands, can directly affect the regenerative capacity of the coast and its resilience against extreme natural events or anthropogenic activities [11; 12; 13]. Consequently, it may jeopardize not only biodiversity but also the ecosystem services important to the local population. The rapid advancement of digital tools in recent decades, especially Geographic Information Systems (GIS), has made these technologies essential for land-use planning and decision-making processes. GIS enables the rapid and cost-effective management of large volumes of geospatial information, allowing for its organization, visualization, querying, integration, and analysis [21]. This ability to model and visualize scenarios for territorial planning enhances the transparency and reproducibility of the resulting outputs [22]. Multi-Criteria Decision Analysis (MCDA) is a decision-support tool applicable to various contexts and particularly useful in spatial planning [23]. It provides a systematic approach for integrating multiple spatial data layers, each representing different suitability criteria, to produce a composite map indicating the degree of suitability of each evaluated parcel [23].