Social analysis network of environmental governance related to the management of the land-sea continuum in Reunion Island

Data collection took place in Réunion between January 2024 and December 2025 with the aim of conducting a social network analysis (SNA) of environmental governance related to the management of the land-sea continuum in Réunion. A total of 36 semi-structured interviews, each lasting approximately one hour, were recorded. Stakeholders were identified based on their role in the decision-making chain and their organizational level, which included at least one of the following criteria: (i) formal decision-making authority, (ii) regulatory or management responsibility, (iii) generation of knowledge or technical expertise related to the continuum, (iv) institutionalized representation of sectoral interests, or (v) participation in formal consultation or coordination forums.

The objective was to document the diversity of positions, roles, knowledge, and relationships among stakeholders to ensure a representative picture of the plurality of viewpoints.

The interview guides focused on:

          1. The roles and responsibilities of stakeholders;

          2. Their perceptions of land-sea interactions;

          3. The gaps between scientific knowledge generation and public policy implementation;

          4. Relationships among stakeholders in land-use planning and the management of the land-sea continuum;

          5. Prospects for development in Réunion by 2050.

Three networks were constructed using social network analysis (SNA) to describe the interactions between institutions and stakeholder groups involved in environmental governance related to the management of the land-sea continuum. Each sociological network analysis corresponds to a different period: 1946–1981, 1981–2007, and 2007–2025. This diachronic approach allows us to identify continuities and breaks in power relations and to assess the extent to which institutional transformations lead—or do not lead—to changes in governance.

Sociological network analyses (SNAs) were conducted using the collected data and an iterative process, during which respondents were contacted by email or phone to discuss the reliability of preliminary results. The first two periods employ qualitative coding of relationship types. Qualitative coding reflects the nature of the link and the type of relationship between subgroups. The classification of relationships is based on the following functions:

          1. Authority: decides, approves, authorizes, monitors, enforces

          2. Coordination: collaborates, serves on an advisory or scientific committee, forms partnerships

          3. Influence: lobbying, political pressure, obstruction, strategic negotiation

          4. Knowledge: scientific expertise, data provided, awareness-raising, information

          5. Conflict: opposition, mistrust, public disagreement, legal action

The final section is supplemented by quantitative coding. Quantitative coding also allows us to capture the links and tones between subgroups based on the interviews. Each mention of an actor adds +1 to the link coding. Tone is divided into three categories: (i) positive: ally, support, trust, (ii) neutral: factual, non-judgmental, (iii) negative: problem, mistrust. The average tone is calculated. To neutralize the effect of uneven sampling, occurrences of links between actors were weighted by the number of interviews conducted per subgroup.