Operative Heritage: A Methodological Framework for Post-Disaster Territorial Reconstruction—The Tajogaite Eruption in La Palma as a Case Study

Post-disaster territorial reconstruction processes reveal a persistent gap between the recognition of heritage as having a cultural, memorial, or landscape value and its effective integration into spatial decision-making. Drawing on the post-volcanic context created by the 2021 Tajogaite eruption on La Palma (Canary Islands, Spain), this paper introduces the concept of operative heritage as a methodological framework for transforming heritage values into active criteria for territorial reconstruction. The research develops a process-based methodology structured around the identification, characterization, and assessment of active heritage assets, their organization into operative heritage reconstruction units, and their subsequent translation into objectives, intervention strategies, implementation instruments, and monitoring mechanisms. Building on previous research on water systems, memory, vegetated landscapes, participatory processes, and territorial reconstruction, the study proposes a taxonomy organized into interconnected layers: ecological–perceptual heritage, hydrological–territorial heritage, memorial heritage, social heritage, and emerging geological heritage. The framework integrates cartographic tools, perceptual analysis, Geographic Information Systems, participatory approaches, and a Territorial Activation Index designed to assess the operational capacity of each reconstruction unit. The findings demonstrate that operative heritage moves beyond a purely cartographic or conservation-oriented approach and illustrate the operational potential of the proposed methodology through an exemplary application, providing a transferable framework to support planning, management, and design processes in territories affected by abrupt environmental transformations.