Depending on the goal of the scenario, one might take different approaches to creating a scenario map.
Projections - based on historical trends can be used to describe the future. Future trends can be based on simple temporal dynamics, or a function of the land/marine use type and explanatory factors. This approach requires land-use land cover (LULC) data and explanatory factors from at least two different time points and assumes that future change follows the same dynamic of the past.
Visions - In some cases, it may be more useful to develop visions of the future that reflect the goals of stakeholders, communities, and organizations. In these cases, scenarios can be developed using information from stakeholders.
Optimizations - Planners may wish to explore scenarios that best meet goals within a specified constraint such as a budget. In these cases, scenarios are optimized landscapes or seascapes designed to meet particular goals.
Explorations of possible futures depict how events might unfold. These exploratory scenarios investigate possible—but unexpected—futures. They explore how factors beyond our direct influence might reshape the future.
The goals and approaches are not exclusive. A successful scenario map may cover multiple aspects: the growth of a LULC type may be projected based on past trends, estimates of land suitability may be based on empirical evidence or expert judgement, and the zoning plans may encompass the visions of stakeholders.
Qualitative storylines, quantitative estimates, and spatial representations are three common components of a scenario. Often, though not always, latter components are derived from the former ones. Iterations help ensure consistency among the components. Click on each component for detailed instruction on how to obtain the data and generate the results.
Since a growing amount of work has been conducted on scenario development, especially at a global scale and within the US, you may also use existing scenario as a reference or starting point when relevant.