Validating models of one-way land change: an example case of forest insect disturbance
Context: Validation of models of Land Use and Cover Change often involves comparing maps of simulated and reference change. The interpretation of differences between simulated and reference change depends on the characteristics of the process being studied. Our paper focuses on validation of models of one-way land change processes that spread in space. Objectives: Our objective is to develop a method for validation of one-way land change models, such that the method provides objective information about the spatial distribution of errors. Methods: Using distance analysis on reference data, we build a baseline model for comparison with simulations. We then simultaneously compare the four maps of reference at initial time, reference at final time, simulation at final time, and baseline at final time. We also use Total Operating Characteristic curves and multiple-resolution map comparison. We illustrate the methods with a simulation of forest insect infestations. Results: The methods give insights concerning the reference data and the spatial distribution of misses, hits, and false alarms with respect to initial points of infestations. The new methods reveal that the simulations underestimated change near initial points of spread. Conclusions: The spatial distribution of errors is a topic of land change models that deserves attention. For models of one-way, geographically-spreading processes, we recommend that validation should distinguish between near and far allocation errors with respect to initial points of spread.
Harati, Saeed; Perez, Liliana; Molowny-Horas, Roberto; and Pontius, Robert Gilmore, "Validating models of one-way land change: an example case of forest insect disturbance" (2021). Geography. 712.