Land Disturbance Alert Classification System (LDACS)

In contrast to other alert systems, DIST-ALERT continues to monitor pixels where it has identified an alert in the past. The DIST-ALERT retains the date of the most recent detection of disturbance, keeping users informed of the most up-to-date changes.

Several input datasets used to produce the LDACS contain temporal gaps or known mapping errors that may affect classification accuracy. Please refer to the technical note for more information on the limitations of the input datasets.

The classification system uses a static version of the SBTN natural lands map to identify potential conversion events. Updates to this map only occur when the source data set is revised, which may result in alerts being evaluated against outdated land use information. As a result, disturbances that alter the ecological state of the land (e.g., severe fire or tree cover loss) are not reflected in the natural lands mask used for classification, potentially contributing to inclusion or exclusion errors depending on the disturbance sequence and timing.

Because potential conversion is identified based on the duration of vegetation loss, there is an inherent delay in labeling these alerts. Although vegetation loss may be detected shortly after clearing, alerts are not assigned to the potential conversion class until they exceed the 75-day duration threshold. This delay allows for greater confidence in classification but may reduce the timeliness of conversion detection for rapid response.