AQUALAND analyzes the contribution of upstream aquatic and terrestrial systems to aquatic habitats. It is a grid-based watershed model. The software has two main components, the Watershed Delineator Tool and the Threats Assessment Tool. The watershed delineator identifies a watershed for each input aquatic core. The tool can delineate a circular buffer around each core, the entire watershed, a constrained watershed determined by following a flow grid upstream from a starting point and using a resistant surface classified by stream order and landuse or a user-defined watershed.