Augmented reality visualization of SWAT+ hydrological simulations via a GPS-based mobile application

Hydrological models like Soil and Water Assessment Tool Plus (SWAT+) are essential for watershed management, although their outputs are difficult for non-technical users to interpret. This study presents an Augmented Reality (AR) application integrating SWAT+ outputs for visualization. A data converter transforms SWAT+ outputs to cloud datasets. The AR system visualizes precomputed SWAT+ outputs using the nearest HRU or channel centroid, including soil water, water yield, percolation, evapotranspiration, precipitation, uncalibrated sediment and nutrient outputs, and streamflow, with spatial filtering to reduce clutter. In the Geumho River watershed (268 HRUs and 268 channels), soil water in agricultural and paddy-field HRUs ranged from 33–74 mm, while channel discharge varied from <1 to >2000 m3/s. SWAT+ showed satisfactory performance (NSE = 0.67/0.55; KGE = 0.82/0.77; R2 = 0.69/0.60), although predictive uncertainty remained limited during peak-flow conditions. The proposed framework supports interpretation of precomputed SWAT+ outputs rather than independent model validation.