How Well Can the Surface Water and Ocean Topography (SWOT) Satellite Mission Observe Irrigation Canals?

Abstract The capability of the Surface Water and Ocean Topography (SWOT) satellite for observing irrigation canals has remained relatively unexplored. Here, we assess SWOT observability of irrigation canal networks across 22 Asian countries using a new confidence level (CL) metric. Validation against in situ gauge observations showed that higher CL corresponds to significantly lower water‐level retrieval error. Of approximately 795,110 km of canals analyzed, 37.5% (297,799 km) show high confidence, 46.9% (373,035 km) moderate confidence, and 15.6% (124,276 km) low confidence of observability. Observability is highest in the Indus Basin, Indo‐Gangetic Plain, Bangladesh delta, North China Plain, and parts of Myanmar, the Philippines, Nepal, and the Mekong delta, and lowest across parts of Central Asia. Our analysis indicates SWOT can meaningfully support irrigation canal water monitoring across much of Asia's most intensively irrigated regions and around the world.