Manwan: reservoir area vs downstream gauge
Raw, uncalibrated radar · SWOT agreement r = 0.29
Water area is a signal, not storage volume. Gauge level also depends on rain and tributaries, so the two lines are context, not cause and effect. Gauge: Chiang Saen monthly mean water level (MRC PMFM public dashboard). Data: Mekong River Commission (MRC). Radar: our processing of Copernicus Sentinel-1.