{
  "generated_utc": "2026-08-27T15:16:24Z",
  "aoi": [
    85.35,
    28.3,
    85.8,
    28.7
  ],
  "res_m": 30.0,
  "dems": {
    "cop-dem-glo-30": "Copernicus GLO-30, TanDEM-X 2011-2015",
    "nasadem": "NASADEM, SRTM 2000",
    "alos-dem": "ALOS World 3D-30m, 2006-2011"
  },
  "pairwise_difference_m": {
    "cop-dem-glo-30 - nasadem": {
      "all": {
        "median": -1.09,
        "std": 17.95,
        "p5": -29.4,
        "p95": 15.45
      },
      "flat": {
        "median": -0.72,
        "std": 7.53,
        "p5": -17.0,
        "p95": 3.36
      }
    },
    "cop-dem-glo-30 - alos-dem": {
      "all": {
        "median": -1.52,
        "std": 21.88,
        "p5": -27.28,
        "p95": 18.56
      },
      "flat": {
        "median": -1.2,
        "std": 5.85,
        "p5": -9.61,
        "p95": 0.9
      }
    },
    "nasadem - alos-dem": {
      "all": {
        "median": -0.48,
        "std": 16.73,
        "p5": -18.47,
        "p95": 22.39
      },
      "flat": {
        "median": -0.49,
        "std": 5.77,
        "p5": -4.76,
        "p95": 9.78
      }
    }
  },
  "seed": {
    "lat": 28.40022,
    "lon": 85.45009,
    "valley_floor_m": 3125.0
  },
  "impoundment_volume_by_dem": [
    {
      "rise_m": 10,
      "stage_m": 3135.0,
      "footprint_m2": 3974400,
      "volume_m3": {
        "cop-dem-glo-30": 429653920,
        "nasadem": 415063424,
        "alos-dem": 412320832
      },
      "spread_frac": 0.041
    },
    {
      "rise_m": 20,
      "stage_m": 3145.0,
      "footprint_m2": 4202100,
      "volume_m3": {
        "cop-dem-glo-30": 470492000,
        "nasadem": 455104064,
        "alos-dem": 452375744
      },
      "spread_frac": 0.039
    },
    {
      "rise_m": 30,
      "stage_m": 3155.0,
      "footprint_m2": 4435200,
      "volume_m3": {
        "cop-dem-glo-30": 513691328,
        "nasadem": 497480640,
        "alos-dem": 494639744
      },
      "spread_frac": 0.038
    },
    {
      "rise_m": 40,
      "stage_m": 3165.0,
      "footprint_m2": 4647600,
      "volume_m3": {
        "cop-dem-glo-30": 559140480,
        "nasadem": 542212352,
        "alos-dem": 539164416
      },
      "spread_frac": 0.037
    },
    {
      "rise_m": 60,
      "stage_m": 3185.0,
      "footprint_m2": 5081400,
      "volume_m3": {
        "cop-dem-glo-30": 656528320,
        "nasadem": 638206656,
        "alos-dem": 634754304
      },
      "spread_frac": 0.034
    }
  ],
  "note": "Same fill geometry through three DEMs of different epochs. The spread is a floor on volume uncertainty, not a full error budget: it excludes error in the radar-derived water outline and in the stage estimate, and the debris dam itself is in none of these DEMs."
}