{
  "context": {
    "id": "land-access",
    "title": "Land, people and access",
    "checked": "2026-10-14",
    "status": "Public working analysis authorized 15 October 2026; evidence and model limits remain",
    "population_year": 2022,
    "population_basis": "WorldPop / ZamStats v2.0; preliminary 2022 census counts disaggregated to a population grid",
    "confidence": "High for source documentation and reproducible arithmetic; mapped estimates and route completeness remain uncertain.",
    "kill": "Revised census inputs, missing or misclassified routes, boundary differences or finer-resolution distance analysis would change the shares.",
    "competing": "Settlement and infrastructure can develop together. Their proximity alone does not show who moved, why they moved, who owns land, or whether investment caused local pressure.",
    "limits": [
      "This is a settlement and transport map, not a land ownership register.",
      "A low population estimate does not mean land is empty, unclaimed, suitable or available.",
      "Straight-line distance is not travel time, a station catchment or proof of service access.",
      "Mapped rail is not proof of an operating train service. Proposed, abandoned and disused lines are excluded by tag; source classification can still be incomplete.",
      "A single population snapshot cannot establish migration, displacement or a causal effect of investment.",
      "Population and transport have different dates. This is a cross-date proximity comparison, not a historical reconstruction."
    ],
    "distances_km": [
      10,
      25,
      50,
      100
    ],
    "default_km": 50,
    "networks": {
      "rail": "Mapped rail",
      "combined": "Rail + main roads"
    },
    "road_filter": "OpenStreetMap highway=trunk or primary; not all roads and not an official corridor classification",
    "rail_filter": "OpenStreetMap railway=rail, excluding service=yard/siding/spur; no construction/proposed/disused/abandoned geometry",
    "sources": [
      {
        "id": "population",
        "title": "WorldPop and ZamStats: 2022 gridded population, v2.0",
        "date": "2022 population; release 4 June 2024",
        "url": "https://data.worldpop.org/repo/wopr/ZMB/population/v2.0/",
        "documentation": "https://data.worldpop.org/repo/wopr/ZMB/population/v2.0/ZMB_population_2022_v2_0_README.pdf",
        "license": "CC BY 4.0",
        "license_url": "https://creativecommons.org/licenses/by/4.0/"
      },
      {
        "id": "transport",
        "title": "OpenStreetMap contributors: rail, trunk/primary roads and places",
        "date": "Snapshot timestamp recorded in the downloaded extract",
        "url": "https://www.openstreetmap.org/",
        "documentation": "https://download.geofabrik.de/africa/zambia.html",
        "license": "ODbL 1.0",
        "license_url": "https://opendatacommons.org/licenses/odbl/1-0/"
      },
      {
        "id": "boundary",
        "title": "Natural Earth: 1:10m country outlines",
        "date": "Downloaded 14 October 2026; input hash recorded",
        "url": "https://www.naturalearthdata.com/",
        "documentation": "https://www.naturalearthdata.com/about/terms-of-use/",
        "license": "Public domain",
        "license_url": "https://www.naturalearthdata.com/about/terms-of-use/"
      }
    ]
  },
  "inputs": [
    {
      "file": "population.tif",
      "url": "https://data.worldpop.org/repo/wopr/ZMB/population/v2.0/ZMB_population_2022_v2_0_gridded_total.tif",
      "bytes": 20705987,
      "sha256": "3c478ee19638f06f119f961af07cb3ebc07c2b7536d9c39c3574bbf8a69db52d"
    },
    {
      "file": "mastergrid.tif",
      "url": "https://data.worldpop.org/repo/wopr/ZMB/population/v2.0/ZMB_population_2022_v2_0_mastergrid.tif",
      "bytes": 11650832,
      "sha256": "80aa91d8cb5b426b6edb40735cd811bd88725b029fad5c27fd85c8160a83b996"
    },
    {
      "file": "population-readme.pdf",
      "url": "https://data.worldpop.org/repo/wopr/ZMB/population/v2.0/ZMB_population_2022_v2_0_README.pdf",
      "bytes": 202760,
      "sha256": "846342d31adcf0d5e79281ecd0f70d63595a3a75cef23a74c045152472286198"
    },
    {
      "file": "countries.geojson",
      "url": "https://raw.githubusercontent.com/nvkelso/natural-earth-vector/master/geojson/ne_10m_admin_0_countries.geojson",
      "bytes": 13287234,
      "sha256": "239eec57ac17f100a11e2536cffc56752c318b50ae765b0918ff7aab4ce8f255"
    },
    {
      "file": "zambia-261013.osm.pbf",
      "url": "https://download.geofabrik.de/africa/zambia-261013.osm.pbf",
      "bytes": 252080622,
      "sha256": "fe9574cf96cd62e2ecad8887997e8284ca7fbd5c61005466df3276929aac32ab"
    },
    {
      "file": "transport.json",
      "url": "derived from the pinned Geofabrik extract by extract_land_transport.py",
      "bytes": 3174521,
      "sha256": "3daa4cc7a861c10e7074bec5f133c2c1f39259bce536c0e37856a7f20fcf7049"
    }
  ],
  "method": {
    "projection": "+proj=laea +lat_0=-13.5 +lon_0=27.5 +datum=WGS84 +units=m +no_defs",
    "aggregation_factor": 10,
    "display_cell_km": 2,
    "distance_basis": "Projected straight-line buffers; population and area assigned by approximately 1 km cell centres. Area uses valid mastergrid coverage, including inland water.",
    "population_display_retained_pct": 100.0,
    "boundary": "Natural Earth outline for display; WorldPop mastergrid coverage for the statistical area denominator.",
    "route_simplification_m": 100
  },
  "statistics": {
    "rail": [
      {
        "km": 10,
        "population": 6988476,
        "area_km2": 39761.9,
        "population_pct": 35.64,
        "area_pct": 5.3
      },
      {
        "km": 25,
        "population": 8614671,
        "area_km2": 93954.5,
        "population_pct": 43.93,
        "area_pct": 12.51
      },
      {
        "km": 50,
        "population": 10705262,
        "area_km2": 175428.1,
        "population_pct": 54.59,
        "area_pct": 23.36
      },
      {
        "km": 100,
        "population": 13085821,
        "area_km2": 323950.0,
        "population_pct": 66.73,
        "area_pct": 43.15
      }
    ],
    "combined": [
      {
        "km": 10,
        "population": 11349705,
        "area_km2": 132886.4,
        "population_pct": 57.87,
        "area_pct": 17.7
      },
      {
        "km": 25,
        "population": 14363620,
        "area_km2": 291390.8,
        "population_pct": 73.24,
        "area_pct": 38.81
      },
      {
        "km": 50,
        "population": 16866537,
        "area_km2": 490706.9,
        "population_pct": 86.01,
        "area_pct": 65.35
      },
      {
        "km": 100,
        "population": 18890444,
        "area_km2": 708447.6,
        "population_pct": 96.33,
        "area_pct": 94.35
      }
    ]
  },
  "totals": {
    "population": 19610769,
    "area_km2": 750838.4
  }
}