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Table 2 Image features used for level 1 and level 2 classifications

From: An exploratory GIS-based method to identify and characterise landscapes with an elevated epidemiological risk of Rhodesian human African trypanosomiasis

  Classes Features Image Notes
Level 1 classification Open water Object mean band 4 (near infrared): threshold of 5.5% April Light in band 4 absorbed by water
  Built up & bare ground; wet vegetation types; dry vegetation types Object mean band 3 (red) April Vegetation type discrimination
   Object mean band 2 (green) November Identification of healthy vegetation
   Object mean band 3 November Vegetation type discrimination
   Object mean band 5 (mid infrared) November Vegetation and soil moisture content
   Object mean band 7 (mid infrared) November Identification of built up areas and bare ground
   Object length/width   
   NDVI difference, January to November   Differentiation of vegetation types
Level 2 classification Woodland & dense savannah*; crops & open savannah* Object mean band 2 April Related to healthy vegetation, biomass, plant type or vegetation moisture content
   Object mean band 3 April  
   Object mean band 4 April  
   Object mean band 5 April  
   NDVI difference, January to April, January to November and April to November   Differentiation of vegetation types
  Seasonally flooding grassland**; lake fringe swamps** Object mean band 4 November Identification of vegetation and soil moisture content, biomass, plant vigour and water
   Object mean band 5 November  
  1. All classifications used a nearest neighbour algorithm with the exception of open water, which utilised a threshold [26, 27].
  2. *Obtained using sub-classifications of the “dry vegetation types” class.
  3. **Obtained using sub-classifications of the “wet vegetation types” class.