Table 1 Description of AccessMod input data sets. Names of mandatory data sets are in bold

Raster

population distribution grid

Spatially-explicit distribution of population over the area. Point estimates coming from survey of administrative units should not be attributed to a single grid cell, but would need to be appropriately spread over the subunit surface of the administrative units

landuse grid

Spatial distribution of the different categories of land use on which travelling speed may be different. This grid can be combined in AccessMod with additional landscape elements (e.g. roads, rivers) to obtain the final landcover grid

digital elevation model (DEM)

Altitude distribution used to derive slopes and correct travelling speeds in the case of anisotropic movements

exclusion area grid

In a scaling-up analysis, it can define an area where no new health facility can be placed but where some population might nevertheless be living (e.g. swamps, military zone, disaster prone areas, etc)

Vector

health facilities locations

This point shapefile contains the geographic locations of the existing network of health facilities. Its attribute table contains the population coverage capacity and the facultative maximum travelling time for each health facility

road network

This line shapefile contains the road network. Different types of roads can be incorporated and combined with the landuse grid

barriers to movements

Both line and polygon shapefiles can be treated as complete barriers to movement and can be integrated in the final landcover grid

Tabular

travelling scenario

This file defines the travelling speed and the mode of transportation (e.g. walking, bicycling) of each landcover

new health facility information table

This file is used in the scaling-up analysis. It holds information on the different types of health facility and their associated population coverage capacity