Table 1 Variables considered for the model of proportion of 16-km² cells burned (using random forest). The final list of variables following variable selection is shown in Fig. 5. Variables which changed annually are italicized and static variables are not italicized. See Supplementary material for additional details on variables

Response

Proportion burned

Lizundia-Loiola et al. (2020)

Proportion of area burned within 16-km² cells

Political

Region

Famine Early Warning Systems Network (FEWS NET), https://fews.net/

Regional states of Ethiopia

Time

Year

Fire year was included to detect temporal trends

Climate

CHIRP precipitation

Funk et al. (2015)

Climate

FLDAS soil moisture

McNally et al. (2017)

0–10 cm depth

Climate

FLDAS temperature

McNally et al. (2017)

Mean monthly temperature at 2 m

Vegetation

Potential natural vegetation types

Friis et al. (2010); van Breugel et al. (2015)

Categorized into 14 vegetation types (Fig. 6 and Table S3)

Vegetation

Normalized Differenced Vegetation Index

MODIS vegetation indices (MOD13Q1v006)

Per-pixel maximum value from all 16-day vegetation indices layers in a given calendar year

Vegetation

Enhanced Vegetation Index

MODIS vegetation indices (MOD13Q1v006)

Per-pixel maximum value from all 16-day vegetation indices layers in a given calendar year

Land cover

Land cover types

Regional Centre for Mapping of Resources for Development, https://rcmrd.maps.arcgis.com/apps/webappviewer/index.html?id=c954194840d74c48a760485fe00ffb1e

From Landsat imagery, available annually 2000–2017

Human influence

Tropical Livestock Units per km²

Jahnke (1982); Gilbert et al. (2018)

Calculated from Gridded Livestock of the World v. 3, relative to 2010

Human influence

Livelihood zone type

FEWS NET Livelihood Zones, https://fews.net/

Categorized into agropastoral, pastoral, cropping (Meher dominant), cropping (Belg dominant), other/unknown

Human influence

Human population density

Lloyd et al. (2019)

Human influence

Protected area types

World Database on Protected Areas (https://www.protectedplanet.net/)

Categorized into: non-protected, UNESCO-MAB Biosphere Reserve, World Heritage Site, National Park, Sanctuary, Wildlife Reserve, National Forest Priority Area, Controlled Hunting Area

Human influence

Probability of tsetse fly occurrence

Leta et al. (2015)

Terrain

Elevation

Shuttle Radar Topography Mission (SRTM) v4

90 m pixels

Terrain

Slope

SRTM

Terrain

Terrain Ruggedness Index (TRI)

from SRTM, following Riley et al. (1999)

Terrain

Standard deviation of elevation

from SRTM

Using a 7×7 pixel window (630 m)

Soils

Soil nutrient availability

Wieder et al. (2014)

Nutrient availability (SQ1)