Geovariables

Geovariables (in some cases abbreviated to geovars) are variables which are derived from geospatial datasets. In most cases, this type of information is not available in surveys themselves. For example, we can generate the geovariable Average 12-month total rainfall (mm) for a location defined by a latitude and longitude.

Geovariables Metadata

In order to make sure that users easily understand geovaribles, the following attributes/metadta are defined for each geovariable.

• Theme This provides a broad category where this variable falls. For example, soil, rainfall, land cover etc

• Variable description Provides the definition of the variable in a non-mathematic fashion.

• Variable ID This is the variable name as used in the published or any dataset.

• Variable definition An exact description including formulas if necessary of how the variable is computed

• Variable type Whether the variable is a continuos or categorical

• Variable units Units of measurement for the variable

• Resolution This may refer more to the resolution of the data source

• Reference period If needed, time period associated with the variable. For example, for the variable 12-month total rainfall (mm) in July-June, starting July 2011 the reference period would be 2022-2012

• Dataset source Data (dataset name and URL) used to generate this variable.

Geovariables Master List

The tables below provide summary information (not all metadata) for the master list of variables. This is being called a master list because not all of these geovariables will be available and/or computed for each survey.

Distance and accessibility

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Distance	Household distance to nearest main road	dist01	Km	N/A	OpenStreetMaps, local sources	Yes
2	Distance	Household distance to nearest town of > 20,000 pop	dist02	Km	N/A	City population, local sources	Yes
3	Distance	Household distance to nearest major market (FEWSNET key market centers)	dist03	Km	N/A	FewsNET, USAID	Yes
4	Distance	Household distance to nearest border post on main road	dist04	Km	N/A	Tracks4Africa,roads, borders	Yes
5	Distance	Household distance to the headquarters of the district of residence	dist05	Km	N/A	World Gazeteer Towns, Statoids	Yes
6	Accessibility	Household travel time to nearest main road	trav01	Minutes	N/A	Global Friction Surface 2019	No
7	Accessibility	Household travel time to nearest town of > 20,000 pop	trav02	Minutes	N/A	Global Friction Surface 2019	Yes
8	Accessibility	Household travel time to nearest major market (FEWSNET key market centers)	trav03	Minutes	N/A	Global Friction Surface 2019	Yes
9	Accessibility	Household travel time to nearest border post on main road	trav04	Minutes	N/A	Global Friction Surface 2019	Yes
10	Distance	Household travel time to the headquarters of the district of residence	trav05	Km	N/A	World Gazeteer Towns, Statoids	Yes

Climatology

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Climatology	Average annual temperature calculated from monthly climatology, multiplied by 10 (°C)	clim01	Degrees Celcius	0.008333 dd	World Clim	Yes
2	Climatology	Average temperature of the wettest quarter, from monthly climatology, multiplied by 10. (°C)	clim02	Degrees Celcius	0.008333 dd	World Clim	Yes
3	Climatology	Total annual precipitation	clim03	mm	0.008333 dd	World Clim	Yes
4	Climatology	Precipitation of wettest month	clim04	mm	0.008333 dd	World Clim	Yes
5	Climatology	Precipitation of wettest quarter	clim05	mm	0.008333 dd	World Clim	Yes

Land typology

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Landscape Typology	Majority landcover class within approximately 1km buffer	land01	N/A	0.002778 dd	GlobCover v2.3	Yes
2	Landscape Typology	Percent under agriculture within approx 1 km buffer	land02	N/A	0.002778 dd	GlobCover v2.3	Yes
3	Landscape Typology	Agricultural ecological zones	land03	N/A	0.008333 dd	IFIPRI	Yes
4	Climatology	Population density range (people per km2)	land04	mm	0.008333 dd	WorldPop	Yes

Soil and terrain

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Soil and Terrain	Average elevation (m) within 1 km block	soil01	m	0.008333 dd	SRTM-90m	Yes
2	Soil and Terrain	Slope derived from 90m SRTM	soil02	Percent	0.008333 dd	SRTM-90m	Yes
3	Soil and Terrain	Topographic wetness index1	soil03	N/A	0.008333 dd	SRTM-90m	Yes
4	Soil and Terrain	Terrain Roughness2	soil04	N/A	0.008333 dd	SRTM-90m	Yes
5	Soil and Terrain	Nutrient availability	soil05	N/A	0.008333 dd	Harmonized World Soil Database	Yes
6	Soil and Terrain	Nutrient retention capacity	soil06	N/A	0.008333 dd	Harmonized World Soil Database	Yes
7	Soil and Terrain	Rooting conditions	soil07	N/A	0.008333 dd	Harmonized World Soil Database	Yes
8	Soil and Terrain	Oxygen availability to roots	soil08	N/A	0.008333 dd	Harmonized World Soil Database	Yes
9	Soil and Terrain	Excess salts	soil09	N/A	0.008333 dd	Harmonized World Soil Database	Yes
10	Soil and Terrain	Toxicity	soil08	N/A	0.008333 dd	Harmonized World Soil Database	Yes
11	Soil and Terrain	Workability (constraining field management)	soil08	N/A	0.008333 dd	Harmonized World Soil Database	Yes

Crop season parameters

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Crop Season Parameters	Average 12-month total rainfall3	crops01	mm	0.1 dd	NOAA-CPC Rainfall Estimates	Yes
2	Crop Season Parameters	Average total rainfall in wettest quarter within 12-month periods4	crops02	mm	0.1dd	NOAA-CPC Rainfall Estimates	Yes
3	Crop Season Parameters	Average start of wettest quarter in dekads.5	crops03	dekads	0.1 dd	NOAA-CPC Rainfall Estimates	Yes
4	Crop Season Parameters	12-month total rainfall6	crops04	mm	0.1 dd	NOAA-CPC Rainfall Estimates	Yes
5	Crop Season Parameters	Total rainfall in wettest quarter within 12- month period7	soil05	mm	0.1 dd	NOAA-CPC Rainfall Estimates	Yes
6	Crop Season Parameters	Start of wettest quarter in dekads8	crops06	dekads	0.008333 dd	NOAA-CPC Rainfall Estimates	Yes
7	Crop Season Parameters	Average total change in greenness within primary growing season9	crops07	N/A	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
8	Crop Season Parameters	Average timing of onset of greenness increase10	crops07	Day of the year	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
9	Crop Season Parameters	Average timing of onset of greenness decrease11	crops07	Day of the year	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
10	Crop Season Parameters	Total change in greenness within primary growing season 12	crops07	N/A	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
11	Crop Season Parameters	Onset of greenness increase 13	crops07	Day of the year	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
12	Crop Season Parameters	Onset of greenness decrease 14	crops07	Day of the year	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
13	Crop Season Parameters	Average EVI value at peak of greenness within growing season15	crops07	N/A	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes
14	Crop Season Parameters	EVI value at peak of greenness within growing seaso16	crops07	N/A	0.004176 dd	MODIS-MOD12Q2(DOY185) Land Cover Dynamics	Yes

Farming Plot

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Plot	Plot distance to househol17	plot01	Km	N/A	Survey GPS data	Yes
2	Plot	Plot slope	plot02	percent	N/A	SRTM-90m	Yes
3	Plot	Plot elevation	plot03	m	N/A	SRTM-90m	Yes
4	Plot	Plot Potential wetness index	plot04	N/A	N/A	AfSIS	Yes

Infrastracture

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Infrastracture	Distance to nearest Open CellID tower for 2G	d_2g	m	N/A	GSMA	No
2	Infrastracture	Distance to nearest Open CellID tower for 3G	d_3g	m	N/A	GSMA	No
3	Infrastracture	Distance to nearest Open CellID tower for 4G	d_4g	m	N/A	GSMA	No
4	Infrastracture	Percent of anonymizing region covered by strong 2G signal	good2g	percent	N/A	GSMA	No
5	Infrastracture	Percent of anonymizing region covered by weak 2G signal	poor2g	percent	N/A	GSMA	No
6	Infrastracture	Percent of anonymizing region with no 2G signal	none2g	percent	N/A	GSMA	No
7	Infrastracture	Percent of anonymizing region covered by strong 3G signal	good3g	percent	N/A	GSMA	No
8	Infrastracture	Percent of anonymizing region covered by weak 3G signal	poor3g	percent	N/A	GSMA	No
9	Infrastracture	Percent of anonymizing region with no 3G signal	none3g	percent	N/A	GSMA	No
10	Infrastracture	Nighttime light annual composite	hrea_rade9lnmu	Radiance	N/A	NOAA, Univeristy of Michigan
11	Infrastracture	Statistically estimated brightness levels	hrea_lightscore	Brightness	N/A	NOAA, Univeristy of Michigan	No
12	Infrastracture	Travel time (hours) to national capital	tt_natcap	Hours	N/A	various map sources, Weiss et al	No
13	Infrastracture	Travel time (hours) to nearest town greater than greater than 50,000	tt_popcenter	Hours	N/A	Thomas Brinkhoff: City Population, Weiss et al	No
14	Infrastracture	Travel time (hours) to nearest major city	tt_city	Hours	N/A	Thomas Brinkhoff: City Population, Weiss et al	No

Natural Hazards

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Natural Hazards	Number of years with drought affecting 30% or more cropland area in season 1	HDF_C_S1_LA30	Years	N/A	FAO	No
2	Natural Hazards	Number of years with drought affecting 50% or more cropland area in season 1	HDF_C_S1_LA50	Years	N/A	FAO	No
3	Natural Hazards	Number of years with drought affecting 30% or more cropland area in season 2	HDF_C_S2_LA30	Years	N/A	FAO	No
4	Natural Hazards	Number of years with drought affecting 50% or more cropland area in season 2	HDF_C_S2_LA50	percent	N/A	FAO	No
5	Natural Hazards	Depth of 1 in 5 year riverine flood	P_1in5	mm	N/A	FATHOM	No
6	Natural Hazards	Depth of 1 in 10 year riverine flood	P_1in10	mm	N/A	FATHOM	No
7	Natural Hazards	Depth of 1 in 50 year riverine flood	P_1in50	mm	N/A	FATHOM	No
8	Natural Hazards	Depth of 1 in 5 year rain-related flood	FU_1in5	mm	N/A	FATHOM	No
9	Natural Hazards	Depth of 1 in 10 year rain-related flood	FU_1in10	mm	N/A	FATHOM	No
10	Natural Hazards	Depth of 1 in 50 year rain-related flood	FU_1in50	mm	N/A	FATHOM	No

Conflict

ID	Theme	Variable Description	Variable ID	Units	Resolution	Data sources	Required
1	Conflict	Change in annual number of violent events occuring within 5km of location, between 2021 and 2017, where negative is net decrease	cnfdif_5km	Number	N/A	ACLED	No
2	Conflict	Sum of violent events occuring within 10km of location, during period 2017-2021	cnfsum_10km	Number	N/A	ACLED	No
3	Conflict	Change in annual number of violent events occuring within 10km of location, between 2021 and 2017, where negative is net decrease	cnfdif_10km	Number	N/A	ACLED	No
4	Conflict	Sum of violent events occuring within 20km of location, during period 2017-2021	cnfsum_20km	Number	N/A	ACLED	No
5	Conflict	Change in annual number of violent events occuring within 20km of location, between 2021 and 2017, where negative is net decrease	cnfdif_20km	Number	N/A	ACLED	No

Food Security

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1

Derived from modified 90m SRTM. Local upslope contributing area and slope are combined to determine the potential wetness index.

2

Derived from 90m SRTM using Meybeck relief classes and 5x5 pixel neighborhood

3

Months and/or year is specified based on the survey in question.

4

Months and/or year is specified based on the survey in question.

5

Dekads are in the range \(1-36\). The first dekad depens on the target year. For example, \(July, 2012 =1\). Multiple varibales possible for different years.

6

Months and/or year is specified based on the survey in question. Multiple variables are possible.

7

Months and/or year is specified based on the survey in question. Multiple variables are possible.

8

Dekads are in the range \(1-36\). The first dekad depens on the target year. For example, \(July, 2012 =1\). Multiple varibales possible for different years.

9

This an integral of daily EVI values averaged by admininstrative region (e.g., district)

10

Day of year is in the range \(1-356\) where \(July = 1\) will depend of the survey in question. Also, these values are averaged at administrative region (e.g., district)

11

Day of year is in the range \(1-356\) where \(July = 1\) will depend of the survey in question. Also, these values are averaged at administrative region (e.g., district)

12

This an integral of daily EVI values averaged by admininstrative region (e.g., district) and the growing season is specified by months and years based on survey. Multiple variables possible.

13

Day of year is in the range \(1-356\) where \(July = 1\) will depend of the survey in question. Also, these values are averaged at administrative region (e.g., district). Multiple variables possible.

14

Day of year is in the range \(1-356\) where \(July = 1\) will depend of the survey in question. Also, these values are averaged at administrative region (e.g., district). Multiple variables possible.

15

Growing season specified by month and year based on the survey and value averaged at admin region (e.g., district).

16

Growing season specified by month and year based on the survey and value averaged at admin region (e.g., district). Multiple variables possible.

17

Distances are calculated based on anonymized (modified) household GPS coordinates