Senegal Population Map Metadata Report

Prediction Weighting Layer Used in Population Redistribution

The data presented below represent the predicted number of people per ~100 m pixel as estimated using the random forest (RF) model as described in Stevens, et al. (In Press). The following pages contain a description of the RF model and its covariates, their sources and any metadata collected for each covariate. The prediction weighting layer is used to dasymetrically redistribute the census counts and project counts to match estimated populations based on UN estimates for the final population maps provided by AfriPop, AsiaPop and AmeriPop.

plot of chunk predict_density

Senegal Census Data and Observed Population Density

These data are the population density values used to estimate the RF model used to create the prediction weighting layer you see above. Values represent population density as measured by people per hectare and calculated from population counts within each census unit. These values are used as the dependent variable during model estimation.

Senegal official population estimates, 2009, Admin-level 4

Folder: Census
File Name: admin.shp
Source: Agence Nationale de la Statistique et de la Démographie, Senegal
Description: Required fields for map production are ADMINID and ADMINPOP.
Class: polygon
Derived Covariates:
area, buff, zones,

class       : SpatialPolygonsDataFrame 
nfeatures   : 332 
extent      : 227042, 896103, 1361978, 1845432  (xmin, xmax, ymin, ymax)
coord. ref. : NA 
nvariables  : 8

plot of chunk census_data


Random Forest Model and Diagnostics

These output and figures outline the estimated RF model that is used to predict the population density weighting layer. The model is fitted to the population density values for the preceding census data using covariates aggregatedfrom the ancillary data sources summarized following the model diagnostics.

[1] "Random Forest model is a merged RF model using models from:"
GMB, SEN,   

Call:
 randomForest(x = x_data, y = y_data, ntree = popfit$ntree, mtry = popfit$mtry,      nodesize = length(y_data)/1000, importance = TRUE, proximity = TRUE) 
               Type of random forest: regression
                     Number of trees: 1000
No. of variables tried at each split: 7

plot of chunk random_forest

Error: 'data' must be of a vector type, was 'NULL'

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Covariate Metadata

Senegal Classified Land Cover

Folder: Landcover
File Name: refined_lc.tif
Source: GlobCover, 300m
Description: Landcover from the GlobCover product resampled to 100m, refined with detailed Landsat-derived settlement extents (Tatem et al. 2004,2005), reclassified to match AfriPop coding and eventually broken down into binary classifications by aggregated land cover type (see Linard, et al., 2010 and Gaughan, et al. 2013 for category information).
Class: raster
Derived Covariates:
cls011, dst011, cls040, dst040, cls130, dst130, cls140, dst140, cls150, dst150, cls160, dst160, cls190, dst190, cls200, dst200, cls210, dst210, cls230, dst230, cls240, dst240, cls250, dst250, clsBLT, dstBLT,

class       : RasterBrick 
dimensions  : 5035, 6816, 34318560, 1  (nrow, ncol, ncell, nlayers)
resolution  : 100, 100  (x, y)
extent      : 224515, 906115, 1351935, 1855435  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=28 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0 
data source : D:\APRF\RF\data\SEN\Landcover\Derived\landcover.tif 
names       : landcover 
min values  :        11 
max values  :       240 

plot of chunk covariate_reports


MODIS 17A3 2010 Estimated Net Primary Productivity, 1km

Folder: NPP
File Name: DEFAULT: MODIS 17A3 2010
Source: United States Geological Survey (USGS)
Description: MODIS 17A3 version-55 derived estimates of net primary productivity for the year 2010, estimated for 1km pixel sizes and subset and resampled to match the available land cover and final population map output requirements.
Class: raster
Derived Covariates:
,

class       : RasterBrick 
dimensions  : 5035, 6816, 34318560, 1  (nrow, ncol, ncell, nlayers)
resolution  : 100, 100  (x, y)
extent      : 224515, 906115, 1351935, 1855435  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=28 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0 
data source : D:\APRF\RF\data\SEN\NPP\Derived\npp.tif 
names       :   npp 
min values  :     0 
max values  : 13663 

plot of chunk covariate_reports


Suomi NPP VIIRS-Derived 2012 Lights at Night, 15 arc-second

Folder: Lights
File Name: DEFAULT: VIIRS 2012
Source: http://ngdc.noaa.gov/eog/viirs/download_viirs_ntl.html
Description: These 'Lights at Night' data were derived from imagery collected by the Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor. Data were collected in 2012 on moonless nights and though background noise associated with fires, gas-flares, volcanoes or aurora have not been removed it represents the best-available data for night-time light production.
Class: raster
Derived Covariates:
,

class       : RasterBrick 
dimensions  : 5035, 6816, 34318560, 1  (nrow, ncol, ncell, nlayers)
resolution  : 100, 100  (x, y)
extent      : 224515, 906115, 1351935, 1855435  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=28 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0 
data source : D:\APRF\RF\data\SEN\Lights\Derived\lights.tif 
names       : lights 
min values  : -0.039 
max values  :    290 

plot of chunk covariate_reports


WorldClim/BioClim Mean Annual Temperature 1950-2000, 30 arc-second

Folder: Temp
File Name: DEFAULT: BIO1
Source: http://www.worldclim.org/current
Description: WorldClim/BioClim 1950-2000 mean annual precipitation (BIO12) and mean annual temperature (BIO1) estimates (Hijmans et al., 2005) were downloaded, mosaicked and subset to match the extent of our land cover data for the mapping of this region.
Class: raster
Derived Covariates:
,

class       : RasterBrick 
dimensions  : 5035, 6816, 34318560, 1  (nrow, ncol, ncell, nlayers)
resolution  : 100, 100  (x, y)
extent      : 224515, 906115, 1351935, 1855435  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=28 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0 
data source : D:\APRF\RF\data\SEN\Temp\Derived\temp.tif 
names       : temp 
min values  :  223 
max values  :  301 

plot of chunk covariate_reports


WorldClim/BioClim Mean Annual Precipitation 1950-2000, 30 arc-second

Folder: Precip
File Name: DEFAULT: BIO12
Source: http://www.worldclim.org/current
Description: WorldClim/BioClim 1950-2000 mean annual precipitation (BIO12) and mean annual temperature (BIO1) estimates (Hijmans et al., 2005) were downloaded, mosaicked and subset to match the extent of our land cover data for the mapping of this region.
Class: raster
Derived Covariates:
,

class       : RasterBrick 
dimensions  : 5035, 6816, 34318560, 1  (nrow, ncol, ncell, nlayers)
resolution  : 100, 100  (x, y)
extent      : 224515, 906115, 1351935, 1855435  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=28 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0 
data source : D:\APRF\RF\data\SEN\Precip\Derived\precip.tif 
names       : precip 
min values  :    154 
max values  :   1579