Sierra Leone - Population Counts

<b>WorldPop produces different types of gridded population count datasets, depending on the methods used and end application. 
Please make sure you have read our <a href="https://www.worldpop.org/methods/populations" target="_blank">Mapping Populations</a> overview page before choosing and downloading a dataset.</b> 
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Bespoke methods used to produce datasets for specific individual countries are available through the <b>WorldPop Open Population Repository (WOPR)</b> link below. 
These are 100m resolution gridded population estimates using customized methods ("<a href="https://www.worldpop.org/methods/populations" target="_blank">bottom-up</a>" and/or "<a href="https://www.worldpop.org/methods/populations" target="_blank">top-down</a>") developed for the latest data available from each country. 
They can also be visualised and explored through the <a href="https://apps.worldpop.org/woprVision/" target="_blank">woprVision App</a>.
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The remaining datasets in the links below are produced using the "<a href="https://www.worldpop.org/methods/populations" target="_blank">top-down</a>" method, 
with either the unconstrained or constrained top-down disaggregation method used. 
Please make sure you read the <a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">Top-down estimation modelling overview page</a> to decide on which datasets best meet your needs. 
Datasets are available to download in Geotiff and ASCII XYZ format at a <u>resolution of 3 and 30 arc-seconds (approximately 100m and 1km at the equator, respectively)</u>:
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- Unconstrained individual countries 2000-2020  ( 1km resolution ): Consistent 1km resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">unconstrained top-down methods</a> for all countries of the World for each year 2000-2020. 
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- Unconstrained individual countries 2000-2020 ( 100m resolution ): Consistent 100m resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">unconstrained top-down methods</a> for all countries of the World for each year 2000-2020. 
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- Unconstrained individual countries 2000-2020 UN adjusted ( 100m resolution ): Consistent 100m resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">unconstrained top-down methods</a> for all countries of the World for each year 2000-2020 and adjusted to match United Nations national population estimates (UN 2019)
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-Unconstrained individual countries 2000-2020 UN adjusted ( 1km resolution ): Consistent 1km resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">unconstrained top-down methods</a> for all countries of the World for each year 2000-2020 and adjusted to match United Nations national population estimates (UN 2019).
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-Unconstrained global mosaics 2000-2020 ( 1km resolution ): Mosaiced 1km resolution versions of the "Unconstrained individual countries 2000-2020" datasets.
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-Constrained individual countries 2020 ( 100m resolution ): Consistent 100m resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">constrained top-down methods</a> for all countries of the World for 2020.
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-Constrained individual countries 2020 UN adjusted ( 100m resolution ): Consistent 100m resolution population count datasets created using 
<a href="https://www.worldpop.org/methods/top_down_constrained_vs_unconstrained" target="_blank">constrained top-down methods</a> for all countries of the World for 2020 and adjusted to match United Nations national 
population estimates (UN 2019).
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Older datasets produced for specific individual countries and continents, using a set of tailored geospatial inputs and differing "top-down" methods and time periods are still available for download here: <a href="https://www.worldpop.org/geodata/listing?id=16">Individual countries</a> and <a href="https://www.worldpop.org/geodata/listing?id=17">Whole Continent</a>.
  
Data for earlier dates is available directly from WorldPop.  
  
WorldPop (www.worldpop.org - School of Geography and Environmental Science, University of Southampton; Department of Geography and Geosciences, University of Louisville; Departement de Geographie, Universite de Namur) and Center for International Earth Science Information Network (CIESIN), Columbia University (2018). Global High Resolution Population Denominators Project - Funded by The Bill and Melinda Gates Foundation (OPP1134076). https://dx.doi.org/10.5258/SOTON/WP00645

Tags: baseline population, geodata
Organization: WorldPop