Figure 1
From: The Catalan Surveillance Network of SARS-CoV-2 in Sewage: design, implementation, and performance
Map showing the location, the assisted population, and the sampling frequency of the 56 WWTPs finally selected within SARSAIGUA. Population density is shown using a grid with a resolution of 0.25 km23. Population density information was obtained from the Global Human Settlement Population Grid 2015 (European Joint Research Center, https://ghsl.jrc.ec.europa.eu/ghs_pop.php). The main map has been built using QGIS 3.22 (https://www.qgis.org/en/site/) and county limits obtained from the Cartographic and Geological Institute of Catalonia (https://www.icgc.cat/ca/Descarregues/Cartografia-vectorial/Divisions-administratives). The upper map has been obtained from the ArcGIS Hub using ESRI data (https://hub.arcgis.com/datasets/esri::world-countries-generalized).
