Fig. 2From: Relationship between freshwater harmful algal blooms and neurodegenerative disease incidence rates in South KoreaThe approach used for digitization of chlorophyll-a monitored sites. Examples are shown using the sites in Seoul with a large river transecting the city and many tributary streams. (a) Number of people in the 1 km × 1 km grid. (b) Locations of chl-a monitored. (c) Overlaying gridded population over chl-a monitored sitesBack to article page