Which symbology is most effective for representing population density?

Using graduated colors is particularly effective for representing population density because it visually conveys the variation in density across different areas on a map. This method employs a range of colors where lighter shades might indicate lower density populations, while darker or more vibrant colors represent higher densities. Such a visual gradient allows viewers to quickly and intuitively understand where population concentrations lie without needing to interpret numerical values.

In contrast, point symbols might be suitable for indicating specific locations, but they lack the ability to communicate density effectively across larger areas. Isoline patterns, such as those used in contour maps, are ideal for continuous phenomena but can be more complex and less intuitive for representing discrete population data. Unique values are useful for categorical data, helping to distinguish different groups, but they do not provide a sense of intensity or concentration, which is crucial when analyzing population density. Thus, graduated colors stand out as the most effective means for illustrating variations in population density on thematic maps.