Since a bus stop, river, and forest take up space in differing ways, they cannot be represented using the same map symbol. Geographers typically categorize features as points, lines, or areas. Knowing which category a feature falls into will help you create a logical legend, arrange your data into layers, and select appropriate symbols for each feature.
Review any physical or online map and identify nine features. Group these features into categories of points, lines, and areas. Examples of points include landmarks, stations, and trees. Lines can be roads, trails, rivers, and borders. Areas can be lakes, parks, neighborhoods, and land use. Certain features can act as points, lines, or areas depending on scale. For example, a city can be represented as an area on a detailed local map but as a point on a country-wide map.
Point symbols are used to represent features that are too small to be mapped to scale. Symbols should vary in shape, size, and color to allow users to easily differentiate between features, but they shouldn’t overcrowd the map. Varying shapes, such as circles, squares, and triangles, could represent different features. Symbol size could be used to represent quantities, like populations. You shouldn’t use individual pictures for all features, as this could make the map confusing and harder to read, especially if there are multiple points near one another or when the map is printed at a normal scale.
Line symbols represent features that have length and direction. Line width can be used to distinguish between main roads and secondary roads, while color or style could be used to distinguish between rivers, railroads, highways, and boundaries. It’s important to let the map’s user know what type of feature you’re representing without overemphasizing it. Make sure boundaries aren’t so thick that they visually split the map into separate regions, and ensure that lines are distinct enough from one another so that roads and rivers can be easily identified. Pay close attention to where lines intersect to make sure different line features don’t overlap in the same area.
Area symbols enclose a section of the map and often have more visual impact than point or line symbols. Using a few distinct colors to differentiate between types of areas, such as forests, water bodies, residential areas, and neighborhoods, will allow users to easily understand the map’s content without obscuring labels or other details. Bright colors spread over large portions of a map can be overwhelming and obscure smaller symbols, so lighter shades tend to work well for base-map elements. Ensure that color schemes used to compare values or categories are logical, and that each area has a corresponding label in the legend.
After assigning features to point, line, or area symbols, make sure that your map accurately represents these features as points, lines, or areas. Zoom out and look to see which symbols blend in, overwhelm, or disappear. Effective maps don’t always use the prettiest symbol, they just use the simplest symbol that allows each feature to remain distinct.
