Map climatic features as the long-term mean values (of atmospheric pressure, temperature, humidity, total precipitation, and so forth) to connect points with equal values of the feature in question—for example, isobars for pressure, isotherms for temperature, and isohyets for precipitation. Isoamplitudes are drawn on maps of amplitudes (for example, annual amplitudes of air temperature—that is, the differences between the mean temperatures of the warmest and coldest month). Isanomals are drawn on maps of anomalies (for example, deviations of the mean temperature of each place from the mean temperature of the entire latitudinal zone). Isolines of frequency are drawn on maps showing
Map symbolization locations. These symbols can be true points or conceptual points. True points represent real objects or the exact location of a tangible object. This could be an oil well or fire hydrant. A conceptual point represents the center of the enumeration unit, such as a corn field. The raw data on proportional symbol maps go hand in hand with the data shown on choropleth maps. Isopleth maps use isolines that connect points of equal values. A good example of isolines is connecting areas with similar temperatures. As with choropleth maps, Isopleth maps require standardized data to be appropriately contoured. Dot