Answer:
ill explain on the bottom
Explanation:
Disadvantages of Choropleth Maps
Although choropleths give a good visual impression of change over space there are certain disadvantages to using them:
They give a false impression of abrupt change at the boundaries of shaded units.
Choropleths are often not suitable for showing total values. Proportional symbols overlays (included on the choropleth map above) are one solution to this problem.
It can be difficult to distinguish between different shades.
Variations within map units are hidden, and for this reason smaller units are better than large ones.
Isopleth maps
Isopleth maps differ from choropleth maps in that the data is not grouped to a pre-defined unit like a city district. These maps can take two forms:
Lines of equal value are drawn such that all values on one side are higher than the "isoline" value and all values on the other side are lower, or
Ranges of similar value are filled with similar colours or patterns.
This type of map is ideal for showing gradual change over space and avoids the abrupt changes which boundary lines produce on choropleth maps. Temperature, for example, is a phenomenon that should be mapped using isoplething, since temperature exists at every point (is continuous), yet does not change abruptly at any point (like population density may do as you cross into another census zone). Relief maps should always be in isopleth form for this reason.
