Isoline map

Isoline maps are maps that use continuous lines to join points of the same value, i.e. equal altitudes (contour lines); equal temperatures (isotherms), etc...

The above Isoline map uses isothermic lines to divide up the continent of Australia into areas of equal tempatures during a typical month of January. So the two areas encompassed by cirlces/lines indicating 95 degrees means that entire area averages 95 degrees during the month of January.
http://mapmaker.rutgers.edu/355/interpolating-70-deg-contou.gif

Proportional Circle Map

Proportional circles map are statistical maps that use a series of circles in increasing/decreasing size to illustrate proportional quantititative measurements. The size of the circle associated with each area of the map is proportional to the variable being described on the map. For instance, the above map is a map of Europe with circles of variable sizes assoicated with each country. These circle proportionately represent the amount of internest users within each country. As you can see, Denmark (one of the smaller nations in Europe) has roughly the same amount of internet users as Norway or Sweden (countries several times bigger than Denmark).
http://www.geog.ucsb.edu/~jeff/gis/proportional_symbols_files/map2.jpg

Choropleth Map

Choropleth maps portray quantitative data as colors showing the density, percent, average value, or quantity of a phenomenon within the boundary of a certain geographic area. Sequential colors (color gradients) indicate increasing positive/negative data values.


A Choropleth map is a type of thematic map in which areas are shaded in proportion to the measurement of the variable being displayed on the map. Some examples include population density or political affiliation. It provides an easy way to visualize how a measurement varies across a geographic area. It also shows the level of variable within a region.
The above choropleth map shows areas of increasing harvest amounts if hay. The darker colors indicate areas of larger hay harvesting.
http://www.nass.usda.gov/research/atlas02/Crops/Hay%20and%20Forage%20Crops%20Harvested/Hay%20-%20All%20Hay%20Including%20Alfalfa,%20Other%20Tame,%20Small%20Grain,%20and%20Wild,%20Harvested%20Acres-choropleth%20map.gif

Dot Distribution map

Dot Distribution maps portray quantitative data as a dot, which represents a number of any particular phenomenon in question found within the boundary of a certain geographic area. The pattern of distributed dots reflects the general locations where the phenomenon most likely occurs. The pattern and number of dots within a geographic area reveal the density of the phenomenon in question. There are 2 types of dot-distribution maps: the first type is a traditional dot map showing the distribution of a phenomenon; and the second type is an increase/decrease dot map. This ype of dot-distribution map shows increasing (positive) and decreasing (negative) values of a phenomenon.

Dot distribution maps are especially helpful in showing population, portraying quantitative populations as dots. Say I wanted to illustrate population of the United States, with each dot representing a defined number of people. Below is a representation of what this would look like:

The white areas are the most populated areas of this nation, according to the 2000 census. each white dot represents a specific number of people, so those areas where the white dots are more concentrated are more densely populated.

http://www.census.gov/geo/www/mapGallery/images/2k_night.jpg

Propaganda map

Propaganda maps are political maps of collapse and possibilities. In other words, they illustrate the possible or desired outcomes of wars and conflicts. For example, the propaganda map below illustrates what Europe would have possibly have looked like, had Germany won WWII:


However, not all propaganda maps center around wars. Propaganda maps can be any map geared at influencing the behaviors and opinions of large numbers of people in order to acheive a desired outcome. Their main purpose is to influence or suade their audience in a certain direction. The map above was probably used to help suade other Germans into the war effort, depicting a future of great power and wealth for all Germans alike.
When thinking of propaganda maps, the game of "Risk" pops into my mind, of conquering the lands of your opponent and expanding your empire across the board.
http://strangemaps.files.wordpress.com/2006/09/sur-le-vif-germany-wins-001.jpg

Hypsometric map

Hypsometric maps represent the differing elevations of the earth's terrain through the use of shading and colors. Hypsometric colors are most common in small scale topographic maps and are applied as continuous gradients or intervals. Most often the shading gradient will begin with lighter/brighter colors depicting the lower levels of elevation, and as the elevation increases the shading becomes darker and darker. This is illustrated on the hysometric map of the Greek island of Boiotia. On the left hand portion of the map you can see the dark areas of shading which represents the highest points of elevation on the island, most likely a mountain.

http://www.uam.es/proyectosinv/sterea/beocia/images/figure_8_gis.jpg

PLSS Map

The PLSS is a way of subdividing and describing land in the US. It is used to divide public domain lands (lands owned by the federal gov't). This area encompasses major portions of 30 southern and western states (excluding the original 13 colonies as well as Texas). PLSS maps divide these lands into 6 mile square townships, which are each further divided into 1 mile square sections, which are then divided into quarters, then divided into quarter-quarters and so on. the above map illustrates this concept. Each block within the bold red lines indicates a separate "township" and the smaller sections within each townships are the 1 mile square sections.

The PLSS is a rectangular survey sytem that consists of a series of separate surveys. Most PLSS surveys begin at an initial point, and townships are surveyed north, south, east, and west from that point. The north-south line that runs through the initial point of each township is a true meridian and is called the Principal Meridian. There are 37 Principal Meridians, each is named, and these names are used to distinguish the various surveys. The east-west line that runs through the initial point of the township is called a base line. This line is perpendicular to the Principal Meridian.

Each township is identified with a township(North-South) and range (East-West) designation which indicate the location north south east or west of the Principal Meridian. For example, a township might be identified as Township 7 North, Range 2 West, which would mean that it was in the 7th townships north of a baseline, and 2nd township west of a principal meridian.
Below is a PLSS map illustrating the principle meridians and baselines for the southern states of the PLSS system.

http://www.rootsweb.ancestry.com/~alfrankl/missalalou.jpeg