A triangular plot uses three variables compared to one another. This map uses three different areas of the Aelutian islands to compare the Hmax off Kaui for various slip allocations.
A wind rose is a tool used to determine the distribution of wind speed and direction for a given location. They are always in circular form and depict every direction. This wind rose example does not say what location the data is from, but one can easily assume that wind was coming from the southeast a majority of the month at a wide variety of speeds.
Population Profiles are often portrayed in a pyramid-like form representing population statistics over a given time. This map is of Saxony, and it represents a very backwards trend, with a small infant population and a lare adult population, which could imply lack of reproduction or high infancy death rates. For developed countries, there is usually a much more defined pyramid-like shape to the population profile.
A scatter plot is used to plot the data of two variables in order to determine a pattern, or lack thereof. This scatter plot doesnt represent any particular variable, but illustrates the kind of result a scatter plot may produce, showing an obvious increasing trend.
An index value plot is a graph that plots the data of a variable within a range rather than plotting specific points. This map shows the average streamflow index between March and April 2010. http://images.google.com/imgres?imgurl=http://waterwatch.usgs.gov/regplots/real/real_us_2.gif&imgrefurl=http://waterwatch.usgs.gov/%3Fm%3Dreal%26w%3Dplot&usg=__SkLsaX_xX2VHXAW_RzHpPuLd5-8=&h=450&w=550&sz=7&hl=en&start=12&um=1&itbs=1&tbnid=W4WSMU1TKFatsM:&tbnh=109&tbnw=133&prev=/images%3Fq%3Dindex%2Bvalue%2Bplot%26um%3D1%26hl%3Den%26gbv%3D2%26tbs%3Disch:1