Line generalization is important in cartography in that it reduce the volume of data while at the same time preserves positional information. For this project, I generalized a small portion of the U.S. map, the country Madagascar and measured its line lengths in order to see how much volume data was reduced.I found that approximately 25% of the volume data was reduced at 100% generalization as we can see from the table below.
I found that as the x-axis (% generalized) gets bigger, the y-axis (line length) gets smaller. The reason that line length does not increase in proportion to detail is because the two variables have an inverse relationship, meaning as one goes up the other one will go down. Therefore, the more a map get generalized, the more details it will lose, so the lengths of lines will decrease.
The measurements that I got over 4 line segments was enough to tell me that a map that is 100% generalized would have shorter line lengths than the original map. The methods that I used to achieve the measurements for this project go as follow:
1.) Generalized a world map found on mapshaper.org by using the Douglas-Peucker method.
2.) Measured the line length of a small portion of the map, Madagascar, of the original map as well as the line length of the generalized map on MapWindow GIS, before exporting the maps out for editing.
The table above shows the result that was gotten from the measurement of the line lengths of the two graphics. As we can see from the table above, the total line length of the generalized map is smaller than that of the original map.
Below is a depiction of the graphics that I was working with in MapWindow GIS, with the green line showing the original lines as it would look like on a world map, and the blue line showing that area of the map as being generalized at 100% with 0% of the original graphic retained.
After I finished measuring the graphics, I then exported them from MapWindow GIS along with the north arrow, scalebar, and legend, and imported all of these elements into Inkscape. I then combined the north arrow, scalebar, legend, and graphics into one map. However, I did not like the layout of the map so I then imported them into paint and used the select feature in paint to move them around until I felt satisfied with the layout of the map.
I then imported this file into ArcMap and added an inset overview map, a title, and neatline. Finally, I imported the map into GIMP and added background colors to the map to make it look nice. Below is the final turnout of my project.
