Communicating GIS Lab 6

This week we experimented with Choropleth maps. We learned different classification techniques and what each are useful for. I was able to create a few maps to practice my skills with the symbology and color ramps. One of the big learning points for me was the use of normalized data rather than raw data. The normalized data allows the creator to successfully display the information accurately while raw data would have no real meaning being classified.

The culmination of Lab 6 was our choropleth map of Colorado population change between 2010 and 2014. For my classification I used 6 classes in order to get 0% between two classes. I chose a color ramp of diverging red and green to show an increase in population with green hues and a decrease in population with red hues. The 6 classes were separated using the natural breaks classification. This gave me an accurate representation for all of the data without skewing the classes. I then adjusted the middle class to begin at 0%.

For the legend I ordered the classes to show the increasing percentages at the top and decreasing percentages at the bottom with their respective symbols. I rounded the percentages to two decimal places since the percentages were generally small. For the title and description I used the Population change and the years it occurred.

Communicating GIS Lab 5

Proportional symbol mapping can be a useful tool when trying to display numerical data based on certain features. This week we experimented with the symbology and how to effectively communicate data to the user. Proportional symbology allowed us to use different sized symbols to represent specific numerical values for different areas. With the areas being proportional to each other based on the data it made it easy for users to draw conclusions based on the data. 

One particularly interesting feature we worked with was how to display positive and negative numerical data using the proportional symbol mapping. In the map below you can see that the same proportional symbols can be used creatively to display a positive value of the data (Green) and a negative value (Red). 

With the symbols staying the same size proportionally based on the absolute value of the numerical data we had to represent them as neutral in the legend and then explain the coloring system. This was a neat solution to an interesting problem. At first it seemed difficult to display the wide range of data in this map with something other than color ramps, but the proportional symbology made it quite simple in the end.

I think this type of symbology also grabs the users attention better than using a color ramp. With different sized objects representing data on a map it draws the users attention immediately to the fact that one is bigger than the other. Rather than seeing a specific color and wondering what that color represents the user can identify that one area has more of something or is larger in a number of something than another area without referencing the legend. This could be extremely useful in quick reference products where the title explains the data.

Communicating GIS Lab 4

This week we are working with color progressions and experimenting with linear vs. adjusted color ramps. The linear progression makes the most sense mathematically when it comes to choosing colors in a ranking scale. The darker shades are definitely harder to distinguish from one another. I did not think they would be as close as the lab described, but it definitely shows in the color ramps. For this reason I think the adjusted progression is the most effective. The color ramp clearly separates the darker shades more than the lighter ones. With my adjustment I went with the “1/3” rule the lab described and it seemed to work. I was pleased with the color ramp and would choose the adjusted ramp over the linear one. Then using colorbrew I selected a slightly greener base. The intervals seemed to follow the adjusted progression, but were almost random in a sense. They were generally larger for the darker shades, but had no real pattern. 

Communicating GIS Lab 3

This Lab focused on Typography. We created a map of the San Francisco Area and practices labeling features. The font for the entire map is Arial. I chose to keep the same font for all of the labels in order to keep the map uniform. The only font that was not set to Arial was the Title font which helped to separate it from the rest of the data. The font sizes on the product vary slightly to show a hierarchy. The larger size shows a major city (ex. San Francisco) while the smaller font shows sub-cities. I attempted to use a font size large enough to be legible, but small enough to not distract from the rest of the information. The placement decisions were a little more difficult. Since a dark color was used for park backgrounds and the roads were so numerous on the map I had to be creative and us the text halos and contrasting colors. Overall I attempted to place the labels offset from each other in order to not overlap while allowing spacing for the normal map elements. For these labels I used the standard text tool on the Draw toolbar.

Communicating GIS Lab 2

The area of interest I chose for our Lab 2 deliverable was the state of Texas. I used the custom projection NAD 1983 (2011) Texas Centric Mapping System Albers for the data. I chose this coordinate system due to the fact that Texas spans three UTM Zones and is broken up into five state planes. This central coordinate system is a conical projection with the standard parallels approximately 1/6 from the top and bottom of the state as well as the central median dividing the state equally. Other options were similar projections of an earlier year or used the Lambert projection instead. I chose to stick with the Albers projection to preserve the area of the state. Included on the product are reference grids in geographic coordinates and in projected coordinates. The two sets are show together on the map to compare the measurements and actual lines. 

Many products on the military side are represented in a similar way. For instance a 1:50,000 scale MGRS map used for land navigation and aerial planning has a reference grid labeled with the MGRS coordinates. In the background in a separate color there is also a reference grid for Latitude and Longitude so that the user can compare the two based on how they are navigating.   

Communicating GIS Lab 1

For our first map in the class I had some difficulty getting back into the ArcMAP mindset. It was nice getting to go through the program and relearn how to do things. Slowly, but surely I was able to pull my memories together to come up with my finished product.

For this product we focused on the 5 map design principles:
Visual Contrast- For the background of Travis county I used one of the standard land feature colors of light green. By leaving the background of the map data frame white a good contrast is created making the data easy to see. Since the white background is representing a space without data it is an acceptable color. Legibility- The text in the document is all in the same font of Times New Roman. The familiar font and size of the text allows the users to easily understand what the text is saying. The symbols and features on the map are also represented with realistic colors so that the map portion is easily readable. Figure-Ground Organization- The white background and colored county and features helps the user distinguish between relevant information and areas with no data that are not important to the map. Hierarchical Organization- For this element the main map data is displayed in the very center of the document along with a thick border (neatline). The rest of the information on the document has a thin border and is relatively smaller than the main map portion. This shows the user the importance of the main map data frame. Balance- The size, color, and layering of the symbology on the map data balances all of the information as to not overwhelm the user with specific data. The balance shows that all of the data on the map frame is important and even balances well within the entire document.